Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
CaBePO 4(F,OH)Ulrich Henn and Claudio C.
SiO 2Ulrich Henn and Claudio C.