296 DESCRIPTIONS OF MINERALS. 
phiny, and the Salisbury Crag, near Edinburgh, are some 
vf the foreign localities. | 
Prehnite receives a handsome polish and is sometimes 
used for inlaid work. In China it is polished for orna- 
ments, and large slabs have been cut from masses brought 
from there. 
Chlorastrolite and Zonochlorite, from the Lake Superior region, are 
impure prehnite. 
Chaleomorphite. A hydrous calcium silicate, from calcite in cavities 
of lava, containing but 25°4 per cent. of silica. 
Gismondite (Zeagentte). A hydrous lime-aluminum silicate, occur- 
ring in trimetric crystals resembling square cctahedrons ; found in 
lava at Capo di Bove, near Rome. 
Hdingtonite. A hydrous barium-aluminum silicate. Occurring in 
crystals and massive. From the Kilpatrick Hills, with harmotome. 
Carpholite. A manganese-aluminum silicate, occurring in silky, 
yellow, radiated tufts. From the tin mines of Schlackenwald.. ’ 
Pyrosmalite. A manganese-iron silicate and chloride, from Sweden. 
Calamine. A hydrous zine unisilicate. See p. 157. 
Villarsite. Probably altered chrysolite. 
Cerite, Tritomite, Erdmaninite, are cerium and lanthanum silicates. 
Thorite (Orangite) and Hucrasite, are thorium silicates; the latter 
hydrous. 
Allophane. 
In amorphous incrustations, with a smooth small-mam- 
millary surface, and often hyalite-lhke, and sometimes pul- 
verulent. Color pale bluish-white to greenish-white, and 
deep green 5 also brown, yellow, colorless. ‘Translucent. 
== Gr==1-8d=1°39: 
Composition. Mostly Al1O;S8i+6 (or 5) aq. Silica 23°75, 
alumina 40°62, water 35°63=100. In the Breen tube yields 
much water. B.B. infusible, but crumbles. .A blue color 
with cobalt solution, and a jelly with hydrochlorie acid. 
Occurs in Saxony; at the Chessy Copper Mine near 
Lyons ; at a copper mine in Bohemia; with limonite in 
Moravia ; in Old Chalk Pits near Woolw ich, England ; with 
gibbsite in limonite beds in Richmond, Mass. : ore the cop- 
per mine of Bristol, Conn.; at Morgantown, Pa. ; copper 
mines of Polk County, ‘Tenn. 



Collyrite. A hydrous aluminum silicate containing only 14 to 15 per 
cent. of silica, and 35 to 40 of water; and Schrétterite is another with 
11 to 12 per cent. of silica. The latter has been reported as occurring, 
as a gum-like incrustation, at the falls of Little River, on Sand Moun- 
tain, Cherokee County, Alabama. Scarbroite is a related mineral 
of doubtful nature. 

