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