ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
(Ca,Mg,Mn)SiO 3Gemdat.org , Management Team (2012)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.