Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Al 6B 5O 15(F,OH) 3Ulrich Henn and Claudio C.
SiO 2 + H 2OUlrich Henn and Claudio C.