Grey, Brown, Green, Colorless, White
White, Colorless, Blue, Red, Green, Yellow, Violet
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Not Available
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)