Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
LiAl(PO 4)(OH,F)Walter Schumann , Gemstones of the world (2001) More from other references
SiCArthur Thomas , Gemstones (2009)