Tags: Chemical Substance, Mineral.
Grandreefite is a rare secondary lead sulfate-fluoride mineral with a general chemical formula Pb2SO4F2. It is named for the location in which it was discovered in 1989 the Grand Reef Mine in Graham County Arizona. Grandreefite is monoclinic falling in the 2/m symmetry group. Crystallographically this means grandreefite has three axes of unequal length with two angles at 90° to one another and a third obtuse angle.