WordWeight : Weighing the Words

Pronunciation : Co*run"dum (k-rn"dm)
Part of Speech : n.;
Etymology : [From Hind. kurand corundum stone.] (Min.)
Definition : Defn: The earth alumina, as found native in a crystalline state, including sapphire, which is the fine blue variety; the oriental ruby, or red sapphire; the oriental amethyst, or purple sapphire; and adamantine spar, the hair-brown variety. It is the hardest substance found native, next to the diamond.

Note: The name corundum is sometimes restricted to the non- transparent or coarser kinds. Emery is a dark-colored granular variety, usually admixed with magnetic iron ore.

pl. Corundums (-d. [Also corindon.]
Source : Webster's Unabridged Dictionary, 1913