phides of silver and copper in Silesia; in Chile; and also in California, Arizona and Colorado.
Strontianite: Strontian
Carbonate. Carbon Dioxide 30%, Stron-tia 70%. A little calcium is
sometimes present. This comparatively rare mineral, originally found at
Strontian, England, occurs in acicular and twinned crystals, in
globular forms, fibrous and granular. The color is pale
asparagus-green, apple-green, and also white, gray, yellow and
yellowish-brown.
The
nitrate of Strontia is used in making fireworks, as it communicates a
magnificent red color to flame. The hydroxide of Strontia is employed
in the separation of sugar from molasses.
Sulphur: A
non-metallic element existing in many forms, found in great abundance
in the Mineral Kingdom, sparingly in the Vegetable Kingdom, and still
more so in the Animal Kingdom. It occurs in nature as a lemon-colored
powder, as spherical or globular masses, as stalactites, and in
crystals, which are yellow with a lemon-yellow streak. Massive forms
are yellow to brown. It occurs most abundantly in regions of active or
extinct volcanoes especially in Italy and Sicily, Hawaii and Japan. In
the United States, in Texas, Louisiana, Wyoming and Nevada.
Sulphur
is used in the manufacture of matches, gun-powder, and in vulcanizing
rubber to increase its strength and elasticity. Also in the preparation
of certain compounds.
Sunstone: A
translucent variety of feldspar exhibiting reddish flashes from
inclusions of mica, or other platy materials. It is used as a gem, the
stones being polished in such a
way as to bring out these reflections to the best advantage.
Sylvanite:
Gold and Silver Telluride. Tellurium 62%, Gold 24.5%, Silver 13.4%.
Occurs in crystals, (twins and skeleton forms common), also bladed and
imperfectly
columnar to granular. Color silver-white to yellowish-gray. It is
mined as a Gold and Silver ore chiefly in the Cripple Creek District,
Colorado.
Sylvite: Potassium
Chloride. Chlorine 47 6%, Potassium 52.4% Occurs in isometric crystals,
cubic in habit, with physical properties like Halite except in
hardness. It is colorless, white, bluish, or yellowish-red from
inclusions and occurs with Halite at Stassfurt Germany, and in Galicia.
It is an important source of potassium salts, large quantities of which
are used in the manufacture of fertilizers.
