Uneven, Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven, Subconchoidal, Brittle, Metallic, Brittle, Metallic
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)
Ca 2 MgAl 2 BSi 4 O 15 OH Gemdat.org, Management Team (2012)