Subconchoidal, Uneven, Conchoidal, Uneven
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)