Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Metallic
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
CuSMichael OâDonoghue , Gems, Sixth edition (2006) More from other references
BaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references