Uneven, Conchoidal, Brittle
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)