Corundum
[kә'rʌndәm]
Definition
(n.) 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.
Edited by Carlos
Definition
n. a mineral consisting of mere alumina yet of great specific gravity—about four times that of water—and second in hardness only to the diamond.
Typist: Pansy
Examples
- The Eastern nations have used corundum for this purpose for ages. William Henry Doolittle. Inventions in the Century.
- Knight says: The corundum stone used by the Hindoos and Chinese is composed of corundum powdered, two parts; lac resin, one part. William Henry Doolittle. Inventions in the Century.
Typed by Bush