Sapphire, like ruby, is a variety of corundum; it gains its color from one or more metallic oxides that appear in the mineral as impurities. The Lone Star, a star sapphire cut in England in 1889, weighs 9,719.5 carats, or about four and a half pounds. Class: precious Origin of Name: from the Latin sapphirus (blue) Color: blue, white, yellow, orange, green, purple, pink Chemical Composition: aluminum oxide Crystal System: trigonal Hardness: 9 Specific Gravity: 3.96-4.05 Geographic Origins: Kashmir (India), Sri Lanka, Burma, Australia, Montana, North Carolina Next Photo: ©International Colored Gemstone Association The Science Behind the Sparkle | Diamonds in the Sky A Primer of Gemstones | See Inside a Diamond Resources | Transcript | Site Map | Diamond Deception Home Editor's Picks | Previous Sites | Join Us/E-mail | TV/Web Schedule About NOVA | Teachers | Site Map | Shop | Jobs | Search | To print PBS Online | NOVA Online | WGBH © | Updated November 2000