Blue, Grey
Colorless, Reddish, White, pink, Green, Yellow, Violet, White, pink, Green, Yellow, Violet, White, Colorless, Blue, Green, Brown, Yellow, pink, Violet, White, pink, Green, Yellow, Violet
Gemstones of the world (2001)
Uneven, UnevenArthur Thomas, Gemstones (2009)
SiO 2Walter Schumann , Gemstones of the world (2001)
KCa 4Si 8O 20(F,OH) · 8H 2OUlrich Henn and Claudio C.