ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalGemdat.org, Management Team (2012)
(Ca,Cr)MgSi 2O 6Gemdat.org , Management Team (2012)
Mg 3Al 2(SiO 4) 3 -Mn2+3Al 2(SiO 4) 3Gemdat.org , Management Team (2012)