Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
Uneven, Uneven, Gemstones of the world (2001) More from other references
ThCa 2Si 8O 20Walter Schumann , Gemstones of the world (2001) More from other references
Ca 10Mg 2Al 4(SiO 4) 5(Si 2O 7) 2(OH) 4Ulrich Henn and Claudio C.