The Bell Mountain silica deposit, Towns County, Georgia

CONTRACT NO. Cc-6094 FINAL REPORT
The Bell Mountain Silica Deposit Towns County, Georgia

PART I -

(a) Geologic Study of the Bell Mountain Silica De posit, Towns County, Georgia

(b) Development of a Color-Sorter for Crushed Stone

PART II - Survey of the Market for the Bell Mountain Silica

by
VERNON J. HURST
GEOLOGY DEPARTMENT
and
GEORGE R. HORTON
SCHOOL OF BUSINESS ADMINISTRATION UNIVERSITY OF GEORGIA

in cooperation with the
INSTITUTE OF COMMUNITY & AREA DEVELOPMENT
for the
AREA REDEVELOPMENT ADMINISTRATION UNITED STATES DEPARTMENT OF COMMERCE
Washington, D. C.
1964 Reprinted 1981 by the Georgia Geologic Survey Branch of the Environmental Protection Division, Department of Natural Resources

CONTRACT NO. Cc-6094 FINAL REPORT

PART I

(a) Geologic Study of the Bell Mountain Silica Deposit, Towns County, Georgia
(b) Development of a Color-Sorter for Crushed Stone
by Vernon J. Hurst

PART II

Survey of the Market for the Bell Mountain Silica by
George R. Horton

SUMMARY
Mapping and core drilling at Bell Mountain have proven 2 million tons of silica. The total tonnage might be 1.5-2 times as much. The silica is,varicolored: white, yellow, pink, yellow-brown, red-brown. Coloration' is due mainly to iron oxide released during the decomposition of pyrite finely scattered through the silica. The pyrite is mostly decomposed in the upper 50-75 feet of the mass, and partly decomposed down to depths of 250 feet. Though the stone is generally a little whiter at depth, it is still mostly varicolored. The production of a uniform or high quality silica product requires that the crushed stone be sorted. A device to sort the stone on the basis of color has been developed.
Though the silica deposit at Bell Mountain is being exploited on a limited scale, the expansion of the market is unlikely at current prices (about $35.00/ton). The best potential market is the cast stone trade which offers a large market at prices around $30.00/ton. Thus the size of the market for the Bell Mountain silica depends, at present, on whether the price can be reduced about 15%.
Though there are possibilities for market expansion, a large market does not now exist for the Bell Mountain silica at current prices.

l.
PART I
(a) Geologic Study of the Bell Mountain Silica Deposit, Towns County, Georgia
(b) Development of a Color-Sorter for crushed stone.
by Dr. Vernon J. Hurst, Head
Department of Geology University of Georgia
Athens, Georgia
Contents
Summary -------------------------------- --------- --- -------- 1 Size and Shape of the Silica Deposit --- ------ -- - --- - ----- - - 2
Topographic Mapping --------------------------------- 2 Geologic Mapping ------------------------------------ 2 Core Drilling - -------------- - ----- - --- - - - - -- --- ----- 5 Estimated Tonnage ------------------------------------------ 7 Quality - -- ---------------- -- --------- ----- -- --- ------------ 7 Development of a Color-Sorter for Crushed Stone ------- ----- 9 Need for a Color-Sorter ----------------------------- 9 Light Sensing Assembly -- - ------- ----- ---------- --- -- 9 Light Source ~------------~-------------------------- 14 Power Source ---------------------------------------- 17 General Comments ------------------------------------ 17 Performance ----------------------------------------- 17 Directions for Operating the Color-Sorter - ---------- 20 Acknowledgments -------------------------------------------- 21 Appendix 1 ------------------------------------------------- 22 Appendix 2 ------------------------------------------------- 25 Appendix 3 - -- --- -- ---- - - ------ -- -------- - - -- -------------- - 34 Appendix 4 ------------------------------------------------- 36 Appendix 5 ------------------------------------------------- 39 Appendix 6 ------------------------------------------------- 40
Sununary
Mapping and core drilling at Bell Mountain have proven 2 million tons of silica. The total tonnage might be 1.5-2 times as much. The silica is varicolored: white, yellow, pink, yellow-brown, red-brown. Coloration is due mainly to iron oxide released during the decomposition of pyrite finely scattered through the silica. The pyrite is mostly decomposed in the upper 50-75 feet of the mass, and partly decomposed down to depths of 250 feet. Though the stone is generally a little whiter at depth, it is still mostly varicolored. The production of a uniform or high quality silica product requires that the crushed stone be sorted. A device to sort the stone on the basis of color has been developed.

2.
SIZE AND SHAPE OF THE SILICA DEPOSIT
Topographic Mapping I When the study began, a large scale base map of Bell Mountain was not
available. We therefore made a plane table survey of the Mountain and prepared a topographic map at a scale of 1 to 1200 with a contour interval of 20 feet. This is the map on which geologic data are plotted in Figure 1 and from which the cross-sections of Figure 2 were made. Note that the elevations on the map are relative. The actual elevation of the mountain is a little more than 3360 feet above sea level.
Geologic Mapping I The geologic map (Figure 1) reveals a mass of silica 1600 feet long and
up to 500 feet wide, elliptical in cross section. Bounding the silica on all sides is biotite-gneiss. The western contact between gneiss and silica curves with respect to the contour lines in such a way as to show that the contact dips steeply to the east. TPe eastern contact is less well exposed. The silica mass forms the crest of Bell Mountain and extends northeast-southwest from the top of the mountain, pinching out in both directions. The pinch-out to the south is well exposed and is accurately delineated on the geologic map. Toward the north, quartzite rubble litters the surface to such an extent that the exact manner of pinch-out cannot be mapped, but the silica extends barely beyond the road at the north edge of the map.
Surroundiqg the silica mass is biotite-gneiss which extends south at least a mile and east, north and west to the foot of Bell Mountain. Thus the silica mass is an isolated deposit atop Bell Mountain surrounded on all sides by biotite-gneiss.
A conaistent fracture system is well developed throughout the silica mass. The most prominent fractures strike about N50W and dip about 55

5.
to the southwest. These have served as channelways for downw~rd percolating water, which has facilitated decomposition of fine pyrite scattered through the quartzite. The fractures greatly facilitate quarrying of the stone.
The distribution of the stone's color at the surface was plotted in detail. No pattern other than fracture control can be discerned. The color varies from white through yellow and red to brown within short distances. A boulder size mass white on the outside may show color on the inside when broken. There are few masses as much as 6 feet across of one color.
The coloration was imparted by the weathering of pyrite (iron sulphide) finely scattered through the silica. Water and air from the surface penetrated the silica along fractures and grain boundaries and reacted with the pyrite. Iron thereby released was dispersed by water and where oxidized came out of solution as iron oxide, or hydrous iron oxide, which colors the stone. The color varies with the amount of iron oxide, how thinly it is dispersed and the degree to which it is hydrated. The stone containing no iron is white. Most of the coloration is within the upper 50 feet of the quartzite, though unaltered pyrite can be found within less pervious masses near the surface. Coloration is erratic within the upper 25 feet of the mass.
Though the stone at depth is generally whiter, it also contains unclecomposed pyrite. After this stone has been crushed and expose.d to the weather, some staining will ensue. The most durable white stone can be produced at this site by crushing the near-surface silica, in which most of the sulphide has already decomposed, and sorting out the white pieces after crushing.
Core Drilling A subcontract for core drilling at Bell Mountain was negotiated with

6,
the ABC D~illing Company, Greenville, South Carolina. The d~ill crew moved ~o Bell ~ountain the 12th of Octpber and finiehed
drilling the lOth of December. Drilling was delayed repeatedly by the dry weather and the fact that the drill location is near the top of the mountain. It was_necessary, finally, to string wa~e~ pipe more than 1200 feet up the mountain to the rig.
A mi~imal drilling p~ogram was laid out to test the downward extension of the silica mass, to demonstrate whether or not the pyrite which causes the coloration near the surface also extends to depth, and to obtain samples from which to estimate the quality of the stone at depth. Four holes were d~illed; the~~ location and attitudes are indicated in Figure 1.
Logs of the d~ill eores are presented in Appendix 1. Hole No. 1 was located to test the downward extension of the quartzite on the southeast side. If the mass had been dipping gently eastward, Hole No. 1 would have fixed its position far down-dip, but after coring 112 feet it was apparent that the silica mass does not dip as was expected, so the hole was terminated.
Hole,No. 2 was located closer to the silica mass to insure that it would CQt any downward extension. The relationship of Holes 1 and 2 to the s~rface expos~res of silica is shown in section U-V of Figure 2. Hole No. 2 reached a depth of 251.2 feet and did not encounter the silica. From the fact that the soQthwestern contact of the silica is near verti~al, at the surface, and w~s not encountered in Hole No. 2, it is concluded that the silica does not extend at depth on the southwest end but must terminate shallowly. Nearsurface evidence of faulting suggests a fault plane.
Near the middle of the silica mass on the west side, the manner in which the cont~ct intersects the contour lines shows that it dips steeply to the east. Drill Hole No. 3 was located to find out whether the dip is

7. maintained at depth; ~ee ~ection Q-R of Figur~ 2. The hole began in biotite
gneiss and intersected the ~neiss-si~ica contact at a depth of 118 feet. The gneis~~ailica contact, wh~ch dip~ 70~80 at the surface, must dip less steeply at depth. There is conspicuou$ faulting along the base of the silica both at the ~u~face ~nd at drill depth.
'l'he drill site. for Hole No. 4 was ~ho,sen about 25 feet to the est of wh~r~ it i~ shown in section I-J of Figure 2. Though mistakenly drilled 25 feet closer to the silica, the hole still provides most of the information that was sought. It proves that the s~liea does not pinch-out as a thin sel~ vage Oft the east side, and it provipes a sample of the silica at a 41-foot depth.
The boundaries of the silica mass are shown in Figure 1. Cross-~ections a~e presented in Figure ~
ESTIMATED TO~AGE From the geologic map and the information provided by 4 drill holes enough has been l~arned qf the size and shape of the silica to permit a reliable estimate of to~nage. The eross~aections of F~gure 2 depict the size
',
and shape of the exposed silic$ ~nd show what can be conservatively ded~ced about it8 downward extension. The mass represented by the stippled sections yield~ a value of about 901,900 ~ubic yards, or a little more than 2 million tons of silica. This is a conservative estimate; actual tonnage may be l.S-2 times as much.
Current~y the ailica being removed from Bell Mountain ~ells for more than $30.00 per ton.
QUALITY The Bell Mountain silica is a fine-&raineq, hard quartzite. Its yQ~or

B.
ranges from snow white (N-lO)W to d~rk r~ddish brown (10R3/4). Other common colors are grayi~h pink (5RB/2), grayish yellow (5Y8/4), dark yellowish orange (10YR6/6), pale red (10R6/2), moderate yellowish ~rown (lOYRS/4), ~nd pale reddish brown (lORS/4). The color varie~ erratically within distances of ~eet or even inches. The lighter colors dominate.
The texture varies from vitreous to sugary. The mineralogical co~position is 99i~ quartz. The most abundant accessory mineral is fine pyrite more or less altered to iron oxide. Other access~ry minerals are mica and feldspar. Analyses of the drill cores show considerable variations in the chemi~al composition of the biotite-gneiss, and small variations in the composition of the quartzite. For the biotite-gneiss the sili~a and alumina percentages vary directly with variations in the percentages of qu~rtz and feldspar. Percentage K20
varies with biotite. Percentages of Na 2o and CaO vary principally with the
feldspar content. Due to the compositional banding of the gneiss on both the hand specimen scale and also at a larger scale, the chemical composition of the rock varies greatly from one sample to another, depend~ng on how the sample was taken.
Of more importance is the chemical composition of the quartzite. Again the chemical composition is directly related to the mineralogical composition, but the variation is small. Xray fluorescence analyses of closely-spaced samples from drill hole No. 3 and drill hole No. 4 show a range' in silica from 98.6% to 99.9%, a range in iron from 1.2% to 0.005%, a range in alumina from 0.8% to 0.001%.
* According to the Munsell color system.

9.
DEVELOPMENT OF A COLOR-SORTER FOR CRUSHED STONE
Need for a color-so r t e r The Bell Mo~ntain silica is varicolored. Coloration is due mainly to
iron oxide stain. In order to p~oduce a uniformly colored stone or a high purity silica product it is necessary to have a means of separating the color varieties. This cannot be satisfactorily accomplished by hand picking. Although fist-size or larger chunks of uniform color can be picked out, coloration varies within the large chunks so much that when they are crushed the finer fragments are varicolored. To produce uniform silica chips from this deposit it is necessary to have a mech~nical sorter which can sort the fragments after final crushing.
A pilot size color-sorter has been d~veloped. Its general design is shown in Figure 3. Figure 4 is a photograph of the pilot size model. The feed for the color-sorter is a conveyor belt. Discrimination is affected on the basis of color by the photocells. Rejection of off-color pieces is accomplished by a compressed air jet.
Light Sensing Ass~mbly The light sensing assembly is an array of 6 aluminum tubes, each con-
taining a photocell and a lense, as shown in Figure 5. Three of the tubes have a color filter mounted on one end. Light from the point of discrimination (the point where the color of the falling rock fragment is sensed) is focused onto the photocell of the tube by sliding the inner tube on which the lense E is mounted. The lense focuses the image of the gravel onto the sensitive area of the photocell, when the gravel falls past the point of discrimination. Two photocells are wired into a bridge as shown in Figure 6. One of the photocells is without a filter on the end, the other with filter (either red, blue or green). There are three bridge

10.

Bank of photocells

Point of discrimination
Conveyor belt

Light source

Air jet

Electronics: Power source Color bridges

Figure 3 - Schematic Drawing of Color Sorter

11. Fio.ure 4

A

A

1-f>
E
I

FIGURE 5

Drawing of photocell-lense tube assembly. Actual size. A - Clamping screws. B - Plug of leucite to support the photocell. C - No. 8345 or 8346 RCA photocell. D -Light filter held ia position by spring clamp. E - Lense to focus light from the point of discrimination onto the photocell.

.....
N

q.RFEN .f!JRI/XiE.
Rr- 1?2 - /0/( /OT X /OK };W S% S6 Jl.. IW s~
Kx- 47.Jl tw -f%
I( 1- - 2/( Ti'tlll-pf.
I RP BLUE BRIJ:)qE
R2- /~k pol x /Of<" ~W s 7c
Ry- 4-l..R. IW .S% Rx- 56 -n. 1vv s?o Rf-- Zk Tr/111 -pof. ..r IX J.f W S/o

BRIPCiE CIJ!f'CU/T

Input,-

Plio~ II,
co/or Set151f9

p/}4foce!l,
w1111e llrJJI

..

~U/~?U-f

Figure 6

1~1, -i-
.....
w

14.
circuits, one for each color. The u&e of two photocells in a single bridge circu~t, one sensing mainly colored light and the other sensing the intensity of white light, makes it possible to compensate for variations in the intensity of tpe light due to differences in the reflectivity of the specimen. Without the bridge input being adjusted to the total intensity of the light from the specimen, a change in the resistance of the color sensing photocell might relate only to differences in reflectivity, i.e., to textural differences rather than to light absorption or color differences.
Thus the light entering one photocell is mainly red; that entering a secopd photocell is mainly blue; and that entering a third is mainly green. Each of these photocells is coupled through a bridge with another photocell which receives unfiltered light from the specimen. This arrangement adjusts for differences inreflectance due to differences in granularity, orientation, color, etc. of the stone fragments. The outputs from the three bridge circuits are routed through Schmitt triggers, invertors, NOT switches and a NAND gate to a solenoid driver to actuate an air valve, as shown in Figure 7. The wiring of the bridge power supply, the meter circuit, the Schmitt triggers, the amplifiers, the invertors, the lamR drivers, the NAND gate, the relay drivers and the main power supply are presented in Figure 8. Appendix 3 is a parts list for the color-sorter. Appendix 4 gives the printed circuit card connections. Appendix 5 gives the cable color code for the photo cells. Appendix 6 gives the cable color code for the power supply.
Light source An air cooled General Electric BMA projection bulb is focused onto the
point of discrimination. A thin frosted plate of glass to defuse the light somewhat is interspersed between the light source and the specimen. The light source was selected so as to give intense light through the visible region.

0 Meter Selector Schmitt Trigger
Schmitt Trigger
Schmitt Trigger

I-nvertor

Lamp Driver

NOT Sw-.

Invertor

Lamp Driver

NOT Swe

rnvrtor

Lomp D"river

Figure 7

Relay Driver
Relay
Air
vat..
1-' U1

' '- - .. --.1

;;

::

16.

00

Q)

.
u

~:;
llO .-I

~

.~
;
~
u

,-- ----.
'
. .

! .

17.
Power source The Sorter is designed to operate on 115 volt AC, 60 cycle, single phase
current. For the wiring diagram see Figure 8.
General Comments The circuits for the color-sorter are transistorized to reduce power con-
sumption and insure a minimum of maintenance. The principal circuits are mounted on boards which can be quickly removed and replaced in case of component failure.
The operation of the color-sorter is relatively simple. As a piece of ~rushed stone passes through the point of discrimination, its color is sensed ny the photocells and if it is the desired color it is ejected by the air jet. If it is some other color, the photocells do not actuate the air jet and the fragment ~alls freely. Thus the desired color is separated from other colors as the fragments drop off the conveyor belt.
The basic operation of the color-sorter is detailed in Appendix 2.
Performance The pilot size color-sorter that has been developed conveniently handles
12 pounds of crushed stone per minute in the size range of 1/2-1". During a full day of operation it can sort 8-10 tons of crushed stone. The amount that can be sor~ed is limited by the response time of the photocells and by the speed of the conveyor belt.
After a rock fragment has moved into the field of view of the photocells there is an 11 milliseconds lag before the photocells respond. The other circuits respond in microseconds or less. The sorting capacity of the machine might be increased by finding another type of photocell with a faster response; this would probably necessitate another amplifying section in the photocell circuit, and perhaps some other circuit changes.

18.

In the present design, the conveyor belt speed is 14.3 feet .per minute.

The belt move~ 0.0315 inche~ during the 11 millise~onds required for ~he

photocells to respond. The size of the area being scanned is such that the

specimen might move 0.06 inches dur~ng the 11 milliseconds lag without the

particle beginning to pass out of the field of view. Therefore, the presertt

conveyor belt speed can be doubled. After doubling the belt speed and making

l

!

a few adjustments (position of the air jets, position of the ligh~ source,

and photocells) this sorter will handle 16-18 tons of crushed stone per day.

As the color-sorter now stands, it is a workable machine. It is con-

structed of dur~ble components, can be cheaply operated, and a bank of color-

sorters can handle the output of all the Bell Mountain operation.

For full scale operation, the light sensing unit (A in Figure 4b) would

be mounted at the end of a regular conveyor belt (not the narrow belt D

shown in Figure 4a~j the air jet (C in Figure 4, B in Figure 4b) would be

propetlY positioned; guides such as E in Figure 4a would be placed to correct-

ly position the silica fragments moving on the conveyor blet; the light (B in

Figure 4a) would be focused onto the point of focus of the photocells in the

the light ~~nsing assembly; the air solenoid would be connected to a compressed

air line; and the power supply connected to a 115 volt AC 60 cycle source.

Thus could the color sorting unit that has been constructed be placed directly

into commercial operation. The power supply (D in Figure 4b) can be placed ~t

any convenient spot by lengthening the cables connecting it with the other

components. The controls (panel C in Figure 4b) might be placed anywhere

near th~ light sensing assembly, protected from possible dama~e by falling

rock.

The color-sorte~ that has been developed can sort 16-18 tons of silica

crushed to 1/~-1 11 fragments per day. The cost of the components is about

$400.00 dollars. The components pan be bought and assembled for less than

$1~000.00.

19 .
Small changes in the design can permit the unit to sort other particle sizes. The sorting of ~mallef size' reduces the rate of sort~ng, the putput, The sorting of larger ~izes increased the rate, but larger pieces of the Bell Mou~tain silica are not homogeneous: only a less homogeneous product can be p~oduced by sorting larg~r size~.
The total production of stone at Bell Mountain can be handled by using several sorting units. The sized stone from the crusher can be distributed to several conveyor belts, each handling the capacity of one sorter. The tons of stone produced each day divided by 16 is the number of sorters needed. The sorted tone being worth $30/ton, ~a~h sorter can put out about $480.00 worth of atone per day. Seven sorters can easily handle a million dollars worth of stone per year,
Any d~vice can be improved. Coneiderable improvement can be e~pected in n~w devices such as the color-sorter which we have developed. Seve~al improvements can he suggested now: (1) another type of photocell with a faster response might he found ~this, and ~ faster conveyor belt speed, might double or triple sorting capacity; (2) for the air jet at right angles to the belt a small "flip-flop" baffle actuated by a solenoid might be substitut~d ~ it could be placed ~t the end of anq just below the conveyor belt in the vertical plane defirted by the moving stone - a small "flip-flop" action of the b~ffle could accept or re)ect the individual particles as they fall off the conveyor belt and are scanned by the light sensing assembly; (3) the tubes holding the photocells and light focusing lenses could be made smaller, and tightly clu~tered about the light source ___ this would reduce parallax from variations in the po~ition of falling parti~les ----- ~11 the photocells could then sense the light r~flected from the same pa~ticle aprfaces. Other improvement might be suggested. The possibility of improvi~g a devide continues indefinitely.

I .
20 .
A pilot~size color sorting device has been assembled and modified to the point that it is comrne~cially useable. Parts lists, wiring diagrams, and arrangement of components are given in this report. A finished device is available for copying, as specified in the contract under which it w~s developed.
Directions for Operating the Color-Sorter Plug power supply into 110 volt, single phase, 60 cycle source, and
connect tube from light source to compressed air. Adjust air flow to bulb to keep it cool. Connect the air jet solenoid to the compressed air source at a pressure of 60-150 psi.
Throw line switch on. Turn meter selector switch to G (green circuit) and adjust the balance resistor for green (G on the right side) by inserting a small screwdriver into hole G and turning until the meter reads minus 10 microamps. Turn m~ter selector switch to blue and repeat, then to red and repeat. Now turn meter selector switch tp off. Place white object at point of discrimination and adjust color sensitivity control for each of the three color circuits so that the colored bulb for each lights up. The "air-on" bulb will now be lit. The unit is ready for operation. Adjusted in this manner, the air jet will eject those specimens which reflect the three wave lengths of light equally, i.e., white specimens, as they fall off the conveyor belt. Pushing down on the NOT switch for a given circuit will cause the specimen to be ejected only when that particular wave length is heavily absorbed. Thus by adjusting the color sensitivities for the three circu~ts and by changing the NOT switches, the unit can be made to preferentially select any color. For example, if it is desired to select red specimens and reject white, put the NOT switches for the green and blue circuits in the down position. White specimens reflect all 3 colors: red, green, and blue. Red specimens on the other hand, reflect most of the red, but absorb part of

21.
the green, and ~ven more of the blue. Putting the NOT swit~hes for the green and blue circuits in the down positions causes the ai~ jet to be trigg~red pnly when the specimen absorbs green and blue, i.e., when the specimen is red. Settings tor ~he thre~ sens~tivity cqntrols and corresponding positions fo~ the NOT switches can .be set up for the preferential selection of any color.
ACKNOWLEDGEMENTS
Mr. James ~ed, University of Georgia Electronics Shop, helped with the design pf the electronic circuits a~d ordered and assembled the electronic components.

22.
APPENDIX 1

Log

Drill Hole No. 1, Bell Mountain, Towns County, Georgia,

drilled 10/22/63-10/25/63. For location, see Figure 1.

Depth 0 - 30
3o - :n .5
31.8 - 33.4
33.4 - 34.0
34.0 - 35.0 35.0 - 37.0 37.0 - 37.4 37.4 - 87.0
87.0- 91.0 91.0 - 92.5 92.5 - 94.0 94.0 - 110 110 - 112

Description Overburden.
Fine-grained biotite gneiss, weathered.
As above, but with coarse quartzose-feldspathic blebs, patches and streaks.
Anhedral to subhedral masses and patches of feldspar-quart~ (1 mm-1 em) in diameter with patches and "swirls" of brown mica mixed with gneiss as above.
Gneiss as at 30 - 31.5.
Gneiss as at 33.4 - 34.0.
Weathered zone of gneiss as at 30 - 31.5. Broken fragments.
Gneiss as at 30 - 31.5 and 33.4 - 34.0. Slight sulfide mineralization along foliation at 40.5, 43.9, 45, 55.3, 55.6, 57, 57.10, 79.11.
At 66.7- 69.4 masses of subhedral feldspar phenocrysts.
Feldspathization more pronounced.
As at 37.4 - 87.0.
As at 87.0 - 91.0.
As at 37.4 - 87.0.
As at 87.0 - 91.0.

Log
0 - 19 19 - 105

Drill Hole No. 2, Bell Mountain, Towns County, Georgia. For location see Figure 1.
Overburden.
Migmatized, fine-grained biotite gneiss~ locally garnetiferous. Coar~e-grained quartzo-feldspathic gneiss is in crenulated bands, irregular patches and thin layers. 3/4" quartz vein at 81.8. Ptygmatic type folding frequent in quartzo-feldspathic bands and patches.

23.

Depth 105 127 127 - 251.2

~ription
Same as above, migmatization increases.
As at 19 - 105. Vein quartz 139.10 - 140.9. Also at 243.3. (Slight iron sulfide mineralization).

Log - Drill Hole No. 3, Bell Mountain, Towns County, Georgia. Drilled 11/18/63-11/26/63. For location see Figure 1.

0 - 18 18.0 ~ 19.6 19.6 - 21.6
21.6 - 26.4
26.4 - 26.9 26.9 - 27.9 27.9 - 41.0
41.0 - 45.0
45.0 - 47'.5 47.5 60.8 60.8 - 61.11 61.11 - 62.6 62.6 - 62.10 62.10-63.9 63.9 - 66.0 66.0 - 67.2 67.2 - 71.5 71.5 - 74.5 74.5 - 75

Overburden.
Fairly homogeneous, fine-grained granitic gneiss.
Zone of micaceous gneiss containing numerous feldspar porphyroblasts up to 1/2" across.
As at 18.0 - 19.6. Thin quartzo-feldspathic bands approximately parallel foliation.
As at 19.6 - 21.6.
As at 18.0 - 19.6.
Iron sulfide mineralization at 28. Garnetiferous gneiss at 37.0 - 37.6 and 40.5 - 41.0.
Homogeneous, fine-grained biotite gneiss, faintly gneissic.
Gneiss as at 19.6 - 21.6 and 27.9 - 41.0.
Coarse gneiss. Iron sulfide at 48.8.
Gneiss as at 18.0 - 19.6.
Coarse gneiss as at 47.5 - 60.8.
Gneiss as at 18.0 - 19.6.
- Coarse gneiss as at 47.5 60.8. - Gneiss as at 18.0 19.6. - Gneiss as at 47.5 60.8. - Gneiss as at 18.0 19.6.
Gneiss as at 47.5 - 60.
- Gneiss as at 18.0 19.6.

24 . ,

Depth 75 - 75.8 75.8 - 75.ll 75.11 - 77.8 77.8 - 79.8 79.8 - 80.8 80.8 - 83.6 83.6 85.6 85.6 - 89.0 89.0 - 102.7
102.7 - 118 118 - 118.3 118.3 - 119
119 - 129 129 - 133

Description Gneiss as at 47.5 - 60. Gneiss as at 18.0 - 19.6. Gneiss as at 47.5 - 60. Gneiss as at 18.0 - 19.6. Gneiss as at 47.5 - 60. Gneiss as at 18.0 - 19.6. Gneiss as at 47.5 60. Gneiss as at 18.0 - 19.6. Gneiss as at 47.5 - 60. Iron sulfide mineralization at 101.4. Gneiss as at 18.0- 19.6. Stained quartz. Coarse-grained quartzo-feldsp~thic gneiss; feldspar kaolinized. Coarse mica schist with large feldspar porphyroblasts. Stained quartzite.

Log - Drill Hole No. 4, Bell Mountain, Towns County, Georgia. Drilled 12/6/63-12/10/63. For location see Figure 1.

0 - 27 27 - 27.4
27.4 - 33.10 33.10 - 34.4 34.4 - 41.0

Overburden.

Pitted and vugged, stained quartzite, limonite stains and crusts surfaces.

Stained quartzite.

Cavity.

33.5 Vein of iron sulfide 1/8" thick.

Stained quartzite.

35.1 Vein of iron sulfide 3/411 thick.

Vein of iron sulfide 1/211 thick

at termination of hole.

25 .
APPENDIX 2
SUMMARY OF THE OPERATION OF THE COLOR SORTER
Theory of Operation
The color-sorter consists of three Wheatstone Bripges, their assoela~ed Schmitt triggers, amplifiers, ~nvertors ~nd ~amp drivers, plus an NAND gate, relay driver, relay, a solenoid air valve, and a mqnitor meter (see Figure 7).
By properly adjusting the three primary color bridges (effe~tively mixing the three primary colors in various proportions) anq by placing the NOT switches in the proper positions any color in the spectrum can be singled out.
Basic Operation
The RED bridge is adjusted by means of R3 and R4 (refer to Figure 8) so that it will produce a plus 20 microamp output when a sample that is to be sorted is ~laced in the photocell viewing area. At plus 20 microamps ~he voltage at the bridge's output will be plus two volts. This positive two volts is applied to the input of the Schmitt trigger. When the input to the Schmitt trigger reaches plus two volts, it will fire. The qutput of the Schmitt trigger is fed to the amplifier. The amplifier amplifies tqe signal and applies it to both the invertor and the NOT switch (Sl). If the NAT switch is in the RED position the output of the amplifier is applied to the input of the NAND gate.
Note: If the sample to be sorted does not contain Red color ing, then the Red bridge is set to provide a 20 microamp output when a sample that is to be passed is placed in the NOT position. If the NOT switch is in the NOT position, with the bridge providing an

26.
output of plus two volts, the amplified signal is applied to the invertor which inverts the signal providing a NO output to the NAND gate. If the output of the bridge is less than plus two volts there will be a NO signal at the output of the amplifier. This NO output of the amplifier is inverted by the invertor, thereby providing a signal to the NAND gate via the NOT switch.
The RED lam? driver will only provide an output current to the RED lamp when there i.s a NO signal condition at the output of the invertor. Therefore the RED lamp is lit only when the RED bridge is producing an output of plus two volts, signifying that the sample being viewed contains the set quantity of red coloring.
The blue and green sections of the circuit function in a similar manner. The NAND gate will produce an output only when each of its three inputs have a signal applied to it. If one, two or all of the inputs is at a NO signal condition then the NAND gate will not produce an output. The output of the NAND gate is applied to the relay driver. The relay driver amplifies the signal causing the relay to energize. The cont~cts op the relay ,in turn light the AIR ON light and energize the solenoid air valve, which blows the sample off the conveyor belt. The meter monitors the output current of any one of the three color bridges, depending upon the poS~ition of the meter selector switch. The circuit values are so arranged that 10 microamps is equal to one volt, 20 microamps is equal to two volts, etc., when the meter sensitivity button is in its normal position. Depressing the meter sensitivity button multiplies the meter scale by a factor of two.
Detailed Circuit Operation
Bridge Circuits Red Bridge: The Red Bridge is composed of Pl, P2, Rl, 2, 3, and R4. Pl

27.
is the color sensing photocell and thus has a red filter placedin front of it, allowing it to measure only the Red rays that are reflected from the sample. P2 is the reflected light compensator photocell. It has no filter in front of it, therefore it measures the total light being reflected by the sample. P2's function is to automatically compensate the Bridge for the different reflectivities of the samples. R4 is a 25 turn trim potentiometer which sets the selectivity of R3. (The greatest selectivity is achieved when R3 is operating about mid-range.) R3 selects the amount of Red emission required from the sample to produce a 20 microamp @ two volts output. Rl and R2 are current limiting resistors to protect the photocells. The bridge power supply is connected in such a way (negative to the photocells' junction) that as the resistance of Pl decreases (due to red light rays striking Pl) the junction of Pl and R2 becomes more negative, thereby making the junction of Rl and R4 more positive with respect to ground. R3 forms a voltage divider with Pl, so that as the resistance of R3 is increased the voltage drop across it also increases thus reducing the amount of Red light required to produce a 20 microamp output at two volts. As the reflectivity of the sa~ple increases the resistance of P2 decreases, which in turn decreases the voltage at the junction of Rl and R4. In order for the bridge to produce the same output the junction of Pl and R2 must go even farther negative, which is what happens as the resistance of photocell Pl decreases due to the higher reflectivity of the sample. This action keeps the amount of red emission required for a given output the same even though the reflectivity of the samples varies over a wide range, R4 adjusts the amount of positive voltage applied to the output and thus the amount of current required through the Pl, R3 legs of the bridge to produce an output of two volts. (The less current the greater the selectivity).

~8.
Blue Bridge and Green Bridge: The Blue and Green Bridges' functions ~re I
identic~! to that of the Red Bridge.
SCHMITT TRIGPERS
--Red: The RED Schmitt Trigger is compo~ed of CRl, Ql, 2 and associated
resistors. Normally QZ is copducting, producing a voltage drop of 1.7 volts across the common emitters' resistor R9. This voltage dfOP in con~ junction ~ith R6 reverse biases Ql's base keeping it in its cutoff stat~. As long as the voltage applied to CRl is less than two volts, CRl will be reversed biased due to the 1.7 volt emitter potential of Ql and tme voltage drops of Ql's base to emitter junction, R5, anq the forward voltage drop required across CRl for it to conduct. When the output of the bridge reaches plus two volts CRl beco~s forward biased allowing current to flow
into the base of Ql. Ql then begins to conduct, this increases the volt
age drop across R7. As the voltage drop increases across R7 the forward bias of Q2 i~ decreased cau~ing Q2 to begin to turn off. This in turn lowers the voltage drop acrass R9, thus increasing the forward bias of Ql. This action is regenative which aids in increasing the speed of the switch ing cycle. Due to the higher resistance of R7 the voltage drop acros~ R9 with Ql conducting is 0.95 volts. Therefore CRl and Ql will now remain forward biased as long as the input to CRl is higher than 1.5 volts. As soon as the bridge output drops below 1.5 volts CRl becomes reversep biased, Ql starts to turq off, allowing Q2 to begin to cond~ct. As Q2 begins to conduct the ~ltage drop across R9 increases, causing the reverse bias to Ql and CRl to increase. This action is also regenative which aids in decreasing the cycling time.
Blue and Greene The Blue and Green Schmitt Trigger~ are identical to the Red Schmitt Trigger.

29.
AMPLIFIERS
~ The Red Amplifier is composed of CR2, 3, 4, 5, 6, Q~ and associated resistors. Rl5 and CR6 form a constant emitter bias for Q3 of about 0.4 volt. This emitter bias in conjunction with Rl3 provides a r~ve+se bia~ to Q3, qolding it off when Q2 is conducting. As long as Q2 conducts~ it dem~nds all of the current that Rll is able to supply, thus Rll is unable to supply the curren~ required to overcome the potential barriers of diodes CR2, 3, 4, and 5. However as soon as Q2 turns off, the current supplied by Rll will flow through diodes CR2, 3, 4, and 5. Q3 will now become forward biased and turn on. Due to transistor action the current from the Schmitt Trigger circuit is ampl~fied by Q3 to a sufficient level to drive both t~e Invertor and NAND Gate circuits.
Blue and Green: The Blue and Green Amplifiers' circuits are identical to the Red Amplifier.
INVERTORS
Red: The Red Invertor consists of CR7, 8, Q4 and associated resistors. Rl9 and CRS provide a constant emitter bias of approximately 0.4 volts for Q4. This emitter bias in conjunction with Rl7 provides a reverse base bias, keeping Q4 in its cutoff state while Q3 is conducting. As long as Q3 is conducting it demands all of the current that Rl4 is able to supply. Therefore Rl4 is unable to supply the current required to overcome the potential barrier of CR7 and thus forward bias Q4. However, as soon as Q3 turns off Rl4 is able to supply the required current for CR7 to conduct and to forward bias Q4. Q4 then turns on when Q3 is off and turns off when QJ is on, thus the si~nal is inverted. Due to transistor action Q4 also acts as an ampli-

30,
fier to provide enough current to drive both the Lamp Driver and the NAND Gate circuits.
Blue and Greeg: The Blue and Green Invertors are identical to the Red Invertor.
LAMP DRIVERS
Red; The Red Lamp Driver consists of CR9, QS, and associated resistors. Under a NO signal condition Q4 is conducting and therefore demands all of the current that Rl8 is able to supply. Since Rl8 is unable to supply current to QS, QS is in its cutoff state and DSl is unlit. When a signal is present Q4 is off, enabling Rl8 to supply the necessary bias to QS, to turn it on. QS then conducts, drawing current through DSl causing DSl (Red Lamp) to light. CR9 provides a small emitter bias for QS, which in conjunction with R21 insures that Q5 will remain off while Q4 is on.
Blue and Green: The Blue and Green Lamp Drivers' circuits are identical to the Red Lamp Driver cir~uit.
NAND Gate
The NAND Gate consists of CR22, 23, 24, 25, Qll and associated re sisters. Assuming that the three inputs to the NAND Gate are disconnected Qll is held in the cutoff state by the emitter bias supplied by R49 and CR25 in conjunction with base resistor R47. Now if the CR22 input is co~nected to Rl4 via Sl and provided that the Red Bridge is in the NO signal condition, CR22 will be forward biased allowing base current to flow in Qll, turning it on. If Q3 is tur~ed on by a signal from the Red

Brilige, Q3 will demand all the current thai: Rl4 is able to supply. Thh ~ction will reverse biaQ CR22 and Qll will turn off. The other inpu~ function in a similar matter, therefore, as long as any one of the inputs is at a positive potential Qll will conduct, thus inhiqiting the relay driver . from energizing the relay. The NOT Switc~es transfer the inputs of the NAND Gate to the invertors enabling the gate to pe inhibited by the presence of a color.
RELAY DRIVER The Relay Driver conststs of CR26, 27, 28, Ql2 and a$sociated resistors. The rel~y (Kl) is the collect9r load for Ql2. Normally Qll is conducting by a positive potential being present at one or more of the N~ Gate inputs. Qll then draws all the current that R48 is abl~ to supply, thus CR26 is reverse biased by the voltage drop across R48. ~ince CR26 is reverse biased, Ql2 is unable to obtain the necessary base drive to turn on, leaving Kl in its deenergized state. When the NAND Gate is enabled by the proper program being present at its inputs Qll will turn off, forward biasing CR26 and Ql2. Ql2 then turns on. The current flow through Ql2 energizes Kl. CR27 is shunted across Kl's coil to prevent damage to Ql2 from the high voltage spikes produced by the collapsing magnetic field of Kl.
Rf:LAY CIRCUIT The Relay (Kl) is energized by Ql2 as was previously discussed in section seven. Kl's contacts energize both the Air Valve's Solenoid and the Air On indicator DS5.
AIR VALVE The Air Valve is 110 VAC ope.rated solenoid valve energhed by the contacts of Kl.

I.
31,

32.
BRIDGE POWER SUPPLIES ~: The Red Bridge Power Supply cons!sts of CRlO, 11, 12, Tl, and associated components. The full-wave center tapped rectifier circuit composed of Tl, CRlO, and CRll supplies approximately 15 volts of pqlsa .. ting OC; This pulsating DC is smoothe9 out by Cl. Zener diode CR12 maintains a constant 10 volts drop across ~tself, which causes a constant 10 volts output to the load regardless of changes in the load current. R23 drops the remaining voltage potential between the unregulated and the regulated outputs. R23 also serves as an isolation resistor between capacitor Cl and capacitor C2. Capacitor C2 provides added filtering for the regul~ted output.
Blue and Green: The Blue and Green Bridges' Power Supplies are identical to the Red Bridge Power Supply.
MAIN POWER SUPPLY The Main Power Supply supplies 12 volt~ regulated DC for the operation of the logic cirquits. It c9nsists of CR46, 47, 48, 49, Ql8, 19, 20, T4; and associated components. Transformer T4 and rectifiers CR46 and CR47 form a full-wave center tapped rectifier circuit which supplie' unregulated pul~ating DC to filter capacitors C7 and C8. Capacitors C7 aqd C8 smooth out the unregulated DC. Transistor Ql8 serves as a well-filtered current source for zener diode CR48. Zener diode CR48 and temper~ture compensating diode CR49 provide a -12.4 volt reference for DC ampl~fier Ql9. Transistor Ql9 serves as a current amplifier for the series regulating transistor Q20. The emitter of Q20 maintains a constant potential of -12 volts with respect to point Z due to the emitter potential of -12.2 volts of Ql9. Ql9 1s emitter is held constant by the constant -12.4 volts potential applied to its base by CR48 and CR49. Capacitor ClO filters

33,
any remaining ripple present at the base of Q20 and also aida in lowering the output impedance of the supply.

34. APPENDIX 3 Color Sorter Farts List

SYMBOL
CR1, 13, 32 CR2, l, 4, 5, 7, 14, 15,
16' 17' 19' 26, 33' 34' 35, 36, 38 CR6, 8, 18, 20, 22, 23, 24, 25, 37, 38, 44, 45 CR9, 21, 27, 28, 40
CRlO, 11, 29, 30, 41, 42 CR12, 31, 43 CR46, 47 CR48 CR49 C1, 3, 5, 7, 8 C2, 4, 6, 10 C9 DS1 DS2 DS2 DS4, 5 F1 K1 Ml Pl, 3 P2, 4, 5, 6 Q1, 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 13, 14,
15' 16' 17 Ql8 Ql9 Q20 R1, 25, 55 R2, 26' 83 R3, 27, ~6 R4, 28 RS, 29' 58 R6, 52, 59 R7, 30, 60 R8, 31, 61 R9, 17, 32, 40, 47, 62, 70 R10, 33, 63 Rll, 34, 64, 79, 80 Rl2, 21, 35, 44, 65, 74 R13, 36, 66, Rl4, 37, 67 Rl5, 19, 38, 42, 49, 68, 72
Rl6, 39, 48, so, 69
Rl8, 41, 71 R20, 43, 73

DESCRIPTION
1N695A l.N461
lN270
1N530 1N536 1N3789B 1Nll24 1Nl524A 1N95 500mfd. @ SOV SOOmfd. @ lSV 200mfd. @ 15V Red Lamp Dialco 39L-6.3-971 Blue Lamp Dialco 39L-6.3-974 Green Lamp Dialco 39L-6.3-972 Neon Lamp Drake 105 Fuse 2A 3AG Relay P&B MB3D 12VDC Coil Meter 25-0-25 microamps Photocell Syl. 8346 Photocell Syl. 8345 2Nl302
2N1303 2Nl042 2Nl038-2 56 ohm lW 5% 47 ohm lW 5% lOK 10 Turn Pot. l.K 25 Turn Trim Pot . 43K ~w 5% 330K ~w 5% 150K ~W 5% 750K ~w 5%
13K ~w 5%
z4oK ~w 5% lOOK ~W 5% 5.6K ~w 5% 39K ~w s% 4.7K ~w 5% 2K ~w 5% 1.5K ~W 5% 510 ohm ~W 5% 27 ohm ~W 5%

SYMBOL
R22, 45, 75 R23, 53, 76 R.24, 54, 77 R46 R51 R57 R78 R81 R82 Sl, 2, 3 S4 S5 S6 Tl, 2, 3 T4

35,
DESCRIPTION
30 ohm 2W 5% 91 ohm 2W 5% 430 ohm lW 5% l.lK \W 5% ~.2K \W 5% 2K 25 Turn Trim Pot. 160 ohm \W 5% lK \W 5% 220 ohm \W 5% SPDT Troggle Switch 4 Position Selector Switch 1-C Push Button Switch SPST Troggle Switch Transformer Stancor TP-3 Transformer Stancor RT-201

3~ .

APPET:ID IX 4 Printed Circuit Card Connections

TERMINAL
A B
c
D E
F
H
J
X L M N
p
R
s
T
u
v
w
X y
z

CONNE(::TION

REP LOGIC CARD

Junction of P2 & Rl

11

of Rl & R4

"

of R2 & ~

11

of Pl, P2, & Bridge Neg. DC Supply

" of R3, R4, & Bridge Pos. DC Supply

RED Bridge Output to Sl

22 VAC from Tl
..
22 VAC from Tl CT of Tl To RED Lamp (DSl) GND.
+ 12VDC
NOT RED Out;put to Sl

BLUE LOGIC CARD

A

' Junction of p4 & R25

B

11

of R25 & R28

c

11

of R26 & R27

D

11

of Pl, P4, & Bridge Neg. DC Supply

~

11

of R2 7, R28, & Bridge Pos . DC Supply

F

BLUE Output to S2

H

J

K

L

22 VAC from T2

M

N

:f
R
s

T

u

22 VAC from T2

v

CT of T2

w

To BLUE Lamp

X

G\ld.

y

+ 12VDC

z

NOT BLUE Output to 82

Printed Circuit Card Connections cop't

TERMINAL I
A
B
C
.,
E
F
H J K
L
M N
p
R.
s
T
U V W X
Y
~

CO,NNECTIQN I

GREEN LOGIC CARD

Junction of P6 & R83

11

of R83 & R8 7

"

of ~5 & R56

"

of PS, P6, & Bridge Neg o DC Supply

11

of R56, ~.$ 7, & Bridge Po~ o DC Supply

GREEN Output to S3

22 VAC from T3

22 VAC from T3 CT of T3
To GREEN Lamp Gndo
+ 12 VDC
NOT GREEN output to S3

NAND

GATE 1

RELAY

DJUVEB. .~ I

RGUU,TOR

CARD I}

A

Prom Sl

B

From S2

c

From S3

1,)

E

F

H

J

K

Output to Kl

L

M

To Junction of CR46 & CR47 ~B on Power Supply Card)

N

p

To Ql9 Base (H on Power Supply Card)

R.
s

T
u
v
w

X

Gndo

y

+ 12 VDC

z

~8.

TERMINAL
A B
c
D E F H J K L M N p
R
s

Printed Circuit Card Connections con't

CONNEC'!ION
24 VAC from T4
.24 VAC from T4

POO'ER SUPPLY CAlU>

To Ju~c t ion of R~2 & C:,:t48 (Pof NAND GATE CARD)

.+ 12 VDC & CT of T4
Junction of CR46 & C~47 (To M on Nand Gate CaTd)
Gnd,

39 , APPENDIX 5 Cable Color Code for the Photo Cells

Wire Color
Blk Red
Blk Wht
Blk Grn
Blk Blu
Blk Yel
Blk Brn
Blk Orn
Red Wht
Red Grn

Function

P!n Number

il

I i

GRN Cell Output

1

11 11 and Reference Cell Common 2

GRN Reference Cell Output

3

Spare

4

Blu Cell Output

5

11 " Reference Cell Cormnon

6

Blu Refereqce Cell Outp4t

7

~pare

Red Cell Output

8

11 11 and Reference Cell Common 9

Red Reference Cell Output

10

Spare

Spare
II

II II

II II

40. APPENDIX 6 Cable Color Code for the Power .Supply

Wire Color
Blk Red
Blk Wht
Blk Grn
Blk Blu
Blk Yel
Blk Brn
Blk Orn
Red Wht
Red Grn

Function

Grn Bridge Line

II

II

II

Blu II

CT

II

II

II

Blu II

II

II

Line
II

Red II

II

II

II

II

Red II CT Spare

12 Volt Supply Line

II

II

II

II

12 Volt Supply CT Spare
110 Lin~ 110 Common
110 Relay GND

fin N!!!!!ber I
1
2
3 4
5
6
7 8
9 10
11 12
13 14
15 16
17 18

PART II
Survey of the Market for the Bell Mountain Silica
by
Dr. George R. Horton School of Business Administration
University of Georgia Athens, Georgia
Contents
Summary ----------------------------------------- 1 Introduction ------------------------------------ 2 Present Major Uses of Silica -----~-------------- 4
Rock Crystal -------------------------------- 4 Quartz gems and semiprecious stones ------- - - 6 Commercial silica --------------------------- 6 Sand and gravel ----------------------------- 17 Structural Stone ---------------------------- 18 Potential Uses of Silica ------------------------ 20 Prices --- --------------------------------------- 23 Characteristics of Bell Mountain Quartzite ------ 27 Bell Mountain Quartzite in the Market ----------- 28 Summary and Conclusions ------------------------- 36

1.
SUMMARY
Although the deposit of silica at Bell Mountain is being exploited on a limite9 scale, expansion of the market for this silica is unlikely at current price's (about $35. 00/ton).
Silica sand for the manufacture of glass brings an average of $3.00/ton. Silica used as flux brings a little over $2.00/ton; paving sand less than $1.00/ton; grinding and polishing silica $3.00/ton; silica for refractories about $13.00/ton.
The best potential market for the Bell Mountain silica is the cast stone trade, which offers a large market at prices around $30.00/ton. Thus the size of the market for the Bell Mountain silica depends, at present, on whether the price can be reduced about 1?%.
The prem~um price now asked by the Bell Mountain operator might be expected for silica carefully sorted according to color. A pilot-size color sorter has been deve~oped whose operation indicates that it can yield a satisfactory product at low cost. Still, there are uncertainties in going from a pilot-size operation to a full production operation. A production model will have to be built and operated before a conclusive statement can be made about operational cost. Because silica carefully sorted according to color has not been available before, the market for it is speculative.
A modest market exists for exceptionally pure silica for the manufacture of silica glass ($36.00/ton). The pilot-size sorter can turn out a high purity product, and might enable the Bell Mountain silica to tap this particular market.
Though there are possibilities for market expansion, a large market does not now exist for the Bell Mountain silica at current prices.

2.
INTRODUCTION
Bell Knob, a mountain in Towns County in North Georgia, is the site of a large deposit of high-grade quartzite. The development of a larger and better market for this rock will naturally redound to the advantage of the econumy of Towns and surrounding counties, and of the North Georgia mountain area in general. The purpose of this study is to inve~tigate the potentialities for such development.
Quartzite, one of many varieties of silica, might in theory be used in any of the hundreds of different applications of silica in industry. In practice, however, quartzite is restricted to particular uses by competition from other silica forms. This report will present the industrial uses of si~ica and will attempt to indicate the limits on the market for the Bell Mountain product, given the state of mining and industrial technology, pr~sent prices and transportation patterns, and ' present occurrences of various silica forms.
~he procedure employed in preparing this report has included written communication with approximately 400 firms which were considered ~ priori to be likely consumers of silica for a wide range of industrial and constructional purposes. Response to this communication ran at the unusually high level of 30 percent. Much of the information received from these firms confirmed conclusions deduced from a comparison of the chemical, physical, and mineralogical properties of Bell Mountain quartz with generally established industrial specifications. Indeed, the characteristics peculiar to the Bell Mountain product which would make it desirable to one purchaser are not necessarily the same as those sought by another purchaser: in each of many applications, the specifications are unique an~ the decision for use of a raw silica material ordinarily hinges upon evaluatiqn of a commercial sample.

3.
The extent of the potential market for this unusually high quality Georgia quartzite can only be speculated upon in very general terms since it is governed by many indeterminate factors.
At this point, it will be useful to arrange and clarify the various mineralogical and chemical terms which will be used throughout the report.
Two of the chemical elements predominate in the composition of the earth's crust: oxygen and silicon, constituting 47% and 28% respectively of the surface matter of this planet. A single compound of these two elements is one of the most abundant mineral constituents of the earth's crust: silicon dioxide, Si02 , which bears the chemical shorthand name silica. That silica is universally distributed is to be expected from the fact that it comprises such a large proportion of the material in the earth's crust.
Silica occurs in a free state in nature in many forms and degrees of purity, but these can be summed up as quartz and hydrous silica. The quartz family of minerals ranges from virtually pure crystalline quartz, through quartzite and sandstone to quartz sand. Hydrous silica (opal, flint, tripoli, diatomite, etc.) has a small and variable amount of water incorporated into the molecular structure. Together these forms of free silica constitute about 12% of the earth's substance; the only minerals more common than quartz are water and feldspar. The remaining silic~ on the earth, is combined in a ~arge number of compounds, some complex, of silica and the metallic elements; these are the silicate minerals: free silica and the silicates together have been estimated to constitute more than 90% of the earth's crust.
Rocks are aggregates of mineral substances. Virtually all the earth's ro~ks contain silica as their principal component. Many of the rocks are an aggregate of pure silica in the form of quartz grains or quartz sand. Sandstones are rocks consisting of grains of quartz or other siliceous minerals held together by some cementing material, as iron oxide, clay, calcite or

4.
silica. Sandstones vary in color depending largely upon the impurtties or non-quartz grains included in the rock, and upon the cementing agent.
Quartzite is metamorphosed sandstone; the grains of the sandstone have been so tightly cemented or fused that the rock fractures through the quartz grains rather than through the cement. Quartzite, is, then, considerably tougher than sandstone. It appears in a great variety of colors inasnruch as it is very rarely composed of pure silica but includes particles of minerals, other than quartz, which were present in the original sandstone.
In general use the term "silica" includes most of the varieties of quartz, sands, sandstones, and quartzites.
PRESENT MAJOR USES OF SILICA The physical and chemical properties of silica, together with its natural abundance make it very widely used in modern industry: it is hard, resistant to acids, transparent, and sturdy. Each of its multitude of forms has additional characteristics, sometimes desirable. On the basis of industrial uses, however, it is possible to classify the many forms of silica into a few well-defined categories: 1. Rock crystal. Quartz crystals of sufficiently high quality are used in a variety of electronic devices 1 as radio transmitters. Crystals of roughly the same quality are also used for making prisms, lenses, and other optical instruments: the principal difference between specifications for electronic grade and optical grade is that the former must be free from the physical property called electrical twinning, while the latter need not be; conversely, the latter must be water-clear, perfectly free from visible impurities, while the former need not be colorless. Virtually the same quality of crystal is required for fusing to make the pure silica glasses which are known as fused quartz, fused silica, or vitreous silica.

5.
Brazil is the principal source for natural quartz crystals of sufficiently high quality to be used for electronic, optical, and fusing purposes;
about 99 percent of U. s. imports of quartz crystals hav~ come from that
country. The U. S. is entirely dependent on imports for natural crystal for industrial use, although a few non-commercial small deposits of clear crystal have been found in various states, and although the Office of Mineral Exploration of the Department of the Interior subsidizes, through advances of 50 percent of approved costs, programs of exploration for quartz crystals.
Indeed, world reserves and production of natural ~rystals are negligible outside Brazil. Brazilian supplies can quite adequately meet ordinary commercial demands into the foreseeable future, but greater flexibility of supply from politically more stable sources to meet any unexpected demand, especially defense requirements, is greatly desirable. During World War II, the enormous jump in crystal consumption and the diffi~ulty of keeping up with wartime requirements very dramatically brought the problem of inflexible supply to the attention of U. S. officials; an extensiye research program was then launched to find some means of synthetically producing high grade quartz crystals. By 1958, the technology of synthetic quartz manufacture was sufficiently advanced that Sawyer Research Laboratories, Eastlake, Ohio, could undertake commercial production, while Western Electric began production for the Bell System at its plant in Haverhill, Massachusetts. Britain, Germany, and the Soviet Union, as well as the U. S., have done a significant amount of work on synthetic quartz crystal production.
There appears to be little doubt that synthetic quartz could become competitive with the natural product given sufficient incentive. U. S. Synthetic is largely produced from Brazilian lasca, which is natural cryst~l not good enough to meet industrial specifications. Thus the ~aw mat~rial from the cultured product comes from the same source as the natural product,

6.
a~d the U. s. supply of crystal is consequently little more flexible than it
has previously been. It is, however, technically feasible to produce syn~hetic quartz from raw material of much lower quality: low grade quartz crystals, and even quartzites. The utilization of such materials in syn~hetic production cannot be expected~ however, unless the superior ~nd cheap Brazilian material became for some reason unavailable. The~e is thus little likelihood that the Bell Mountain product will be able to compete in the market for cultured quartz raw material, except in the ~vent of political distress in Latip America. Even then, Arkansas and other states have deposits of rock crystal which would probably have the advantage.
2. Quartz gems and semiprecious stones. The jeweler~' trade has for centuries involved members of the quartz family; amethyst, smoky quartz, rose quartz, and quartz crystal are among the valuable ornamental stones of the quartz family and have all been found at Georgia ~ites. The market for gems and ornamental stones is so separate and different from the ind4strial quartz market that it need not be examined here.
3. Commercial silica. The chemical term "silica" has been ~ppropri ated by the' pommercial ~orld to cover mainly t~e lower gfades of silica that are used for industrial and chemict;~-1 purpos~s. "Commercial silica", in other words, refers to quartz other than crystal which is~ used for
building or ordinary sand and gravel purposes but !! used in industry,
especially in the chemical trades. The term encompasses various types of silica ra~ materials that have been segregated and refined by natural ~ro cesses into "nearly monomineralic deposits". In some cases these raw materials occur in nature as unconsolidated quartzose sand qr gravel and can be exploited with very little preparation and expense. More often they are found as sandstone conglomerate, quartzite, quartz-mica schist, or massive

7.
quartz; ~d must usually be crushed, washed, screened, and at times chemically treated before commercial uses.
Thus, whether in its original form, or broken, crushed, or ground, virtually all siliceous materials are called cqmmercial silica if they are used for any of a wide variety of industrial purposes.
Silica has a large range of industrial uses: as one writer ha~ put it, silica in one form or another "directly or indirectly touches practically every major manufacturing industry in our country, and it might be added that scientific research is continually discovering new uses for the substance.rr 1 It is especially desirable for many products which require abr~sion resistance, Ghemical inertness, increased compressive strength~ opacity, reduced shrinkage, resistance to elevative temperatures, increased tensile strength and toughness, water repellancy and resistance to weathering. Since in so many of these uses th~ various forms of silica are almost perfect substitutes for pne another, and since the mineral is so widely distributed and abundant in the earth's crust, prices are low and trade is governed by such factors as proximity to transportation or to markets. Most ground or crushed silica is s 0ld on sample, and specifications vary greatly depending upon the uses to ~Qich the buyer will put the product and what factors, such as impurities, mesh size, angularity or roundness of grain, etc., the buyer considers important. Tp summarize the uses of silica in industry, we can use a more or less standard format:
(a) Abrasive uses (b) Metallurgical uses (c) Refractory uses (d) Chemical uses (e) Glass and Ceramic uses (f) Filler and Extender uses Each of these in turn will be considered.

8.
(a) Abrasives: quartzite, more or less finely ground, is used for: 1. sand blasting; 2. sandpaper; 3. glass-grinding; 4. scouring and polishing soaps, pastes, powders, detergents, buffing compounds, etc. for woods, metals and teeth. 5 . Quartzite blocks are used for lining tube mills.
Of electric furnace abrasives, one of the most important is silicon carbide (carborundum) which requires the fusing of a mixture of carbon and high-grade silica. This extremely useful substance, which sells at prices comparable to those of natural diamond dust, is used in industries for grinding wheels and abrasive paper, high-temperature bricks, and as an insulator. Output in the immediate post-World War II period was about 60,000 tons annually, rising to double this figure in 1957-58. The preferred silica raw material is high-grade sand; i.e., pure glass sand. Equally pure crushed quartzite would presumably serve as adequately as the sands, but might necessitate some modification of the carborundum production techniques. This, however, is
'
beyond the scope of this paper. Similar considerations apply in other abrasive uses of ~ilica. (b) Metallurgy: Quartzite which can meet rigorous specifications is
used as a component in the preparation of silicon and silicon alloys and as a flux in the preparation of various materials, especially phosphorus. Silicon for chemical and electronic applications appears to be more commonly produced from sand or sandstone, but quartzite predominates in metallurgical silicon production. Silicon and silicon alloys were in 1958 being produced by thirteen firms for these purposes. Production for metallurgical use was about 515,000 short tons in that year.

9.

Firms: Hanna Furna~e Company

Buffalo, N.Y.

Hanna Nickel Smelting Company

Riddle, Oregon

Interlace Iron Company

Beverly, Ohio

Keokuk Electro-~etals Company

Keokuk, Iowa

.Vanadium Corporation of America

Wenatchee, Washington

Mpntana Ferro-Alloys Corporation

Woodstock, Tennessee

Ohio Ferro~Alloys Corporation

Brilliant, Ohio; Philo, Ohio, etc.

Pacific Northwest Alloys Corporation Mead, Washington

Pittsburgh Metallurgical Company

Charleston, S.C., Calvert City, Ky.

Tennessee Products and Chemicals

Rockwood, Tennessee

Tenn-Tex Alloys Cor~oration

Houston, Texas

Union Carbide Metals Company

Alloy, W. Va., Sheffield, Ala., etc.

Jackson Iron and Steel Company

Jackson, Ohio

I~ addition the following one dozen firms were, by 1960, producing high

quality silicon for electronic applications:

E. I. DuPont de Nemours & Company,Inc. Newport, Del. and Brevard, N. C.

International Metalloids, Inc.

Toa Alta, Puerto Rico

~agle-Picher Company

Miami, Okla.

Merck and Company, Inc.

Danville, Pennsylvania

Texas Instruments, Inc.

Houston, Texas

Sylvania Electric Products, Inc.

Towanda, Pennsylvania

Allegheny Electronic Chemicals Co.

Bradford, Pennsylvania

Trancoa Chemical Corporation

Reading, Massachusetts

Foote Minerals Cqmpany

Eston, Pennsylvania

Monsanto Chemical Company

St. Charles, Missouri

Dow Corning Corporation

Midland, Michigan

Kemet Company (Division of Union Carbide Corp.)

Cleveland, Ohio

10.

Other firms reportedly cons:i,dering silicon production at that time. included Kawecki Chemicals, Mallinckrodt Chemicals, General Electric, Philco, and Westinghouse.
Production of silicon for electronic purposes expanded greatly in the 1950's in conjunction with the rising output of transistors, diodes, and rectifiers. Prices ranged as high as $750 per pound, with an average probably in the neighborhood of $250 per pound. By 1960, however, the silicon industry was faced with ~evere internal problems deriving from Japanese competition in the production of semi-conductor devices, and techn9logical disputes over the degree of silicon purity requisite for electronic applications. It seems apparent that production of the highest grades of silicon will level off and decline as changing technology improves the competitive position of lower quality silicon and indeed of competing materials such as germanium, gallium, and organic semi-conductors. What impact these developments in the silicon producing and electronics industries will have upon their practices with regard to raw materials, including (potentially) Beil Mountain quartzit~, il'! difficult to estimate. Nevertheless, pres~nt general specifications would seem to indicate a strong demand over the foreseeable future for quartzite and other silica materials of high quality.
The lump size of quartzite generally used is between 1 and 6 inches, with the following specifications:

Silica (Si02)
Iron Oxide (Fe2o3)
Alumina (41203) Lime (CaO)
Magnesia (MgO)

Percent 98 min.
1 max. 1 max. 0.2 Max. 0.2 max.

11.

Arsenic and phosphorus should not be present, because of their toxic

qu~lities, even in trace amounts,

For use as a flux, quartzite of lower quality is acceptable. For

example, in the preparation of elemental phosphorus ~n electrical furnaces,

the lumps may be between 1 and 4 inches and meet the following specifications:

Percent

Silica (Si02)
Iron Oxide (Fe 2o3)
Alumin~ (Al2o3 )
Carbon Dioxide (C02) Lime (CaO)

98 min. 1.5 max. 1.5 max. 1.5 max. .2 max.

The principal sources of suitable quartzite for metallurgical purposes

1.n the U. S. have been Virginia, West Virginia, Tennessee, and North Carolina

ln the East; much quartzite is imported from Ontario where the deposits are

ideally situated for cheap ~xploitation and water transport to markets.

(c) Refractory: Fairly pure quartzite is one constituent of ganister

mix, which is composed of various quartzose substances and clay, and is used

to line and patch hot containers in the steel and foundry industries. The

variqus components of prepared ganister mixes are blended with regard to

pebble si~e and purity, and distributed dry to foundries and steel plants.

Silica firebricks of the best quality used to line furnaces are pre-

pared from rock meeting the following specifications:

Percent

Silica

97

min.

Alumina

1.0

max

Iron Oxide

3 - 1.3

Lime

.2 - 2.4

I.
12 .

Sodium Oxide
Potassium Oxide
Total lime, magnesia and alkalis

2 - 1.5

.2 - 1.5

2

max.

In.~957 and 1958, silica brick production was valued at $62 m. and $42 m., respectively. Pennsylvania, Alabama, and Wisconsin are principal U, S. sources of quartzite for these refractory purposes.
(d) Chemical: Quar~zite containing less than 0.4% alumina, 0.4% iron, 1.0% lime, and otherwise quite pure is used in the making of refractories for acid production. Similarly pure, virtually monomineralic quartzite is used in various chemical specialties; production of the requisite quality material is centered in the middle Appalachian states.
(e) Glass and Ceramics: Glass making uses sand, although quartzite Ould be perfectly suitable if it were as cheap and as pure as sand available at the present. Ground silica for use in the ceramic trades, as an ingredient of pottery, glazes, and enamels, must be of glass quality and very finely ground. Generally speaking, the distribution of sufficiently high quality materials ts limited, but the deposits coincide more or less with the presently densely pqpulated sections of the nation. The high cost of pulverization of massive quartzite puts it at a disadvantage in the competion for the glass sand trade.
In manufacturing glass, silica is a base material. Silica sands cons~itute from 52 percent to 65 2 percent of raw materials used in most ordinary glass and even up to 96 percent in certain special types. 3 Sands used in glass making must be uniformly pure, in most instances requiring at least 98 percent silica. One of the most objectionable impurities is iron, which tends to color the glass green and yellow. Silica with 0.3 percent iron oxide can be used in producing colored (green) glass. However, iron oxide

13.
content must be below 0.04 percent for most of the white varieties. 4 Alumina is also undesirable. Its presence makes glass less transparent.
In optical glass manufacturing, alumina of 0.1 percent is maximum. A higher alumina content silica can be used, however, in producing other types, in ma~y instances as high as 0.5 percent. Still other impurities which would rule certain silica materials out of glass production are titania and magnesia, if present in large quantities. Chemical specifications for silica used in various types of glass are shown in Table 1 below.

TABLE 1. Specifications for Chemical Composition of Glass Sands Percentage Composition ~ased on Ignited Sample.

1. First quality-optical glass

S(mi0i2n) 99.8

2. Second quality-flint glass

containers and tableware

98.5 0.5

3. Third quality-flint glass

95.0 4.0

4. Fourth quali~y-sheet glass,

rolled and polished plate

98.5 0.5

5. Fi~th quality-sheet glass,

rolled and polished plate

95.0 4.0

6. Sixth quality-green glass containers and window glass 98.0 0.5

7. Seventh quality-green glass 95.0 4.0

8. Eighth quality-amber glass 98.0 0.5

9. Ninth quality-amber glass

95.0 4.0

0.035 0.35
0.06
0.06
0.3 0.3 1.0 1.0

CaO + MgO
(max) 0.1
0.2 0.5
0.5
0.5
0.5 0.5 0.5 0.5

Source: Broadhurst, Sam D. -High-Silica Sand Resources of N.C., Raleigh, 1954' p. 5.

Bell Mountain quartzite can compete favorably with respect to purity as a raw material for glass making. With 99.96 percent silica content, Bell

14.
Mountain quartzite is quite suitable for first quality optical glass manufacturing. Impurities - alumina, iron oxide, etc. - are well below genera\ly specified minima. However, purity of raw material is on~y one, and at the moment not the most important, consideration to the glass maker. Natural silica sands are much cheaper, easier to handle, and are sufficiently abundant so that there would appear to be small chance for crushed quartzite to take much of this market.
Glass manufacturers are not in agreement as to the most effective grain sizes for glass sands. Quartz sand, to be accepted, should have uniform density and be free from trash. Extremely fine sands are generally undesirable because of dust losses which result in a reduction in material for processing. Fine sands also tend to block regenerators, necessitating more frequent close downs. Glass producers also often reject large grains because they slow down the fusing process by melting more. slowly. This, obviously, applies to crushed quartzite. It is generally agreed, however, that sand should pass through No. 20 sieve (0.8 mm.), and that the majority be held by No. 100 sieve (0.15 mm.).
There are large quantities of high-silica sand in Southeastern North
'
Carolina. Exploitation of these deposits could afford considerable competitian to Bell Mountain silica for some types of glass production. Most of these deposits are surficial and tend to be uniform in texture and composition.
In Georgia, also, sand and gravel combine to make one of the State's most important minerals. Sands are widely distributed throughout the State, being especially abundant in the northern part of the Coastal Plain district of southern Georgia. At one deposit in Gaillard, the Atlanta Sand and Supply Company mines sand of several size ranges, some of which might be suitable for window and bottle glass. The Libbey Glass Division of Owens-Illinois in Atlanta uses from 300 to 350 tons of sand per day for making glass. This

15.
sand is mined in southe~n Georgia near Thomasville. 5 There are still other
lower grade glass sand deposits near Macon , North Carolina sand occurrences have been divided into three geographic
and geo1og1. c reg1. ons. 6 One section, called "sandhills," is the northwestern edge of the Coastal Plain. This region is the most important source of silica sand in North Carolina. Much of the sand is sold for filler purposes and for general construction. Sand in the region i.s light tan to pale yellow and is fine to medium grained. Analyses of samplt sands from fine localities over the sandhills district averaged 97.1 percent Si02, 1.8 percent Al 203, 0.25
percent F'e 2o3 , 0.06 percent CaO plus MgO, and 0.67 percent ignition loss. 7
Gravel deposits of importance occur in Anson County. Chemical analyses of four washed samples are shown in Table 2.

Sample 1

TABLE 2 Si02 98.4

Al203 1. 02

Fe 2o3
0.17

2.

98.9

0.76

0.13

3

98.8

0.92

0.13

4

98.9

1.08

0.13

Source: Broadhurst, Sam D. - High-Silica Sand Resources of N. C., Raleigh, 1954, p. 14.

Another segment of the high-silica sand region of North Carolina is known as the Bay Sand District. The greatest concentration of high-silica sands in this region are in Bladen and Columbus counties. The deposit is exceptionally white and medium grained. Grain sizes vary from 0.125 mm. to 2 mm. Chemical analyses of white Bay sand are shown in Table 3. Sample 1 is a composite from 5 different locations in the deposit. Sample 2 is the whitest sand found in the deposit, and sample 3 is stained sand containing

16.

impurities. The volume of sands in the Bay distr.ict is so restric~ed that large-scale commercial development might not be feasible in many instances.

Sample 1

siq2 98.9

TABLE 3

A l 2 o3

Fe2o3

0.58

0.15

Ignition Loss
0.19

2

99.1

0.45

0.14

0.11

3

98.8

0.50

0.17

0.48

Source: Broadhurst, Sam D. -High-Silica Sand Resources of N.C., Raleigh, 1954, p. 17.

A third section can be logi~ally referred to as the Wilmington District, in which high-silica aand occurs in large volume. In the area just south of Wilmington, sands are medium to coarse in grain size and are very white near the surface, changing rapidly with depth to light tan. Northwest of Wilmington, the sand is light tan in color except for a very thin layer of white near the surface. Here the grains are medium sized, with about 95 percent of the particles measuring between 0.8 mm. and 0.175 mm.
Ch~~ical ~nd mineralogical characteristics of silica sands in Georgia and North Carolina, likely to be competitive with Bell Mountain silica, compare favorably with such sands in other regions of the eastern United States. Various tests indicate that these sands can be processed to meet rigid specifications in glass manufacturing.8 Costs of mining and processing glass sand are shown to be about $2.20 to $2.50 per ton in North Carolina in 1954.
In Georgia, $2.15 per ton was the average price of glass quality sand in 1960 inasfar as available estimates indicate. Many glass sands are unbiquitous throughout the middle-eastern United States so transportation costs are an important factor in determining the extent of the market.

17.
In the production of pottery, porcelain, and tile, large amounts of ground silica are used. In 1946, these uses accounted for about onehalf of the total value and tonnage of ground sandstone and quartzite produ~ed in the U. S. Moreover, ground silica employed in ceramic uses commanded a price
substantially higher than silica ground for glass, foundry, enamel~ or other
uses -- about $8.00 per ton. In grinding silica for ceramic use, pa~~age through a 140 mesh sieve seems to be the standard specification. Silica used in ceramics is also generally required to be very low in iron content, sometimes less than 0.05 percent. Amorphous silica in the form of ground flint or tripoli is often specified for pottery production.
(f) Filler and Extender: Finely ground quartzite and other finely ground silicas are used as inert extenders in paints; asbestos and a~phalt shingles; bituminous cements and asphalt pavings; asphalt tile; porcel~in; paper; rubber, hard rubber, molded and pressed goods, such ~s b~ttery boxes, phonograph records, etc.; in fertilizer, insecticides and pharmaceuticals. Quite obviously, specifications will vary with the use.
4. Sand and gravel. Some of the uses of these forms of quartz have already been discussed. In many very important uses, crushed quartzite is perfectly substitutable for quartzose sand and gravel; but for the most part~ the former is too expensive, especially when it must be finely crushed or ground. By far the most important uses of sand and gravel in terms of both tonnage and values, are in building and paving. Sands and gravels for such structural purposes are cheap and abundant.
Some special us~ of silica sands and gravels are scarcer and more valuable; glass and abrasive sands must meet the same specifications as quartzite used for these purposes. Filter sand and gravel for water and sewage works and for swimming pools are relatively expensive because they must meet high specifications as to size, uniformity of grain or pebble and so on. All in ~11, however,

18.

sand and gravel for most purposes are sufficiently abundant that they have

a relatively low value per ton. Thus transportation costs are extremely

significant in the industry, sometimes making up more than two thirds the

selling price.

Thirty-three companies produced sands and gravels in Georgia in 1960;

the outlook for sales is good as long as highway construction and other building

activities in the State continue. The 33 companies operate in 22 of the 159

counties; the leading companies were

(1) Atlanta Sand and Supply Company

Atlanta

(2) Bannockburn Sand Company

Valdosta

(3) Brown Brothers

Howard

(4) Daives Silica Mining Company

Thomasville

(5) Howard Sand Company

Howard

(6) Taylor Sand Company

Junction City

These companies supplied the bulk of the States' commercial sands.

With the abundance of sand and gravel reserves in Georgia and with an

extensive processing industry already in existence, it is unlikely that crushed

stone c~n effectively compete in the market for ordinary construction material.

5. Structural Stone. (Dimension stone and crushed stone for construc-

tion and cement purposes; crushed stone for chemical and metallurgical purposes

has been discussed above.) Dimension stone refers to blocks or slabs taken

from the original natural rock formations and cut to definite shapes and sizes

for commercial use. Quartzite blocks for certain refractory and lining

purposes in the chemical and metallurgical trades have been discussed above.

Under the heading of dimension stone here are included stone for building,

monumental, ornamental, paving, curbing and flagging purposes. Production of

stone for monumental purposes is often as great as that for building proper,

and far exceeds the latter in value. Quartzites are sparingly used in

19.
structural uses because of their hardness; but this same quality makes them desirable where there will be considerable subjection to abrasion, as on floors and steps. The use of any given type of stone for monumental purposes, and indeed for building purposes, greatly depends upon consumer tastes; the "brownstones" of New York, so very popular during the last centuries, are today considered passe.
The dimension stone industry appears to be what some economists call a "sick" industry. ':::'he materials are costly to quarry, prepare, transport, and install. Quite adequate substitute products are abundant, constantly increasing in number, and have already made inroads into stone sales. Steel, aluminum, and other metals; concrete and concrete blocks; glass and wood are continually eating away at the use of stone for building purposes. The paving-block industry is virtually dead; curbing and flagstones consumed only 300,000 tons of stone annually on the average in the U. S. 1954-1958. Consumption of building stone rose rapidly 1953-55 after being stagnant 1950-53; since 1955 it has hardly changed. Sales of memorial stone have hardly changed since 1948, averaging around $17-18 million. If architects and the public should shift their tastes in favor of stone, the industry may revive; but shifts in taste are unpredictable and slow at best. Even with some revival of the dimension stone industry, Georgia quartzite would face very severe competition from Georgia sandstone, marble and granite. However, in North Carolina and in Georgia there are several quarries for quartzite for building and flagstones.
Crushed stone is in many uses perfectly substitutable for gravel, as has been mentioned above. The following table shows for the year 1958 the more important uses of crushed and broken sandstone and quartzite along with those of sand and gravel.

20.

TABLE 4

Use

Sandstone or Quartzite

(thousand short tons)

1. Concrete and Roadstone

8,862

Sand

Gravel

.Building

100,323

94,181

Paving

98,155

309,579

2. Railroad Ballast

706

381

4,874

3. Fire or furnace sand

424

Fluxing stone

429

Refractory stone

.551

4. Rip rap

1,657

5. Cement

236

6. Other

12,043

40,981

31,182

Total sold or used by
producers in U. s.

24,484

240,264

439,816

Source: Mineral Facts and Problems, 1960, u. s. Bureau of Mines. "Stone,"
"Sand and Gravel."

POTENTIAL USES OF SILICA Any --discussion of potential uses of silica must be tentative: as the developments of the last decade in the use of silicon metal and silicon compounds have shown, technological advance may overnight change the entire market outlook for a raw material such as Bell Mountain quartzite. Silicon is now an important element in the booming space program and bids to become even more important. In other fields more indeterminancy prevails: the use of silica lenses and prisms in defense equipment, and the use of any raw silica material for these uses, depends entirely upon technological developments over a wide spectrum of products. It is not, however, only the possible development in the silicon industry which must be taken i.nto account; producers of germanium,

21.
gallium, and selenium, and mineral synthetics all of which are .to some degree competitive with silicon, can be expected to push forward the technology and adaptability of their respective materials. Potential m~rkets for silica in the space, electronics, chemical, and other high-technology industries are, in short, unpredictable.
The same is true for structural uses of quartzite, as was stated in the previous section. If consumer tastes should shift so as to favor the use of stone in general, and quartzite in particular for structural purposes, then building designs could be expected to reflect this change. Indeed, the architects themselves are probably the major determiners of public taste in building designs; and if architects should increase their u~e of quartzite alone or in combination with concrete, glass, or other structural media, the market for this stone will grow. Such changes in the thinking of architects and designers are completely unpredictable, although once a change has occurred, the historians may be able with the advantage of hindsight to see the logic of the change. In 1945, for example, it could hardly have been predicted that a national taste ;for "picture windows" would lead to ,~uch enormous use of glass in buildings. It is true, nevertheless, that architects are not governed entirely by personal and profe~sional ~rejudices but must also take account of costs~ avai~ability, and physical properties of their materials. It is imperative, then, that those engaged in the marketing of quartzite keep the member? of the architectural profession aware of and alive to the qualities of their product.
In recent years, the use of silica panels in buildings has increased ~ubstantially in the United States. It is entirely possible that some export market for the panels might be developed, despite the ubiquitous nature of silica. Stone of desirable color and required physical properties to be used in such panels is not universally distributed in large

22.
quantities. Moreover, U. S. producers may possess a comparativ,e advantage in the production of these panels due to their broader experience with the requisite techniques. For a number of years, Scotland and Scandinavia have quarried granite which has been shipped easily and economically to the countFies - France, England, Germany - on the western European plains where building stone has been scarce. The latter countries, of course, po~sess a large proportion of stone structures; this merely reflects the fact that stone is relatively less scarce than wood~ the other conventional structural material. The possibilities of sh~pping silica panels for use in the building trades in western Europe should be investigated further; to this end the services of the U. S. Department of Commerce Field Offices (Atlanta, Savannah, Greensboro, Charleston, Richmond, and Jacksonville) and of the various State Ports Authorities should be utili~ed. The present is an unusually favorable time for businessmen to inquire into the development of overseas markets, since the major charge of the U. S. Department of Commerce in the present administration is to expand U. S. exports and assist in re~es~ablishing equilibrium in the nation's balance of international payments, The Consular Service ,~nd the Bureau of International Commerce together provipe facilities for trade fairs at which American products may be demonstrated to potential foreign consumers; in some major cities, such as Tokyo and London, permanent U. S. trade centers are maintained. Industrial trade missions, consisting of businessmen in a given field, are extended every facility in making contact with the potential foreign customer. In recent weekp, there have been inquiries about the purchase of U. S. abrasives, insulation materials, pottery, floor and wall tiles, and refractory materials from such cp~ntrie~ as France, Germany, Pakistan, and others, shown in International Commerce, the weekly publication of the Bureau of International Commerpe,
Another possible new use of silica is in the livestock feed trade,

23.
especially in the poultry feed industry. Ground $ilica could be used as grit in such feeds. Interviews with poultry feed manufacturers indicate that coarse crushed granite and fine granite grit and marble chips are presently being used in large quantities. One large poultry feed manufacturer indicated that.cost was a prime factor in determining the grit material. He is presently purchasing both the coarse and fine granite grit from Stone Mountain, Georgia, in 80 pound bags at $8.00 per ton F.O.B. Such prices are considerably below those currently quoted for Bell Mountain silica F.O.B. Murphy, N. C. However, economics of scale in mining operations might permit Bell Mountain quartz to become competitive in this area as new markets for silica are developed elsewhere. This possibility, of course, depends upon mining technology and decreasing unit costs as output is expanded.
PRICES Prices for silica vary over a wide range with quality. Quartz crystal of electronic grade has run as high as $10.70 per pound in 1946. In the late 1950's quartz crystal prices fell to about $1.50 per pound. This, however, is the highest of all grades of silica. Prices of industrial and structural silica materials are much lower. Glass sand prices in 1958 averaged about $3.00 per ton; sand for furnace use, a little over $2.00 per ton; paving sand, less than $1.00 per ton; and grinding and polishing sands, about $3.30 per ton. In the same year, crushed sandstone and quartzite averaged less than $2.00 per ton in all uses; for refractory uses it averaged around $13.00 per ton; in cement, about $2.00 per ton; and for concrete and road stone purposes, only a little over $1.00. This wide variation in prices is not entirely due to variations in physical and chemical properties of the various forms of silica; it is in large part due to the extremely competitive conditions to be found in many of the branches of industry in which silica is used. In the uses for which prices are very low, it is usually possible to find a

24.
host of substitute materials pressing on the market, making demand more elastic through the relevant price range. Prices for crushed stone have hardly changed over the past three decades of general inflation. Prices of those particular types of crushed stone which can be used for refractory purposes, by contrast, have tripled over the last decade.
These statements may be clarified with the aid of some tools of elementary economic analysis. In the charts below, prices are measured along the axis of ordinates (i.e., y or vertical axis) while quantities per unit of time such as week, month, or year are measured along the abscissa (i.e., x or horizontal axis). In the first graph, the quantities of product which consumers would be able and willing to buy at each of various possible prices are shown by the line DD. This line reflects consumer attitudes at a given point in time, assuming that the prices of other products which consumers regard as adequate substitutes are held constant. It is assumed in the first graph that there are many substitute products available at the same prices
as those represented on they ax is. Thus, if the price of product A is relativ~ly low, much :Jf :it will be bought, whereas, if its price were at any
of the successively higher levels, successively smaller quantities would be consumed.
p
-D -----------------n
~---------------------------- Q/uT

25.
In the second chart, which is drawn to the same scale and in the same manner, it is assumed that there are very few substitutes for product A available through the relevant price range.
p
D' Q/uT
It still remains true that sales of A will be greater at low prices than at high since it is assumed that consumers with limited financial resources will tend to use more of ordinary products at lower prices than at higher; but the lack of adequate substitutes at prices regarded as reasonable implies that this schedule of quantities demanded at various prices D'D' will be steeper than DD in the first chart.
The aggregate demand for quartzite for use in high grade glass manufacture, in the making of first-grade silica fire bricks and other refractory
',
materials, and in the metallurgical industries, is probably closer to that pictured in the second chart than to the situation depicted in the first chart. The demand for any particular commercial brand of quartzite for these purposes, however, may be more like that shown in the first chart since by definition all commercial brands of equally good quartzite are substitutes for one another in these uses. In such a situation, a price reproduction by any one firm would result in a substantial increase i.n sales if competitors do not follow suit. Conversely, in this situation if a producer's prices are higher than those of his competitors, his sales will be substantially smaller than if he were meeting their prices. In fact, he may price his product completely out of a market where close substitutes are available.

26.
In uses of silica other than those specified in the preceding paragraph, the adequate substitutes for quartzite are much more numerous; and in some cases, these substitutes are. enormously abundant and quite cheap. In tltese uses, then, thE: aggregate: demand for quartzite and the demand for any individual brand of q.1arr:zi.!:.e are both likely to resemble the case shown in chart 1. All together thi:E: analysis is intended only to demonstrate the vital necessjty for any p:codv.c.er to remai,n constantly in touch with the market price situation and periodic gyrations in the prices being offered to his customers not only by other producers of the same silica raw material but also by producers of subst i.t.utf'. materials. It should also be clear from this analysis that a decrease in pr.ice may bring additional purchasers into the market, some of whom are now using substitute silica materials and possibly some new buyers who are not using silica at all.
The price that consumers are willing to pay is not the only important consideration for the firm. Its product must command a price which at least covers all costs, especially in the long run. In this connection, however, it should be remember.sd trtat production costs per unit for most products varies with the scale of output so that no producer should ever take his current per unit costs as unchanging with output unless he has bad experience to the contrary.
Transportation costs, as well as the availability of substitutes and the variations of quality, substantially affect the price which silica can command. One important possibility for market extension lies in delivered final price reduction through special transportation rates based upon multiplecar shipments. Southern Ra i lway, one of two lines serving Murphy, N.C., the point from which Bell Mountain products are shipped, has alrefldy reduced rates on some commodities moving in multiple-car shipments. The'se savings in transport costs could permit products to become competitive in areas con-

27.

sidered too distant under the present rate structure. This would be especially brue where demand for the Bell Mountain product is highly price ~lastic because pf close substitutes.
Because of the extreme variability in prices of silica products, it is no~ at all unusual for one consumer to regard as outrageously high a price which is readily acceptable by another. This will be seen below when the responses of various potential consumers to quotations of the Bell ~ountain product are considered.

CHARACTERISTICS OF BELL MOUNTAIN QUARTZITE The deposit at Bell Mountain is of unusually high chemical and physical qualtty. A chemical analysis furnished by the distributors is shown below.

SiOz
At 2o3 Fe 2o3
Total Alk.
Ignition Loss
Moi&ture

ANALYSES OF BELL MOUNTAIN QUARTZ

Gray

Mixed

Pink

99.2

99.1

98.8

0.18

0.33

0.28

0.07

0.23

0.57

0.10

0.19

0.16

0.42

0.05

0,01

0.00

0.00

0.00

99.97

99.90

99.82

White 99,96
0.009 0.001 0.000 0.000 0.000 99.970

Pri~es for the various shades other than white are $40.00 per ton F.O.B. Murphy, N. C. bagged in 100 pound bags. A bulk carload discount pf $2.50 per ton is allowed both on this price and on the $36.00 per ton price of the snow white variety. Terms are the usual commercial terms of 2 percent discount; net 10 days. It is readily apparent from the chemical analysis above that Bell Mpuntain quartzite is in a favorable competitive position so far as purity is concerned. With 99.96 per cent silica content, Bell Mountain quartzite is quite satisfactory for first quality optical glass manufacturing.

28 .
Alumina content, 0.009 percent, is well below the manufacturer's specified minimum of 0.1 per cent for high quality optical glass production; and iron
oxide, Fe 2o3 , is almost non-existent in the snow white quartz.
In the manufacturing of fused-quartz chemical apparatus such as tubes,
.
crucibles, dishes, and other crystal materials, very pure crushed quartzite is the preferred material. In making silica fire bricks and in the metallurgical trades, pure forms of silica, including quartzites, are needed. In these and ot.her cases in which chemical purity is important, Bell Mountain quartzite is in a favorable competitive position. It appears, on the basis Qf chemical characteristics, that the greatest potentials for Bell Mountain quartzite, as a form of commercial silica, lie in metallurgical, chemical and refractqry fSes to~ether with production of ~xtremely high-quality glass.
The physical characteristics of Bell Mountain quartzite, including especially its color, appear to be such as to favor it in the market place. The material is tough and d~rable, qualities which are highly desirable for many construction purposes. The various tints of the Bell Mountain product permit a pleasing aesthetic effect which together with its toughness and durability make it competitive with marble and granite for structural purposes. These same qualities may be appealing to the makers of livestock feeds and inert extenders for paints and plactics; color has been repeatedly dempnstrated to be a most important factor in consumer motivation to purchase.
BELL MOUNTAIN QUARTZITE IN THE MARKET During discussions incident to the initiation of this project it became clear that one of the principal potential markets for Bell Mountain quartzite was to be found among manufacturers of cast silica panels for building purposes. A list of 109 such firms across the United States and Canada was developed. These firms were subsequently contacted and invited

29.
to express their reaction to the Bell Mountain quartzite. The companies
were also provided with a chemical analysis and probable prices. The
rate of response to this solicitation of opinions was fairly typical, about
25 percent. A considerable proportion of the responding companies stated
that the selection of basic raw materials used in casting architectural con-
crete products is made by the architects involved and for specific projects;
this necessitated a second round of conununication, this time with architects.
A great deal of other information was elicited from the aggregate panel
producers. Their reactions were curiously mixed; practically all indicated
an interest in samples, but some stated an unwillingness to buy at current
prices:
We are currently receLvLng 50 tons per week of a very nice opaque white quartz, bagged in 100 pound jute bags . . . at $36.40 per ton so you can see that your prices are not attractive to us here ... I would like to receive small two or three ounce samples.
From Pennsylvania:
We would not be willing to use any of the products at the indicated prices unless they were of exceptional quality. We are currently buying the pink and white quartz for $33.00 per ton.
From Tennessee:
We would not be interested in purchasing the product at the price you have stated . Our usage per month is about 150,000200,000 pounds.
From New York:
The prices shown on your analysis sheet tend to offset (our interest in the material). Unless there is a substantial reduction . we would not be too willing to purchase.
On the other hand, from Texas:
We normally purchase 1500 to 2500 tons of crushed quartz from sources scattered from Colorado to Georgia. Your prices seem to be in line.

I.
30.

And similarly, from Missouri:
Our source of supply has been Colorado and the prices being paid are approximately those quoted.

Some firms indicated that they are not currently in the market ior

crus~ed quartz despite their being cast stone product companies. Many also

indicated that they might enter the market although none specified the

conditions under which they would do so.

The general response, however, was similar to the following from Georgia,

South Carolina, New York, and Texas:

It is impossible for us to tell you the quantities that we would purchase, It would all depend upon future orders, depending upon the finish and color of our products as selected by the architects.

We only buy material that has been approved by an architect or owner for use on a specific job.

We use this type of material . . . selected

by the owner or architect

the prices

you show are generally in line.

Our reqt!irements are based on jobs we obtain.

It wo:.tld be impossible for us to use this product unless this material was specified.

In view of this response, it was believed imperative that leading architectural firms in at least the southeastern states should be asked for their opinion of the Bell Mountain quartzite, The Secretaries of State for various southeastern states were asked to provide their rosters of registered architects and about 175 architects were asked to conunent.
Meanwhile, the U, S. Bureau of Mines provided its list of buyers of silica raw materials, most of which were glass, chemical, and metallurgical manufacturers. Sixty-eight such firms were contacted and provided with

31.
chemical analysis sheets and price information on Bell Mountain quartz. The r~spon.se was unusually high, about 35 percent, but reaction was orice again qui.te varied. Many chemical and glass companies indicated no interest in the material. In addition, most of the glass companies indicated that this crushed quartz is extremely high-priced as compared with the sands they are currently using. West coast firms exhibited a complete lack of interest since transportation costs would be ~9 high for the distance involved.
Practically all of these major users of silica raw materials have plants or suppliers located sufficiently close to abundant supplies of high-silica sands that they would not be interested in the product. The exceptions, however, are very important. One of the ~ation's larger glass manufact~rers stated an interest in using white quartz for certain special purposes:
Our requirements would be in the neighborhood of 1000 tons annually . . . $36.00 per ton would be in line for a bagged product F .O ..B. Murphy, N. C.
A large middle western distributor of laboratory supplies and chemicals expressed an interest in large quantities of the white quartz. One major electrical products firm requested samples. Finally, a Pennsylvania firm, using extremely high-purity Brazilian quartz wrote that it ~ight be able to substitute the north Georgia substance. This company said that the main reason for using Brazilian quartz is its particle size, purity and the minimum amount of surface contamination. The products of this firm include quartz crystal blanks, cultured quartz, and precision cutting and lapping machinery. In producing some of these items, the most detrimental element is alumina, Al203, which is quite low in the Bell Mountain quartzite.
One large steel producer stated that some of its eastern plants use silica in various forms but added that silica deposits in Pennsylvania, New Jersey, and New York were sufficient in quantity and quality for their use. A manufacturer of cleanser products in the easte~n U. S. indicatei that it

32.
uses "considerable" quantities of silica in its operations but at .a much lower cost than the quoted prices for Bell Mountain quartzite. Still another producer of flint glass expressed an interest in the North Georgia product if it could be offered in the form of washed and dried silica sand rather than as cryst~l. In this instance, the quoted prices apparently would be acceptable. However, one of the nation's larger producers of glass wrote that its research and development department examined the analysis sheet and concluded that "the quality is too poor for our use and the cost is high."
Another very large producer of food products and cleansers indicated that it uses quartzose materials in the form of sand and flour, but that it could not use the Bell Mountain product at the prices quoted. This firm is a large purchaser of silica which can be seen in estimated quantities consumed per year by six of its plants over the nation. These estimates are:

Material Silica flour Silica flour Silica flour Silica flour Silica sand Silica sand

Plant Location New York Missouri California Canada New York Kansas

Estimated Usage 21,500 tons 46,500 tons 12,700 tons 4,700 tons 8,000 tons 9,500 tons

Specifications for the above firm include 98 percent minimum silica and 0.06 percent maximum iron oxide. Bell Mountain quartzite is well above these chemical requirements.
Responses from the architectural firms which had been contacted as a result of the experience with the initial list of panel firms began to filter in; architects in eastern states from Rhode Island to Texas had been invited to express their willingness to use the North Georgia quartzite at

33 .
prices indicated. As was to have been anticipated, most of the replies were
framed in terms of an interest in using the product and a desire to see
samples but an inability to make specific commitments or even to estimate
quantities needed since all such decisions by designers and engineers are
conventi.onally made in conjunction with the owner.
The following comments are typical:
We do not purchase any materials. We do, however, specify aggregates by description.
We, of course, are always interested in anything new and anything which is an improvement.
Both of the above comments carne from Georgia designers, as did the following:
Samples of the product which you discuss (should be sent so that it can be estimated) whether or not they would be acceptable for use in our construction program.
The following remarks carne from firms in Virginia:
We are familiar with high grade silica applications in the buildi~g industry. We recently considered the .use of a very white variety of quartz for the facing panels of a large building. The material considered was a massive, sugary textured, extremely white quartz.
Although a number of considerations usually influence the final selection as to the use of this type of material, the high cost plus combat . . . . (a comparable material) cannot be delivered here for appreciably under $40.00 per ton in the 3/8" to 3/411 size range. White to gray-white (with some iron discoloration) crushed quartz gravel is available here for less than $6.00 per ton.
Our reaction to a product such as yours would be favorable from an esthetic point of view. Ther~ undoubtedly will be occasions when we will recommend and/or specify a product cornparable to the Bell Mountain silica but it is very difficult to indicate the quantity which we might specify. Normally we do not purchase any such material direct.
(

~.
We would like to request . . . . a sample.
There is a need in the building field for this type of material.
From Pennsylvania:
We have several jobs that are now in the design stage in which we are using precast members . . .
A firm of architects and engineers in Massachusetts expressed the following
septiments which nicely summarize the typical reaction:
We would like to see a sample of the commercially available silica mentioned in your letter of October 17, 1963. We have no way of predicting our use of the material. If we like it, if we have a building where cast stone panels seem appropriate, and if we are convinced that the cast stone manufacturer can make a product comparable in durability to marble or other natural stones for considerable less money, then we woulq consider it. As you can see, any prediction based on tonnage or square feet would be wildest conjecture.
Tpe evidence shown above would support the conclusion that tpe needs
of architects should be kept in mind by the processor~ of Bell Mountain
quartzite. Advertising efforts should be directed, within the constraints
.
q ~osts and circulation, to those media likely to reach members of this
profe~sion, An investment in a small leaflet or brochure describing the
propertie~ of the quartzite and citing cases in which it has been success-
fully used for structural purposes in aggregate panels should be worthwhile,
although, of course, any such decision concerning the allocation of funds
for advertising must be made by management in the context of circumstances
with whi~h only they can be familiar.
Breliminary investigations in the literature and conversations with
the Bureau of Mines personnel and others competent in the field had shown

35.
the desirability of extending the research beyond the three categories of potentially interested parties already discussed: aggregate panel manufacturers, architects, and major buyers of silica raw materials in heavy industry. Consequently, it was decided to pursue the following procedure for further research . . The Bureau of Mines had provided a list of uses for ground quartzite and sandstone. This list was employed in conjunction with Standard and Poor's 1963 Register of Corporations, Directors and Exec~ t ives to obtain the names of firms other than those earlier identified from the Maun~y and Bureau of Mines lists and the architects registers, and likely to have some interest in silica. This collection of firms included companies in such industries as the following: paper; roofing and flooring; plywoods and plastics; paints, porcelain, china and whiteware; tile, mosaic, and terrazzo producers; and acoustical insulating and fireproofing. It was reasoned ~ pfiori that many of these firms would not in the least be interested in purchasing crushed quartzite; but it was considered important to obtain spme confirmation of this impression: negative information is nonetheless information. It was also considered desirable to make the scope of inquiry as broad as time and funds permitted. Of the thousands of firms which might have been contacted in this phase of the study, seventy-five were selected; the inquiry to these firms was accompanied by an addressed post card for reply, this relatively expensive device being considered justified by the nature of these firms and the unlikelihood of their otherwise responding to an inquiry concerning a substance in which they have no vital interest. This techpique was successful in that over half of the firms had at the date of this writing made reply. As anticipated, many of the respondents showed little iqterest in Bell Mountain quartz. However, much useful information was gleaned concerning the price of silica substitutes in various parts of the country, as is shown in the following excerpts.

36.
A North Carolina roofing company commented as follows: We do not use silica. We do use white marble for surfacing of built up roofs, anywhere from 5 to 15 carloads per year.
A Delaware roofer uses mica at the rate of about 800 tons per year, as does a roofing ~ompany in Michigan. The tile companies, like the asphalt producers, insulation producers, and various others, used silica sands in great quantities but at prices as low as $1.00 per ton. The same is true of porcelain producers. A metal works company in the Middle West indicated purchases of about 80,000 pounds of silica per year at a price of $21.00 per ton delivered, while another in Connecticut pays $12.00 per ton for a material considered by them comparable for their purposes to Bell Mountain quartz. A plastics manufacturer indicates that he has used small amounts of various white stones.
Pulp and paper companies, like specialty glass concerns, use sand at low prices. One porcelain company buys its porcelain raw materials from Du Pont and other chemical companies. He remarks that these raw material substances "undoubtedly contain silica," but it is likely that the silica form is sand.
SUMMARY AND CONCLUSIONS
Silica is among the most abundant of all materials, and occurs in large number of forms, resulting in its being readily adaptable to wide variety of industrial functions.
As earlier noted, any discussion of potential uses of silica must be tentative and carried on subject to reservations concerning the rate of technological change, discoveries of new deposits, and the tastes of consumers, including government and defense contractors.
The place of Bell Mountain quartzite in this family of minerals and

37.
its relative market position cannot therefore be stated simply and . summarily. However, a market does ex~st for this product in ~he building industry at pri~es around $30.00 per ton. Careful development of this potential market through contacts with architects woulp provide the most profitable outlet for the Bell ~o~ntain product, Investors should, where feasible, deal directly with ~rchitect~ since the latter often make recommendations concerning specific products used in their projects.
At current pr~ces, the prospects for expansion of the Bell Mountain silica mar~et in the glass (except high-grade glass), chemical, and cleanser industries ~s far from bright. As earlier iqdicated, many firms in these industries stated that they could obtain silica sands in great quantities at prices, in some instances, as low as $1.00 per ton. The metallurgical trades could also be a promieing field for development, although in this case, as also in the case of the electronics industry, all developments hinge upon technological ad-
vance~.
New ~arkets could conceivably be peveloped in the livestock feed industry and in the monumental stone trades. In connection with the latter, colored panels of quartzite may well be preferred over marble or granite by some custom~rs. The possibilities of an exp9rt market for crushed, broken, and cast quartzite should not be overlooked since in the decade prior to 1962 approximately 400,000 cubic feet of building and moqumental stone, valued at an average of $1.1 million per year was exported from the United States, while exports of crushed stone, other than limestone, averaged a little more than 150,000 ~hart tons per year of an average value in excess of $2.5 million.
Deposits at Bell Mountain are presently being profitably exploited and the preponderanc~ of evidence gathered in the market survey indicates that the market can be extended. For the firm presently min~ng quartzite at Bell Mountain and for any other mining companies contemplating operations at this

38
site, the greatest promise is with the architects and the most profitable market is in cast stone panels for construction. Investors, including the present developers of the deposit, should, and unquestionably will, realize that the extremely vigorous competition from technologically substitutable products necessitates aggressive promotion of Bell Mountain quartzite if operations are to be extended at a profit. The most desirable fashion in which to extend production for purposes other than construction is through advance contractual arrangements, if these are possible; large industrial buyers should indicate a willingness to buy before production is increased. Selling the material, in other words, should logically precede its production. Further, inventories should be carefully controlled and limited to standardized items. In the ordinary course of business, such advance commitments by buyers are not traditional, but this century has witnessed a continuous extension of "cost-plus" contracts and similar devices, particularly in connection with government, defense, and advanced technology projects.
An incidental, but interesting, result of this inquiry was the discovery, somewhat surprising in view of the great antiquity of the stone i~dustries, that rel.~tively little research on the marketing of silica raw materials has been done at all, and hardly any in recent years. Correspondence with the schools of mines of such important mining states as Montana, Colorado, New Mexico, and Michigan failed to reveal any marketing studies; the work at these institutions has been almost entirely of a highly technological variety. A similar pattern prevails, although to a much less pronounced extent, i.n the work of the Bureau of Mines of the Department of the Interior. 'The latter organizations, of course, have access to the incredibly vast statistical resources of the entire Federal Government and have made. good use of some information on purchasers, prices, uses, substitutes for, exports, and imports of stone.

39.
. It may be concluded then that the following recommendation.s are in order
for firms already in operation or for prospectiv~ investors: 1. Operations at nell Mountain can be expanded at a profit, especially
for the building industry. Advertising funds should be directed toward professipnal architectura~ jqurnals and the trade journals in metallurgy, electronics, and crystal and flint glass manufacture. Direct mail solicitation should always be accompanied by samples, as well as by a chemical and physical analysis, and a statement of mesh sizes available. The testimonials of satisfied customers in the same line of endeavor as the potential customer are in this, as in all march~ndising situations, one of the best forms of advertisement;
2. The resources of the Federal Governm~nt should be utili~ed to the fullest extent in investigating the possibility of development of an overseas market. Similarly, if it is geologically probable that even higher quality rock, and especially pure crystalline quartz, can be found iri the vicinity of the presently exploited deposits, then the program of the Office of Mineral Exploration for subsidizing exploration costs should be investigated;
3. -The possibility of developing a market for mine chips, as the scale of mining operations is increased, in the poultry feed industry should be examined at regular intervals;
4. The monumental stone industry should be kept in mind as a possible purchaser of quartz of all colors. Since Georgia is one of the more important states in the prod~ction of monumental stones~ keeping in close association with developments in that industry should be relatively easily accomplished;
5. Pricing policies should be the subject of constant review and based upon as much information as is available conc~rning the price of and consumer tastes for substitutes; and

40.
6. Technological developments in the propuction of silicon should be closely watched; and contact with the firms producing silicon should be constantly maintained so that it will be known if and when quartzite becomes a preferable raw material for which consurr,ing firms might make advance contractual commitments.
The determination of the extent and profitability of expanding operations at Bell Mountain will necessitate continuJ.ng and close contact between marketing agents and mining engineers of ~he companies involved.

41.

POOTNqTES

1. Dake, H. C., Quartz Family Minerals~ (New York: McGraw-~ill, 1938),

p. 123.

!

2 . Burchard, E. F., Glass Sand, O~her Sand and Grav~l: Mineral Resources

of the United Stat!S for 1911, Part 2, pp. 594-595.

l

I

3. Shreve, R.N., The Chemical Process Iqdutries, (New York: McGraw~Hill,

1945), P 219,

)

I

4. Broadhurst, Sam D., Hish~~ilica Sand Repources of North Carolina,

Raleigh, 1954.

I

I 1

I

5. Whit1ach, George I., Qeorgia 1 s Mineral &rsources, ~t1anta: Georgia Institute of T~chnology, 1962,p, 70.

6. Broadhurst, op. cit., p. 7.

7. Ibid., p. 14.

8. See Broadhurst, pp. 29-33 and Whit1ach, p. 71.

42.
LIST OF REFERENCES
American Institute of Mining Engineers, Industrial Minerals and Rocks, 3rd edition, New York, 1960.
Broadhurst, Sam D., High-Silica Materials in North Carolina, Information Circular, N. C. Dept. o Conservation and Development, Raleigh, 1948.
Broadhurst, Sam D., High-Silica Sand Resources of North Carolina, Information Circular 11, N. C. Dept. of Conservation, Raleigh, 1954.
Chemical Analyses, price lists, and commercial specifications supplied by Mauney Distributing Company, Raleigh, N. C.
Councill, Richard J., Miscellaneous Commercial Rocks Qf North Carolina, Information Circular 13, N. C. Dept. of Conservation and Development, Raleigh, 1955.
Dake, H. C., et. al., Quartz Family Minerals. New York: McGraw-Hill Book Company, 1938.
Georgia Department of Mines, Directory of Georgia Mineral Producers, 11th edition, Atlanta, 1961.
Iadoo, Raymond B. and W. M. Myers, Non-Metallic Minerals, second edition. New York: McGraw-Hill Book Company, 1951.
Johnstone and Johnstone, Minerals, second edition. New York: John Wiley and Sons, Inc., 1942.
McGraw-Hill Publishing Company, Chemical Week, various issues.
Renner, Goo rge T. , et. al. , World Economic Geography. New York: Thomas Y. Crq~ell Company, 1953.
Shreve, R.N., The Chemical Process Industries. New York: McGraw-Hill Book Company, 1945.
U. S. Bureau of Mines, Bulletin 585, Mineral Facts and Problems, 1960 edition, Washington, 1960.
U. S. Bureau of Mines, Minerals Yearbook, various years.
U. S. Bureau of Mines, Mineral Resources of the United States, various years.
Whitlach, George I., Georgia's Mineral Resources, Georgia Institute of Technology, Atlanta, 1962.

Figure 1

BELL MOUNTAIN
TOWNS COUNTY, GEORGIA

0

100

200

300 Feet

Jan. 1964

quartzite .1n place

horizontal joint

quartzite float
biotite gne 1ss ..___ joint
34
vertical joint

transit station

0 shed

I I

lithologic contact,

;./ dashed where

approximate.

Diamond drill hole. Dot is location of the dr iII collar. Arrow gives direction of the hole and its projection onto a horizontal plane.

Contour elevations relative to starting plane

t.able station.
IS 3360 feet

Actual above

height of sea leveL

Bell

Mountain

60 40 20 300
E
400
eo
60 40 20 3 00
G
60 40 20 4 00
eo
60 40 20 300
I
eo
60 40 20 4 00
eo
60 40 20 300
K

Figure 2
A

--''"""'

300
eo
60 40 20
200 8
80 60 40
300
eo
60 40 20 D 200 80 60 40 20

300
eo
60
40
20
2 00
eo
60
40 20
100
eo

300
eo
60 40 20 20 0
eo
60 40 20 100
eo
60
J
300
eo
60 40 20 200
eo
60 40 20 100 80 60 40
L
300
eo
60 40
40 20 101)
eo

1----------~~~~~~~~~~~~+++~------------~---, 3 00

80 60 40

20
----------~~~~~~~--~--~ 2 0 0
eo

60

e o~-------------.------~~~~

40

6 o l---------------t---~~~~~~-

20

4 ol---------------.-~~~~~~~--

10 0

201-----------~~~~7+~~~~~~--

80

4 00 1-------~~~~~~~~~~~~~~~-

e o l-----,~~~~~~--~~~~~~~~-----

60 ~~~~~~~~~--~~~~~~~----

4 0 ~------------+--+----~~~~~~~---2 0~-------------.--------~~~~~~~------

p

3o o L-------------~~----------~~~~~~~--------------------, 3 00

0

80

60

40

20 20 0
80

4 0 r---------~~=-----~~~~----

60

2 0 ~--------~~~~~~~~~~---

40

20

10 0 80

R

300, L-------~~~~~~~~~~~~~~~~~~--------~------ 300

Q

eo

60

40

20

200
eo

60

_.,\.,.,.

I

80

~ ...,., ,-,); } ~

60

..... ~.,_, ,::;:-,,.~,; ,-::~~,-~ 1\.-\ :::::::)})~

4 0 ''... .:.--\/)',. ,;-:;,_..._,.,,/'/-.
20 300
s

I
I I

~'' :::::;~ :;:;; )-,., .:::::::>:::::<::::" '

\

~'7 "::>-.

\

.;. ::: ::.:>-., :: "<N

I
I
I

\

401

_.,.-.; , - , .. ~

. ,:..:){ \.
t -~
:- .; -.... ..

302~0 [..,-,,~..1

,,;,,

...'...\.~......I.... \1~\1~1"\."r-/

1
-

' ... ~ .,..,,-. - :-:.;- .-.

I

u _, - - ,_,. . . . ~ ' '-.... ''t' '''.... ~'---1' .. .~ ::>:<}:(?~

!.,./ .... '... ,.:. ~~, ..., I

::::;;:::;:: : :: ::::::~

I

,.,...,. >":~I

:::: : ::::::<< "-

1

:::: ~:::)-., I

::::.:;:: :.::: :>. :;:;:::"

40 20 10 0
T
300
eo
60 40 20 2 00
eo
60 40

~ :::;:::::::::":: ::}: ::: ~

:.::>::;:::: :.;:::;:.:.:,
I

..........
"_",y'-;N, n ?

:fi-

,V:J'-X''

,:/-

-

,'
/

, ,)(3'

' ' '

:'-'
~~: ~I

0

10 0

20 0

300 Feet

Jon . 1964

v

300

80

60

40

20

200
eo

60

40

20

100
eo

60

'

',
' '.;.;,No.I
.;/,;-

40 20
0
-eo

:z..-

- 60

vr:,

- 40

v; ,

- 20

- 100