Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
Ca 9(Mg,Fe2+ )(PO 4) 6(PO 3OH)Anthony et al , Handbook of mineralogy (2001)
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references