Colorless, Yellow, Brown, Green, Colorless, Green, Yellow, Red, Reddish, Brown
Green, Black, White, Grey, Green, Black, White, Grey, Green, Black, gray, Black, Green, Black, gray, Black
Brittle, Metallic, Brittle, Metallic
Uneven, UnevenArthur Thomas, Gemstones (2009), Splintery
Ca(Mg,Al)3(Al3Si)O10(OH)2
Ca 2(Mg,Fe) 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.