ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
SiO 2Walter Schumann , Gemstones of the world (2001)
Al 2(Cl 2O 12) · 18H 2OUlrich Henn and Claudio C.