SAPPHTEE TN UNITED STATES. 101 
most part similar to those belonging to the rliododendrons and roses; 
its surprisingly small amount of coloring matter; its gem-like trans- 
parency; its freedom from internal imi)erfections, microscopic inclu- 
sions, and strite, the characteristic imperfections of common garnets; 
also its remarkable brilliancy when cut as a gem. There is but one 
variety of garnet noAv known which approaches it, when in gem form, 
in this last respect, and that is the green demantoid of Siberia, which 
often vies with the diamond in its luster and dispersive effect upon 
light. Most garnets are beautiful only by transmitted light, and then 
exhibit only dark shades of color, but these new^ garnets give most 
beautiful effects of brilliant and varied coloring by reflected light 
alone, thus proving the uncommon purity and great clearness of this 
new material. 
As has been said, there is no limestone in this immediate vicinity, 
and these rubies Avere probably derived from an amphibolite or eclo- 
gite. The usual tabular form of the crystals is one that seems to be 
characteristic of the gem corundum Avhen found in igneous rocks. 
The CoAA^ee Creek rubies frequently contain inclusions, some of 
which are very minute, knoAvn to jeAvelers as " silk," and these give 
rise to a cloudiness or sheen in the polished gem. Some gems from 
this mine liaA^e been cut that Avere 3 or 4 carats in weight, free 
from inclusions, of fine color, and transparent. A great many 
smaller ones have been cut that are perfect gems. In color and bril- 
liancy these gems are equal to the Burma ruby, and if the percentage 
of the unflawed, transparent material increases but little, this ncAV 
field wall be a worthy rival to the Burma field. A considerable per- 
centage of the transparent material is often very badly flaAA^ed by 
cracks due to parting and injured by the inclusions of rutile or 
menaccanite, so that the percentage of perfect stone from this mine is 
small. This, hoAA^CA^er, is true of the rubies from the Burma field also, 
for a large proportion of the rubies on the m.arket to-day are usually 
more or less flaAved Avith the parting cracks. 
The pleochroism exhibited by the Cowee rubies is very marked, 
some of them being a very rich pigeon-blood red in the direction of 
the A^ertical axis — that is, looking doAvn upon the basal plane — and 
changing to an almost pinkish-Avhite color AAdien A^iewed at right 
{ingles to this or looking through the prism. The pleochroism which 
nearly all the deep-colored A^arieties of corundum gems exhibit is one 
of the means of identifying a corundum gem. This often interferes 
Avith the cutting. 
The ruby crystals * from the CoAvee Valley show a very Avide varia- 
tion in their development. Although many of the crystals are so 
striated that no crystallographic measurements were possible on the 
" Am. Jour. Sci., 4th ser., vol. 8, 1899, p. 379. 
