corundum

[ kuh-ruhn-duh m ]

/ kəˈrʌn dəm /

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.

Nearby words

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

Examples from the Web for corundum

Copper ore is found in many tracts throughout India, plumbago in Madras, and corundum in southern India.
Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 4|Various
Corundum is a mineral similar to emery, and corundum wheels are made and used in the same manner as emery wheels.
Modern Machine-Shop Practice, Volumes I and II|Joshua Rose
Canadian corundum occurs as a constituent of syenite and nepheline-syenite in Lower Ontario.
The Economic Aspect of Geology|C. K. Leith
It is interesting to note that the corundum gems undergo marked change in color under the influence of radium.
A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public|Frank Bertram Wade

While Corundum of all colors is used for gems, it is only that which is transparent which can be so employed.
Birds and Nature, Vol. 12 No. 5 [December 1902]|Various

British Dictionary definitions for corundum

corundum

/ (kəˈrʌndəm) /

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

corundum

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

Science definitions for corundum

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.