The chrysolite, peridot, and olivine differ in color, but are practically of the same composition. The chrysolite proper is of a pale greenish-yellow color, the peridot a deep olive-green, and the olivine of a yellowish or light olive-green color; these stones also shade into brown. They crystallize on the rhombic system, are transparent to translucent, 6.5 to 7. in the scale of hardness, and 3.3 to 3.5 in specific gravity. The cleavage is distinct, fracture conchoidal, refraction double, and lustre vitreous, and in the olivines somewhat greasy. These stones are easily affected by sulphuric acid, but are infusible With borax, they melt to a pale-green transparent glass. Chrysolites are composed of silica, magnesia, and oxide of iron. Perfectly crystallized chrysolites are brought from Constantinople, but the exact locality where they are found is unknown. Less distinct specimens occur at Vesuvius, Mexico, the isle of Bourbon, Auvergne, Egypt, Natolia, Brazil, Germany, Pegu, Ceylon, Switzerland, and North America. Peridots are distinguished by being the only precious stones that have literally dropped from heaven, as they have been found in meteorites. The Oriental chrysolite of commerce is true chrysoberyl, and is harder and heavier than chrysolite, and the stone called Ceylon chrysolite is The green garnet is of a pronounced green color, and is harder and heavier than the olivine or chrysolite. Although suitable for mounting in brooches and other ornaments, these stones are not sufficiently hard for the rough usage as ring-stones. |