Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
LiAl(PO 4)(OH,F)Walter Schumann , Gemstones of the world (2001) More from other references
Na 3(Na,K)Al 4Si 4O 16Ulrich Henn and Claudio C.