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