“ ae Gibbs on Tourmalines, &-c. 
“the exterior raeytal Sometimes a thin layer of talc intervenes 
between the outer and .inner crystal. In one specimen I 
found three crystals of the red aggregated together, and en- 
closed in one of the green. In another crystal I found pyrites 
in the place of the red tourmaline. The largest crystal of 
the red was one quarter of an inch in diameter, and four 
inches long. The red tourmalines vary in intensity of color, 
and frequently (particularly in the interior) pass into violet. 
They pass from translucid to semi-transparent. I have found 
some that were terminated by triedral pyramids. The crystals 
are generally perpendicular to the sides of the vein. Small 
crystals of the red often run from the vein of quartz into the 
adjoining feldspar. The granite also contains minute crys- 
tals of dark and light blue tourmaline, and pale green eme- 
rald, with a very few garnets and pyrites. In the lower part 
of the vein, five or six feet from its interruption by the mica 
- slate, the red tourmaline scarcely appears, and the vein con- 
tains chiefly bluish amorphous quartz and green tourmaline. 
It is therefore probable that this vein will not afford hence- 
forward a great supply of this beautiful mineral. 
About six miles from Chesterfield, in Goshen, is found the 
rose mica with tourmalines and emeralds interspersed in the 
granite. Unfortunately the bed of granite has not been dis- 
covered, and the specimens we possess are taken from loose 
_- rocks, scattered over a small extent of ground in a valley, in 
-the neighborhood of mica slate. The rose mica is found in 
a large grained granite with amorphous quartz and siliceous 
feldspar, crystallized and amorphous. The mica is generally 
of a rose red, sometimes yellowish green. It crystallizes in 
rhomboidal tables, rarely truncated on the acute angles, 
passing into the hexaedral table. The tourmalines are light 
and dark green and blue, of various shades of intensity, fre- 
quently acicular and stellated. The black, the red, and the 
' violet tourmalines also occur, but more farkly’ Sometimes 
the green prisms enclose others of blue and black. Specific 
gravity of these varieties from 3 to 3.1. The green and blue 
crystals in this locality are translucid or semi-transparent. 
The feldspar is generally white, rarely light blue. There are 
