Pakistan, Italy, Russia, China, Brazil, Switzerland, Madagascar, Austria, Canada
Afghanistan, Pakistan, Burma, Brazil, Madagascar, USA, Canada, Russia, Madagascar, Brazil, Canada, Mexico, Madagascar, Brazil, Canada, Mexico
Reddish, Brown, Yellow, Green, Red, gray
Colorless, pink
Sub-Conchoidal, Conchoidal, Brittle
Gemstones of the world (2001), UnevenWalter Schumann, Gemstones of the world (2001)
Strong: X = nearly colorless; Y = yellow to green; Z = red to yellow-orange
Strong trichroism: colorless pink violetHerve Nicolas Lazzarelli