ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
SiO 2 + H 2OUlrich Henn and Claudio C.
Al 2SiO 5Arthur Thomas , Gemstones (2009)