ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)
Fe 2O 3Arthur Thomas , Gemstones (2009)