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 2(+Al 2O 3)Walter Schumann , Gemstones of the world (2001)