corundum

[kuh-ruhn-duh m]

SEE MORE SYNONYMS FOR corundum ON THESAURUS.COM

noun

a common mineral, aluminum oxide, Al2O3, notable for its hardness: transparent varieties, as sapphire and ruby, are used as gems, other varieties as abrasives: often made synthetically.

Origin of corundum

1720–30; < Tamil kuruntam; akin to Sanskrit kuruvinda ruby

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for corundum

jewel, gem, rhinestone, paragon, ice, lozenge, rock, zircon, corundum, rhombus, allotrope, solitaire, brilliant, bort, jager

Examples from the Web for corundum

Historical Examples of corundum

To polish diamonds they make use of the powder of adamantine spar, or the corundum stone.
Travels in China, Containing Descriptions, Observations, and Comparisons, Made and Collected in the Course of a Short Residence at the Imperial Palace of Yuen-Min-Yuen, and on a Subsequent Journey through the Country from Pekin to Canton
John Barrow
Pliny says, corundum was used in the form of a splinter fixed in an iron style.
Scarabs
Isaac Myer
The stones have been rubbed into shape apparently by corundum.
Scarabs
Isaac Myer
The color of corundum is usually brown, but it varies greatly.
Geology
William J. Miller
There are indications of sapphires and other forms of corundum.
Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 5
Various

British Dictionary definitions for corundum

corundum

noun

a white, grey, blue, green, red, yellow, or brown mineral, found in metamorphosed shales and limestones, in veins, and in some igneous rocks. It is used as an abrasive and as gemstone; the red variety is ruby, the blue is sapphire. Composition: aluminium oxide. Formula: Al 2 O 3 . Crystal structure: hexagonal (rhombohedral)

Word Origin for corundum

C18: from Tamil kuruntam; related to Sanskrit kuruvinda ruby

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for corundum

"very hard mineral," 1728, from Anglo-Indian, from Tamil kurundam "ruby sapphire" (Sanskrit kuruvinda), of unknown origin.

corundum in Science

corundum

[kə-rŭn′dəm]

An extremely hard mineral occurring in many colors, either as shapeless grains or as rhombohedral crystals. It also occurs in gem varieties such as ruby and sapphire and in a dark-colored variety that is used for polishing and scraping. Corundum is found in igneous and carbonate rocks. Chemical formula: Al2O3.