color,
and translucent or opaque. It occurs massive, in fibrous crystals, or
disseminated in tiny grains through certain rocks.
It is found in France, Saxony, in Ontario, and in Colorado and Nevada.
Anorthite: Soda
Feldspar. Color white, grayish, reddish, with uncolored streak. It is
found in vein masses, in the more basic rocks, occasionally in
meteorites, and also
in lava fields in well-defined separate crystals evidently ejected by
the volcano. It occurs in Silesia, Hungary, Tyrol, Italy, Japan, and
in Maine, Pennsylvania and Maryland.
It is used in the manufacture of pottery.
Anthophyllite: An
Orthorhombic Amphibole. A mixture of iron and magnesium silicates and
is named from antho-phyllum, meaning "clove," in allusion to its
clove-brown color, though it is sometimes green. It is found in
crystalline schist and alters to talc, occurring in Norway, Scotland,
and in Jenk's corundum mine, at Macon, Georgia.
Antimony:' A
brittle metal of a bluish-white or silver-white color, occurring in two
forms, crystalline and amorphous Sometimes found native or alloyed with
other metals. Some of the antimony used in the arts is produced from
its sulphide, Stibnite. Owing to the fact that it expands at the moment
of solidifying, it is of use in type-founding and in casts as a
constituent of an alloy. It is also used in fireworks.
Apatite: Phosphate
of Calcium. An important source of phosphoric acid. This mineral is
also called "Asparagus Stone" on account of the bluish-green color of
some varieties, though it may possess almost any color. When pure it
is used in the manufacture of phosphorus; the impure variety is used
chiefly as a fertilizer.
Apophyllite:
Hydrated Silicate. This mineral is recognized by its crystallization
and pearly luster. In color it is white, grayish, flesh-color or red.
It is transparent, brittle and strongly pyro-electric. It occurs in the
cavities of volcanic rocks, in veins in granite and limestones, in
Silesia, Tyrol, Sweden and Greenland; also in Nova Scotia, Brazil and
in Colorado and New Jersey.
Aquamarine: A
green-blue variety of Beryl that is used extensively as a
semi-precious stone. Aquamarines cover a very limited range of color,
from a light greenish-blue to a light bluish-green, slightly resembling
some of the lighter
