Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Splintery, UnevenArthur Thomas, Difficult, Fibrous
LiAl(PO 4)(OH,F)Walter Schumann , Gemstones of the world (2001) More from other references
NaAlSi 2O 6Ulrich Henn and Claudio C.