Grey, Brown, Green, Colorless, White
Colorless, White, gray, Brownish, Greenish
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Micaceous, Brittle
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
KAl 2AlSi 3O 10(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references