ETYM French rubis (cf. Pr. robi), Late Lat. rubinus, robinus, from Latin rubeus red, reddish, akin to ruber. Related to Rouge, red.
1. A transparent deep red variety of corundum; used as a gemstone and in lasers.
2. A transparent piece of ruby that has been cut and polished and is valued as a precious gem.
The red transparent gem variety of the mineral corundum Al2O3, aluminum oxide. Small amounts of chromium oxide, Cr2O3, substituting for aluminum oxide, give ruby its color. Natural rubies are found mainly in Myanmar (Burma), but rubies can also be produced artificially and such synthetic stones are used in lasers. + prikaži više