UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
ConchoidalArthur Thomas, Gemstones (2009)
CaMoO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Tourmaline is a series of several different minerals with unique chemical formulas.