Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Al 2(Cl 2O 12) · 18H 2OUlrich Henn and Claudio C.