Brittle, Uneven, Brittle, Uneven
Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
NaCa16Si23AlO60(OH)8•64(H2O)
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)