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: 1720–30; < Tamil kuruntam; akin to Skt kuruvinda ruby
Main Entry: co·run·dum Pronunciation: k&-'r&n-d&m Function: noun : a very hard mineral Al2O3 that consists ofalumina occurring in massive form and as variously colored crystals which include the ruby and sapphire
[kuh-ruhn-duh
m] 
