Uneven, Uneven, Gemstones of the world (2001) More from other references
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.