garnet1 (garnet)

[ from its resemblance in color and shape to the grains or seeds of the pomegranate [L. grana tum: see pomegranate ]" (Webster); cf. garnet apple. The ult. source is the same; gran at and grenade are doublets.] A common mineral species embracing many varieties, which, while conforming to the same general formula, differ in composition and hence also in color, specific gravity, and fusibility. It generally occurs in dis. tinct embedded crystals belonging to the isometric system, the rhombic dodecahedron and trapezohedron being the commonest forms. There are also ma ive granular varieties. It is hard, brittle, and more or le transparent. The red varieties are most common, but white, yellow, green, brown, and black also occur. The prominent varieties are: (1) the lime-alumina garnet, including the gro ular garnet, succinite, and cinnamon-stone or he onite; (2) the magnesia-alumina garnet, including pyrope; (3) the iron-alumina garnet, including the almandin or the precious garnet and much common garnet; (4) the manganese-alumina garnet or spe artite; (5) the lime-iron garnet, sometimes called in general andradite, including haplome, colophonite, topazolite, demantoid, and melanite; (6) the lime-chrome garnet or ouvarovite. Garnets are commonly found in gnei , mica schist, granite, and hornblende rocks. Eclogite is a rock consisting largely of garnet. The precious garnet is transparent and deepred, includes some pyrope, and is prized as a gem, as is also the brilliant bright-green demantoid from Siberia. White garnet, a name given (in 1776) to leucite, because of the similarity of its crystals to a common form of garnet.