Uneven, UnevenArthur Thomas, Gemstones (2009), Brittle
Uneven, Uneven, Gemstones of the world (2001) More from other references
MnPO 4Walter Schumann , Gemstones of the world (2001) More from other references
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references