Colorless, Colorless, Violet, White
Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.
Na 3AlF 6Ulrich Henn and Claudio C.