ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Splintery, UnevenArthur Thomas, Difficult, Fibrous
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
NaAlSi 2O 6Ulrich Henn and Claudio C.