Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.
(Mg,Fe2+ ) 7(SiO 4) 3(F,OH) 2Anthony et al , Handbook of mineralogy (2001)