'Corundum' definitions:
Definition of 'corundum'
(from WordNet)
noun
Very hard mineral used as an abrasive [syn: corundom, corundum]
Definition of 'Corundum'
From: GCIDE
- Corundum \Co*run"dum\ (k[-o]*r[u^]n"d[u^]m), n.; pl. Corundums (k[-o]*r[u^]n"d[u^]mz). [Also corindon.] [From Hind. kurand corundum stone.] (Min.) The mineral alumina (Al2O3), as found native in a crystalline state. Transparent varieties are used as gemstones, 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. [1913 Webster +PJC]
- 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. [1913 Webster]