1. Any of several common, widespread aluminum or calcium silicate minerals occurring in two internally isomorphic series, (Mg, Mn, Fe)3Al2Si3O12 and Ca3(Cr, Al, Fe)2Si3O12, generally crystallized, often embedded in igneous and metamorphic rocks, and colored red, brown, black, green, yellow, or white and used both as gemstones and as abrasives.
2. A dark to very dark red.
[Middle English, from Old French grenate, from grenat, pomegranate-red, probably from Latin grānātum, pomegranate, from neuter of grānātus, seedy; see POMEGRANATE.]
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