ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)
(Fe,Mn) 7Si 7O 21Ulrich Henn and Claudio C.