Colorless, Colorless, Violet, White
Blue
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.
Be 3Al 2Si 6O 18Ulrich Henn and Claudio C.