Switzerland
Canada, Mexico, Brazil, Tanzania, Madagascar, Sri Lanka
Colorless, Yellow, Blue, Reddish, Black, Reddish, Brown, Blue, gray, Black, Reddish, Brown, Blue, gray
Yellow, Red, Brown, yellowish orange
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Not Available