It occurs in Norway, Switzerland, and in the Tyrol; in Virginia, Massachusetts, North Carolina, and Arkansas.
Cobalt Diarsenide. Essentially like Smalite, occurring in crystals,
also massive and with fibrous radiated structure. Color tin-white soon
tarnishing to dark gray.
It occurs with Smalite, and implanted upon it, at Schneeberg, Saxony.
variety of transparent quartz with inclusions of Rutile, Asbestos,
Hornblende or Chlorite. It is used as an ornamental stone, and its
value as a gem stone depends
for its beauty on the slender crystals or fiber of some other mineral.
It is sometimes called "Fleche d'Amour" and is cut into heart shaped
lockets and other pendant jewelry.
Salt: (See Halite.)
Niobate of Uranium, Iron and Manganese. The exact composition has not
been wholly determined. It occurs crystallized in the orthorhombic
is usually massive, color varying from velvet-black to brownish-black.
as large as 200 pounds, containing 12 to 20% Uranium Oxide, have been
obtained at Madras, India, where it is mined and sold as a radioactive
mineral. (See Radium.)
deep cornflower-blue, transparent variety of Corundum. A very hard
precious stone of the same composition as the Ruby, and like the Ruby,
next in hardness and value to the Diamond.
finest Sapphires are usually obtained from the beds of rivers, the best
specimens being brought from Ceylon, often as rolled pebbles as well as
in crystals. Gem Sapphires are also found near Helena, Montana in gold
washings; in California and in Ontario.
The Star Sapphire is the result of inclusions reflecting back the light in the form of a six-pointed star.
Sapphires are very attractive and popular as gem stones and are used also as meter bearings, watch jewels, etc.
"Brazilian Sapphire" is a variety of blue, transparent Tourmaline.
Sardonyx: An Onyx in which some of the bands consist of Car-nelian. It is usually red and white and is used as an ornamental stone.