Uneven, Conchoidal, UnevenArthur Thomas, Brittle
Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Metallic
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
CuSMichael OâDonoghue , Gems, Sixth edition (2006) More from other references