UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001), Uneven
ConchoidalArthur Thomas, Gemstones (2009)
Fe3+ PO 4 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)
Tourmaline is a series of several different minerals with unique chemical formulas.