GARNET, a precious stone, some of the varieties of which are of great beauty; while some are less highly prized than other not more beautiful minerals, because much more common. Garnets are found most generally in mica-slate, hornblende slate, and gneiss; less frequently in granite and granular limestone; sometimes in serpentine and lava. There are numerous varieties, differing considerably in chemical composition ; anhydrous silicates of alumina and lime or magnesia, colored with oxide of iron, of manganese, or of chrome. The color is various, generally some shade of red, brown, black, green, or yellow. Colorless and white specimens also occur. Red garnets sometimes contain so much iron•as to be attracted by the magnet. The coarser variety of G., known as COMMON G., is generally found massive, often forming a very considerable part of tho rock in which it occurs, so as even to be used as a flux iu.the smelting of iron. Crystal lized garnets are also often very numerous in the rock which contains them; the crys tals are sometimes very small, almost imperceptible grains; sometimes they are as large as a man's fist. The-primary form of the crystal is a cube, but the common secondary forms are a rhombic dodecahedron, and an acute double eight-sided pyramid. the
!nits of which are abruptly acuminated by four planes.=Nonns: G., or PnEcrous G., also called almandine, is generally of a crimson-red color, sometimes of so deep a tint, that jewelers it out beneath, or place at the back of it a plate of silver. It Li sometimes transparent, sometimes only translucent. It is found In softie of the mountain, ous parts both of England and Scotland, but the finest garnets are imported from Syrian], in Pegu. A Syrian] G., of a velvety black color, without defect, is valued at about half the price of a blue sapphire of the same weight. The large specimens of the precious G., are generally engraved with figures, and thus acquire a very high value.— A varietrof G., known as grossularia, from its resemblance, in form, size, and color, to .a green gooseberry, is tirought from Siberia.—Cinnamon stone (q.v.) is a variety of ga• net.—Pyrope, Vesuvian, and epidote are nearly allied to it.—Powdered garnets are often used for polishing and cutting other stones; this powder is known to lapidaries as red emery.