Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Red, Brown, Brown, Red, Yellow, pink
Uneven
UnevenArthur Thomas, Gemstones (2009) Tough, UnevenArthur Thomas, Gemstones (2009) Tough, Brittle, Uneven
Na 3AlF 6Ulrich Henn and Claudio C.
Mn 8Si 6O 15(OH,Cl) 10Ulrich Henn and Claudio C.