Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Ca 9(Mg,Fe2+ )(PO 4) 6(PO 3OH)Anthony et al , Handbook of mineralogy (2001)
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.