Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Conchoidal, Splintery, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle
(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al) 2O 6Anthony et al , Handbook of mineralogy (2001)
AlPO4 · 2(H2O)