Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
Uneven, UnevenArthur Thomas, Gemstones (2009)
ThCa 2Si 8O 20Walter Schumann , Gemstones of the world (2001) More from other references
Mg 3Si 4O 10(OH) 2Ulrich Henn and Claudio C.