Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
Splintery, Granular, Splintery, Granular, Gemstones (2009)
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references