Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Uneven, UnevenAnthony et al, Handbook of mineralogy (2001)
(Be,Cs) 3Al 2Si 6O 18 · 0.5H 2OUlrich Henn and Claudio C.
Pb 5Cu 2(SO 4) 3(CO 3)(OH) 6Anthony et al , Handbook of mineralogy (2001)