Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
UnevenArthur Thomas, Gemstones (2009) Tough, UnevenArthur Thomas, Gemstones (2009) Tough, Brittle, Uneven
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)
Mn 8Si 6O 15(OH,Cl) 10Ulrich Henn and Claudio C.