Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Colorless, Blue, Violet, White, Brown, Colorless, Blue, Violet, White, rose, Brown, gray, Colorless, White, Violet, gray, Colorless, White, Violet, gray
Uneven
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Na 3AlF 6Ulrich Henn and Claudio C.
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references