ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references