Splintery, Granular, Splintery, Granular, Gemstones (2009)
Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)