Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
Uneven, Uneven, Management Team (2012), Conchoidal, Brittle
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)
Fe 3O 4Ulrich Henn and Claudio C.