ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Conchoidal, Conchoidal, Gemstones of the world (2001)
Al 2(Cl 2O 12) · 18H 2OUlrich Henn and Claudio C.
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001) More from other references