Serpentine

Collier's New Encyclopedia (1921)

an abundant mineral occurring in one or other of its numerous varieties in all parts of the world. Crystallization, probably orthorhombic, but when found in distinct crystals always pseudo-morphous. Occurs usually massive, but sometimes fibrous, foliated, fine granular to cryptocrystalline. Color shows many shades of green, yellow; streak, white, shining ; translucent to opaque; fe feel, greasy; fracture, either conchoidal or splintery. Composition: Silica, 44.14; magnesia, 42.97; water, 12.89= 100, corresponding with the usually-accepted formula, 2MgOSiO2+MgO, In petrology, a rock, consisting essentially of a hydrated silicate of magnesia, resulting from the alteration of magnesian rocks, of all geological ages, especially those of olivine . It contains also some protoxide of iron, and other impuricolor, which is often of a dull green, but ties which cause a great variation in is also marbled and mottled with red and purple. It takes a high polish, and is turned into ornamental articles . The accessory minerals are numerous, the most frequent being pyrope, bronzite, magnetite, and chromite. In geology, serpenrock, originally a trap or dolerite with tine is considered an altered intrusive olivine. town, 57 miles by rail S. of Moscow, on SERPUKOFF , an ancient Russian the Nara, 3 miles from its confluence with and was before the World War, a place the Oka. It contains a cathedral ( 1380), of considerable commercial and industrial tons, woolens, leather, paper, furniture, importance, manufacturing chiefly cotand earthenware. Pop. about 31,000. It was formerly a fortress protecting Moscow on the S. in tufts attached to the head and anterior Annelida, whose organs of respiration are