White, Colorless, Blue, Red, Green, Yellow, Violet, pink
Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Uneven
(Be,Cs) 3Al 2Si 6O 18 · 0.5H 2OUlrich Henn and Claudio C.
Na 3AlF 6Ulrich Henn and Claudio C.