Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Metallic
Uneven, Uneven, Gems, Sixth Edition (2006)
CuSMichael OâDonoghue , Gems, Sixth edition (2006) More from other references
CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)