White, Reddish, gray, Brown, Brownish
White, Colorless, Blue, Red, Green, Yellow, Violet
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Not Available
Na 3(Na,K)Al 4Si 4O 16Ulrich Henn and Claudio C.
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)