Dragi kamen crvene boje, vrsta korunda; proziran, veoma tvrd (lat.)
Proziran crveni dragi kamen, pored dijamanta najtvrđi. Mg Al2 O4.
A dark-colored spinel containing iron; Also called: pleonaste.
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.
ETYM French spinelle, or Late Lat. spinellus, perhaps from Latin spina a thorn, a prickle, in allusion to its pointed crystals.
A hard glassy mineral consisting of an oxide of magnesium and aluminum; occurs in various colors that are used as gemstones.
rubylike precious stone.
Any of a group of “mixed oxide” minerals consisting mainly of the oxides of magnesium and aluminum, MgAl2O4 and FeAl2O4. Spinels crystallize in the cubic system, forming octahedral crystals. They are found in high-temperature igneous and metamorphic rocks. The aluminum oxide spinel contains gem varieties, such as the ruby spinels of Sri Lanka and Myanmar (Burma).