ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
(Ca,Mg,Mn)SiO 3Gemdat.org , Management Team (2012)
Mg 2Si 2O 6Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references