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.
SiO 2Ulrich Henn and Claudio C.