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

KYANITE DEPOSITS 103
FIGURE 57. Photomicrograph of massive kyanite from about 1 mile west of
Long Swamp, Pickens County, Ga. Shows interlocking texture of kyanite
crystals (k), with interstitial areas of fine-grained micaceous mineral, probably
muscovite (m). Compare with massive kyanite from India (fig. 58).
Plane-polarized light.
panded more than Indian kyanite when calcined,
it produced a coarse grog, nearly 60 percent of
which was coarser than 35-mesh. Standard bricks
made from the calcined material were lighter and
more porous than those made from Indian kyanite.
One undesirable feature of the Georgian kyanite,
however, is that much of it contains some fluxing
materials, iron oxide and muscovite, that cannot be
removed by hand cobbing, or even by scrubbing.
Deposits of massive kyanite of minable size have
not been found in this area.
TALBOT, UPSON, AND HARRIS COUNTIES
Kyanite occurs in the belt of Manchester schist
overlying the Hollis quartzite at several places between
Thomaston and Hamilton in west-central
Georgia; the extent of the Manchester schist and
associated Sparks schist is shown on the geologic
map of Georgia (Stose and Smith, 1939).
The occurrences of kyanite in Talbot and Upson
Counties are described by Crickmay (Prindle and
others, 1935) and Clarke (1952). Small kyanite
crystals are associated with quartz veinlets and
pegmatite stringers in a zone of graphitic garnetmuscovite
schist, about 30 feet thick and 200 feet
above the base of the Manchester schist (Prindle and
others, 1935). Crickmay reports that at places the
kyanite seems more abundant in the soil than in
the bedrock. A sample of soil from the Cherry property
(31/2 miles southwest of Thomaston), weighing
82 pounds, yielded 12 ounces of kyanite by
washing, equivalent to a little less than 1 percent
kyanite by weight (Prindle and others, 1935). Kyanite,
staurolite, and garnet are found in the soil
here over an area about 1,400 feet long and 50 to
200 feet wide (Ingram, 1950). A sample of kyanite
schist taken from the west bank of the Flint River,
l*/2 miles below Pasley Shoals, was found by
Clarke (1952) to contain about 8 percent kyanite.
He also found that feldspathic gneisses surrounding
a large granite body near Thomaston commonly contains
1 to 3 percent kyanite; 1 specimen contained
1 percent kyanite and 2 percent sillimanite.
In Harris County near the western end of the
belt of Manchester schist, kyanite was found in the
alluvium of Mountain Creek by D. W. Caldwell
(written communication, 1952) during the Geological
Survey's study of the distribution of monazite
in Southeastern placer deposits. Samples of alluvium
from several localities contained about 1/2 to
1 percent kyanite in particles less than one-quarter
of an inch long. Mountain Creek drains an area of
Manchester schist here, which is presumed to be
the source of the kyanite. The Hollis quartzite extends
westward from here into Alabama (Hewett
and Crickmay, 1937), and perhaps the overlying
Manchester schist does also; there seems to be
no published record on the occurrence of kyanite
schist along the extension of this belt in Alabama.
OTHER LOCALITIES
On the T. F. Carter property, Fulton County,
about 11/2 miles southwest of Dunwoody, kyanite
occurs in kyanite-garnet-mica schist, and is found
in the soil in a belt 320 feet wide and at least 600
feet long (Crickmay, in Prindle and others, 1935).
The locality had not been thoroughly prospected
,,%1
FIGURE 58. Photomicrograph of massive kyanite from India. Shows interlocking
texture of kyanite crystals (k), with abundant inclusions of tiny
rutile grains (r). Plane-polarized light.