J. L. Smith—Corundum of North Carolina, ete. 183 
matic, affording the finest perfect crystals yet seen, from which 
M. Dufrenoy made his last study of the crystallography of this 
mineral; and the emery is associated with calcareous rock over- 
lying gneiss.) The Kulah emery from the same part of the 
world is equally in calcareous rock, and has very little chlori- 
ee is 
oritoid 
is caleareous, that in Chester, Mass., has hornblendic gneiss im- 
mediately on one side of the vein, and is accompanied with a 
large amount of magnetic oxide of iron. Tourmaline also 
abounds in this corundum, and like the Asiatic variety 1t con- 
a single six-sided pyramid, whose summit is terminated by 
rather an uneven and somewhat undefined hexagonal plane. 
The smaller crystal is a regular hexagonal prism, well terminated 
at one of its extremities, the other being drusy and incomplete. 
The general color of this crystal is a grayish-blue, though there 
are spots, particularly near the an les, where it 1s of a pale 
sapphire tint. Its greatest breadth is six inches, and its length 
over five. Some of the lateral planes are coated in patches with 
a white pearly margarite. ‘ 
: The smaller crystals are often transparent at their extrem- 
ities. It is, however, in color that the corundum of this ocal- 
ity excels. It is gray, green, rose, rub 
sapphire-blue, and all intermediate shades to colorless. Many 
pieces of the blue and red have been cut and polished, present: 
ing very good characters as gems, without being of the finest 
quality, ; 
ace, This Journal, TH, iv, 109, 175, (1872), in an elaborate memoir “on the Corun- 
um region of North Carolina and Georgia.” 
