Uneven, Uneven, Gems, Sixth Edition (2006)
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Al 2O 3Michael OâDonoghue , Gems, Sixth Edition (2006)
Al 2(Cl 2O 12) · 18H 2OUlrich Henn and Claudio C.