Rubies, like sapphires, are a variety of the mineral corundum, which is known for its remarkably rich color. The Eminent Star ruby, the largest known, weighs 6,465 carats, or almost three pounds.

Class: precious
Origin of Name: from the Latin ruber (red)
Color: red, orange-red, purple-red
Chemical Composition: aluminum oxide
Crystal System: trigonal
Hardness: 9
Specific Gravity: 3.96-4.05
Geographic Origins: Burma, Thailand, Cambodia, Kenya, Tanzania, Zimbabwe

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Photo: ©International Colored Gemstone Association

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