ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Ca 5(F,Cl)(PO 4) 3Arthur Thomas , Gemstones (2009)
SiO 2Ulrich Henn and Claudio C.