Serpentine
an abundant mineral occurring in one or other of its numerous varieties in all parts of the world. Crysorthorhombic, but when found in distinct crystals always usually massive, but sometimes fibrous, foliated, fine granular to cryptocrystalline. Color shows many shades of green, yellow; streak, white, shining; translucent to opaque; feel, greasy; fracture, either con- 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 sian rocks, of all geological ages, espe- . It contains also some protoxide of iron, and other impuri- SERRANUS color, 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 acnumerous, the most frequent being pyrope, bronzite, magnegeology, serpenrock, originally a trap or dolerite with tine is considered an altered intrusive olivine. town, 57 miles by rail S. of Moscow, on