ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Mg 3(Al,Cr) 2(SiO 4) 3Gemdat.org , Management Team (2012)
SiO 2 + H 2OUlrich Henn and Claudio C.