952 DESCRIPTIONS OF MINERALS. 
cirty, need only be thrown into the fire for a few minutes 
to be white again. ‘The ancients, who were acquainted with 
its properties, are said to have used it for napkins, on ac- 
count ‘of the ease with which it was cleaned. It was also 
the wick of the lamps in the ancient temples; and because 
15 maintained a perpetual flame without being consumed, 
they named it asbestos, unconsumed. It is now used for 
the same purpose by the natives of Greenland. The name 
amianthus alludes to the ease of cleaning it, and it is de- 
rived from amitantos, undefiled. Asbestus is extensively 
used for lining iron safes, and for protecting steam pipes 
and boilers. ‘Lhe best locality for collecting asbestus in the 
United States is that near the Quarantine, in Richmond 
County, N. w: 
Anthophyllite is related in the angle of its prism to hornblende, but 
is trimetric. In composition and its infusibility before the blowpipe, 
it is near bronzite. B.B. it becomes magnetic. From Kongsberg in 
Norway, and near Modum. Kupjferite has the hornblende angle, but 
in composition it is like enstatite, being a magnesium silicate. 
Arfvedsonite. Near hornblende; but contains over 10 per cent. 
of soda, like acmite. 
Crocidolite. Near arfvedsonite in composition. A lavender-blue or 
leek-green fibrous mineral from Orange River, South Africa, and from 
the Vosges ; also from Rhode Island (A. H. Chester). 
Gastadite. A dark blue to azure-blue mineral related to amphibole, 
from the valleys of Aosta and Locano. 
Gliucophane. A bluish mineral with the amphibcle angle, from the 
Island of Syra. Wichtisite may be the same mineral. 
Milarite. 'Trimetric, of the composition (KH)Ca, AlO,,Si,,; the 
quantivalent ratio for bases and silica 1:4; being theretore a quater- 
silicate instead of a bisilicate. 
Beryl.—Emerald. 
Hexagonal. In hexagonal prisms, usually without regular 
terminations. Cleavage basal, not very distinct. 
Rarely massive. 
Color green, passing into blue and yellow ; 
color rather pale, excepting the deep and rich 
green of the emerald. Streak uncolored. Lus- 
tre vitreous ; sometimes resinous. ‘Transparent 
to subtransiucent. Brittle. H.= 75-8. G.= 
2°65—2°75. 
VARIETIES. The emerald is the rich green variety ; it owes 
its color to the presence of chromium, Beryl includes the 
paler varieties, which are colored by oxide of iron. <Agua- 

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