Kyanite, Sillimanite, and Andalusite Deposits of the Southeastern ...

SILLIMANITE DEPOSITS 107
tized sillimanite; when ground to minus 200-
mesh it yielded a flotation concentrate that contains
62.6 percent A12O3 and 2.0 percent Fe2O3, with
recovery of 80 percent of the sillimanite.
In Gaston and Lincoln Counties in the Kings Mountain
district, thin layers and lenses of sillimanite
quartzite and schist occur in zones adjacent to the
east and west sides of the Yorkville quartz monzonite
body; long- narrow inclusions of sillimanite
schist, sillimanite gneiss, and microcline-sillimanitecorundum
gneiss are present within the quartz
monzonite near its western contact (pi. 7). These
deposits are described in the section on the Kings
Mountain district (p. 90). Some of the sillmianitebearing
belts in the Kings Mountain quadrangle had
previously been mapped as kyanite quartzite by
Keith and Sterrett (1931).
SOUTH CAROLINA
The Piedmont sillimanite schist belt extends
northeasterly across South Carolina through Anderson,
Greenville, Spartanburg, Laurens, and
Cherokee Counties (Smith, L. L., 1945; Hudson,
1946; Teague, 1950; Overstreet and Griffitts, 1955).
Sillimanite occurs in biotite-muscovite-quartz
schists that generally contain a little graphite; garnet
and tourmaline are also present at some localities.
The sillimanite schists are generally intruded
by innumerable small lenses and thin stringers of
pegmatite and granite. Large bodies of biotite
granite are widespread, and L. L. Smith (1945)
concluded that much of the sillimanite schist occurs
as roof pendants in the granite, and that the sillimanite
schists were formed by contact metamorphism
of aluminous sedimentary rocks.
The sillimanite schist belt in South Carolina has
been investigated by the U.S. Bureau of Mines, the
South Carolina Geological Survey, and the South
Carolina Research, Planning and Development
Board in an effort to discover deposits of potential
economic importance. Overstreet and Griffitts
(1955) have outlined the area of sillimanitic rocks
in the State. One of the most promising areas is
in Pelzer and vicinity in Anderson and Greenville
Counties, where 9 bodies of schist were found,
ranging from 30 to 240 feet in surface width
(Hudson, 1946). A sample of sillimanite schist
weighing 7,500 pounds and containing 17 percent
sillimanite was taken by the Bureau of Mines from
an outcrop, 20 feet in width, on the Beam property
near Pelzer. Flotation tests of the sample yielded
satisfactory sillimanite concentrates from which
test refractory bricks of high quality were made
510Z05 O - 60 -8
(Rampacek, Clemmons, and Clemmer, 1945). Samples
from 3 diamond-drill holes drilled to maximum
vertical depths of about 100 feet by the Bureau of
Mines indicated considerable granite with thin layers
of sillimanite schist; samples from 1 drill hole
contain between 6 and 10 percent sillimanite, and
those from another hole have about 31/2 percent.
Samples from 3 holes drilled to a maximum vertical
depth of 65 feet on the Pearson and Scott
properties, three-quarters of a mile northeast of the
Beam property, also contain a lower sillimanite content
than indicated by surface exposures and float;
the highest sillimanite content of the drill samples
is about 6 percent.
The Alexander and Barber properties (Hickman,
1947) and the Gideon property (Dosh, 1950) in
southeastern Spartanburg County were also explored
by diamond drilling by the U.S. Bureau of
Mines. Two drill holes at the Alexander property
penetrated mostly granite at shallow depths; samples
from 1 hole contain no sillimanite and from
the other between 1 and IVa percent. The best
samples taken from 5 drill holes at the Barber property
contain about 5 percent sillimanite. At the
Gideon deposit, iVa miles southwest of Cross Anchor
on South Carolina Highway 92, high-grade
coarse sillimanite-biotite-quartz schist (fig. 22) is
found in roadside outcrops and as float in the
fields; 6 shallow drill holes here penetrated granite
and very little sillimanite schist.
Other areas examined by the Bureau of Mines
are in the vicinity of Greer, Taylors, and Paris
Mountain, Greenville County (Hudson, 1946). Two
samples of sillimanite schist taken near Greer contain
12 to 18 percent sillimanite. In beneficiation
tests on these samples, 65 percent of the total
sillimanite in 1 sample was recovered and 76 percent
in the other; the product was much finer
grained and had more iron than the material from
near Pelzer. Ten bodies of sillimanite schist as
much as 700 feet wide were found in the Taylors
area; 3 samples contain from 6 to 8 percent sillimanite.
The schist at Paris Mountain on the west
side of the belt is cut by many granite bodies
and has a low sillimanite content.
Additional occurrences of sillimanite schist were
found in 1949 by J. K. Yates and S. D. Heron12
at Buck and Island Creeks in northeastern Spartanburg
County, the Thicketty Mountain area in northwestern
Cherokee County, the Tyger River and
Enoree areas in southeastern Spartanburg County,
12 Investigation carried out by the South Carolina Research, Planning and
Development Board. The unpublished reports and maps of Yates and Heron
were made available to the writers by B. F. Buie of the Board.