Splintery, Brittle, Uneven
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
NaCa 2(Mg 4Al)Si 6Al 2O 22(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
3CaAl 2Si 2O 8 · CaCO 3Anthony et al , Handbook of mineralogy (2001)