ConchoidalArthur Thomas, Gemstones (2009)
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Tourmaline is a series of several different minerals with unique chemical formulas.
Al 2(Cl 2O 12) · 18H 2OUlrich Henn and Claudio C.