garnet

n. [ OE. gernet, grenat, OF. grenet, grenat, F. grenat, LL. granatus, fr. L. granatum pomegranate, granatus having many grains or seeds, fr. granum grain, seed. So called from its resemblance in color and shape to the grains or seeds of the pomegranate. See Grain, and cf. Grenade, Pomegranate. ] (Min.) A mineral having many varieties differing in color and in their constituents, but with the same crystallization (isometric), and conforming to the same general chemical formula. The commonest color is red, the luster is vitreous, and the hardness greater than that of quartz. The dodecahedron and trapezohedron are the common forms. [ 1913 Webster ]

☞ There are also white, green, yellow, brown, and black varieties. The garnet is a silicate, the bases being aluminia lime (grossularite, essonite, or cinnamon stone), or aluminia magnesia (pyrope), or aluminia iron (almandine), or aluminia manganese (spessartite), or iron lime (common garnet, melanite, allochroite), or chromium lime (ouvarovite, color emerald green). The transparent red varieties are used as gems. The garnet was, in part, the carbuncle of the ancients. Garnet is a very common mineral in gneiss and mica slate. [ 1913 Webster ]

Garnet berry (Bot.), the red currant; -- so called from its transparent red color. --
Garnet brown (Chem.), an artificial dyestuff, produced as an explosive brown crystalline substance with a green or golden luster. It consists of the potassium salt of a complex cyanogen derivative of picric acid. [ 1913 Webster ]