RUBY.
NORTH CAROLINA.
Prospecting
at the ruby deposits on Caler Fork of Cowee Creek, in Macon County, N.
C, during part of 1914 did not result in a definite determination as to
whether or not the property can be profitably worked. Earlier work for
rubies a number of years ago in the gravel beds in the bottom land
along the creek resulted in the discovery of much red and pink
translucent corundum and of some clear stones of value as gems. The
best stones had a fine ruby color with silki-ness and slight cloudiness
in some specimens. Prospecting of the gravel beds carried the work back
to a point where the valley narrows below a flat. Here ruby corundum
was found in matrix and the hillside was called In Situ Hill. At
several different times prospecting has been carried on in this
hillside in search of the remaining part of the deposit from which the
best rubies of the placer ground have been obtained.
Prospecting
work at the In Situ Hill locality was begun in 1913 by the Consolidated
Ruby Co., of New York, and was continued in 1914. The new work
consisted of a shaft 38 feet deep from the bottom of the open cut at
the foot of the hill. From this shaft drifts were run 58 feet west and
80 feet south of east. Several holes were sunk by a churn drill, using
chilled-steel shot for cutting edges. One of these holes was 103 feet
deep, cutting through all the saprolite or decomposed rock into fresh,
unaltered gneiss. The fresh rock from the drill core consists both of
garnetiferous diorite and garnetiferous biotite gneiss. The
garnetiferous diorite would probably yield yellowish-brown saprolite
just like that found in the upper workings of In Situ Hill. No pockets
containing ruby corundum were found in the drill holes; In the shaft
and the underground workings a vein or seam was followed, in which
several small and one large pocket or deposit carrying ruby corundum
were found. The largest deposit was a shoot or chimney measuring 6-1/2
feet high by 3-1/2 feet wide, and was nearly 4 feet thick. The material
taken from this deposit, when washed, yielded about 20 pounds of
translucent pink corundum. These crystals range from small size up to a
centimeter in diameter and thickness. None of them has fine red color,
and most of them are pink to purplish red. Nearly all of the crvstals
contained small rust cavities up to 2 millimeters in diameter, formed
by the decomposition of minute rhodolite garnets similar to those
described by Pratt and Lewis.1 The corundum crystals are
inclosed in whitish kaolin-like deposits, apparently resulting from the
decomposition of feldspar or pegmatitic material which originally
inclosed the corundum. None of these rubies is of as deep a color or
is as clear as those found in the stream gravels below In Situ Hill,
but the richness of the pockets adds to the interest of prospecting for
stones of better quality.
'
Pratt. J. 11., and Lewis, J. V., Corundum and the pcridotites of
western North Carolina: North Carolina Geol. Survey, vol. 1, p.
183,1905.
