Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references