corundumn.
/kɒˈrʌndəm/ 1. A crystallized mineral belonging to the same species as the sapphire and ruby, but opaque or merely translucent, and varying in colour from light blue to smoky grey, brown, and black; called also adamantine spar.
ΘΚΠ
the world > the earth > minerals > types of mineral > oxides and hydroxides > [noun] > corundum group A2 03 > corundum
corundum1728
adamantine spar1786
corindon1802
corundite1861
1728 J. Woodward Catal. Foreign Fossils i. 6 in Catal. Addit. Eng. Native Fossils Nella Corivindum is found in fields where the rice grows.
1794 R. Kirwan Elements Mineral. (ed. 2) I. 335 The second, in India, near Bombay and there called corundum.
1798 C. Greville in Philos. Trans. (Royal Soc.) 88 403 My friend Colonel Cathcart sent me its native name, Corundum, from India, with some specimens..in 1784.
1868 J. D. Dana Syst. Mineral. (ed. 5) 138 Corundum..is ground and used as a polishing material, which, being purer, is superior in this respect to emery. It was thus employed in ancient times.
1886 Pall Mall Gaz. 9 Mar. 11/2 A new process for obtaining pure aluminium from aluminium oxide or broken corundum.
2. Mineralogy. Used as the name of a mineral species, under which Dana includes the transparent sapphire (including the ruby, and the (so-called) oriental amethyst, emerald, and topaz), the opaque or translucent adamantine spar (= sense 1), and the granular emery. It consists of crystallized alumina (Al2O3) variously coloured.
ΚΠ
1804 Philos. Trans. (Royal Soc.) 94 44 Those stones which offer the greatest resistance to a mechanical division, such as quartz, blue corundum or sapphire.
1868 J. D. Dana Syst. Mineral. (ed. 5) 139 Emery..in which the corundum is in distinct crystals.
1870 H. Macmillan Bible Teachings xiv. 273 The sapphire..the ruby and the Oriental topaz..are all mere coloured varieties of the mineral substance known as corundum.
3. attributive, as in corundum point, corundum stick, corundum tool, corundum wheel, used in polishing, dressing millstones, etc.
ΚΠ
1792 Oakley in Philos. Trans. (Royal Soc.) 88 407 Among these broken lumps, the Corundum stone is found.
1873 J. Richards On Arrangem. Wood-working Factories 106 Corundum or emery wheels are now generally used for dressing both saws and cutters.
1884 F. J. Britten Watch & Clockmakers' Handbk. (new ed.) 86 The edges of holes in dials may be trimmed with corundum sticks.
This entry has not yet been fully updated (first published 1893; most recently modified version published online March 2022).
<
n.1728