Определение corundum в Английский Язык Английский Язык словарь
an extremely hard mineral, a form of aluminium oxide with the chemical formula Al2O3, that occurs in the form of the gemstones ruby and sapphire; it is used as an abrasive
Corundum (aluminum oxide Al2O3) is the hardest mineral other than diamond, though only 1/140 as hard Red corundum is ruby, other colors are called sapphires There is no clear demarcation of color to define which gems are called rubies or sapphires Light red, pink or violet corundums are usually classified as sapphires with the name ruby reserved for truly red stones The coloring in ruby comes from chrome, pigment in blue sapphire is iron and titanium, and in violet stones, vanadium Iron content causes yellow and green tones A R T Precious & Collectible Jewelry
an extremely hard mineral, a form of aluminium oxide, that occurs in the form of the gemstones ruby and sapphire; it is used as an abrasive
Aluminum oxide mineral (Al2O3) that is, after diamond, the hardest known natural substance. Gem varieties are sapphire and ruby; mixtures with iron oxides and other minerals are called emery. Corundum is widespread in nature, although large deposits are rare. Rich deposits occur in India, Russia, Zimbabwe, and South Africa. In addition to being a precious gem, corundum is used as an abrasive for grinding optical glass and for polishing metals and has also been made into sandpapers and grinding wheels. For most industrial applications, however, it has been replaced by synthetic materials such as alumina; synthetic corundum is also manufactured
The earth alumina, as found native in a crystalline state, including sapphire, which is the fine blue variety; the oriental ruby, or red sapphire; the oriental amethyst, or purple sapphire; and adamantine spar, the hair-brown variety
A hard mineral that exists in the form of colored crystals, such as rubies and sapphires
corundum
Расстановка переносов
co·run·dum
Турецкое произношение
kırʌndım
Произношение
/kərˈəndəm/ /kɜrˈʌndəm/
Этимология
[ k&-'r&n-d&m ] (noun.) 1804. Tamil kuruntam; akin to Sanskrit kuruvinda ruby.