Colorless, Colorless, Violet, White
Black
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.
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)