White, Reddish
Colorless, Colorless, Violet, White
Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.