Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Ca 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
CaTiSiO 5Ulrich Henn and Claudio C.