As allochromatic (other colored) gems, rubies' colors are due to trace elements. apart from their color, the gems are identical to sapphires and are comprised of corundum. Corundum is the crystalline form of aluminum oxide. Its name is believed to be derived from three ancient Tamil, Hindi, and Sanskrit words for rubies and sapphires: kurundam, kurund, or kuruvinda, respectively.
Vietnamese Star, Burmese, Madagascan, Mahaleo
Ruby |
July's Birthstone |
Major Sources |
Afghanistan, Burma, Cambodia, India, Kenya, Madagascar, Sri Lanka, Tajikistan, Tanzania, Thailand, & Vietnam |
Colors Found |
Red |
Family |
Corundum: Al2O3 |
Hardness |
9.00 |
Refractive Index |
1.76 - 1.78; Uniaxial (-) |
Specific Gravity |
3.97 - 4.05 |
Crystal System |
Trigonal |
©2011 America's Collectibles Network Inc. ♦ Gerald D. Sisk, JR. ♦ Guide to Gems & Jewelery ♦ Jewelry Television™