ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Be 3Al 2Si 6O 18Ulrich Henn and Claudio C.
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)