ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Al 2(Cl 2O 12) · 18H 2OUlrich Henn and Claudio C.
Fe 2O 3Arthur Thomas , Gemstones (2009)