Uneven, Brittle, Uneven, Brittle, Uneven
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
(K,Na)Ca4Si8O20(F,OH)•8(H2O)
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)