Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Ca 2 MgAl 2 BSi 4 O 15 OH Gemdat.org, Management Team (2012)
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)