Gems, Sixth Edition (2006), Gems, Sixth Edition (2006), Uneven
Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
Na(90-70%)Ca(10-30%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)