Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Colorless, White, Brown, Green, Greenish, gray
Uneven
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Na 3AlF 6Ulrich Henn and Claudio C.
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references