Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Yellow, Brown, gray, Greenish
Uneven
Uneven, Conchoidal, UnevenArthur Thomas, Brittle
Na 3AlF 6Ulrich Henn and Claudio C.
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references