UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)