66 CORUNDUM IN THE UNITED STATES. [bull. 180. 
SOUTH CAROLINA. 
In the northeastern part of York Comity, from 3 to 4 miles west of 
the Catawba River, on the land between Allison and Crowder creeks, 
corundum has been found in a belt about 200 to 300 j^ards wide which 
skirts along the western slopes of Nannies Mountain. ' This locality 
is about 12 miles northeast of Yorkville, S. C, and 25 miles southwest 
of Charlotte, N. C. 
Mining operations have been carried on at two distinct port ions of 
this belt, one a mile north of the summit of Nannies Mountain, on 
the property of Alexander Rickard. The work done here consists of 
a shaft about 35 feet deep, from which several drifts have been run, 
which penetrate what is probably a light-gray granite, but it is much 
decomposed and of a sandy constituency. The only solid material 
encountered were irregular masses of black cleavable corundum asso- 
ciated with muscovite mica. In the surrounding fields float corundum 
ranging in size from small particles to masses of several pounds in 
weight are abundant, and many tons of this have been picked up and 
shipped. 
A little to the west of the south end of Nannies Mountain, about 
H miles from the Rickard mine, there is a similar occurrence of 
corundum. There have been a number of shallow cuts, ditches, and 
pits made in prospecting for corundum, but apparently none was 
found in place. The corundum that was found is often wrapped in 
mica. 
The mode of origin of this corundum has not been determined, for 
up to the present time the exact nature of its occurrence is not defi- 
nitely understood, as no exposure of the corundum can be seen which 
shows its relation to the rock in which it occurs. Neither can it be 
stated whether it is to be found in quantity. 
PENNSYLVANIA. 
The corundum in this State, so far as can be learned, is all associated 
with the serpentine rocks in Chester and Delaware counties and occurs 
near the contact of this rock with the gneiss. Considerable feldspar 
(plagioclase) similar to that described from the Big vein at Buck 
Creek, N. C, is usually crystallized out with the corundum. 
Corundum has been found more abundantly near tlnionville, in 
Newlin Township, Chester County. It is found here in a mass of ser- 
pentine rock, with an average width of about 800 feet and a length of 
1 mile. A number of tons of corundum have been obtained from this 
mine, but during the last ten years little or no work has been carried 
on here. Associated with the corundum are tourmaline and spinel. 
MONTANA. 
Most of the corundum that has been found in Montana has been of 
the sapphire variety, but at one locality near Bozeman, Gallatir 
