What is a Ruby?
A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminum oxide). The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, which is Latin for red. Other varieties of gem-quality corundum are called sapphires. The ruby is considered one of the four precious stones, together with the sapphire, the emerald and the diamond.
Prices of rubies are primarily determined by color. The brightest and most valuable "red" called blood-red, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Cut and carat (weight) are also an important factor in determining the price.
Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only moissonite and diamond are harder, with diamond having a Mohs hardness of 10.0 and moissonite falling somewhere in between corundum (ruby) and diamond in hardness.
Prices of rubies are primarily determined by color. The brightest and most valuable "red" called blood-red, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Cut and carat (weight) are also an important factor in determining the price.
Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only moissonite and diamond are harder, with diamond having a Mohs hardness of 10.0 and moissonite falling somewhere in between corundum (ruby) and diamond in hardness.
