ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
MgAlBO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)