Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
(Be,Cs) 3Al 2Si 6O 18 · 0.5H 2OUlrich Henn and Claudio C.
LiAl(PO 4)(OH,F)Walter Schumann , Gemstones of the world (2001) More from other references