Many of these minerals are water-soluble and are often found in arid areas in crusts and other deposits as are various borates, nitrates, iodates, bromates and the like. Others, such as the fluorite group, are not water-soluble. As a collective whole, simple halide minerals (containing fluorine through iodine, alkali metals, alkaline Earth metals, in addition to other metals/cations) occur abundantly at the surface of the Earth in a variety of geologic settings. More complex minerals as shown below are also found.
Commercially significant halide mineralsEdit
Two commercially important halide minerals are halite and fluorite. The former is a major source of sodium chloride, in parallel with sodium chloride extracted from sea water or brine wells. Fluorite is a major source of hydrogen fluoride, complementing the supply obtained as a byproduct of the production of fertilizer. Carnallite and bischofite are important sources of magnesium. Natural cryolite was historically required for the production of aluminium, however, currently most cryolite used is produced synthetically.
Many of the halide minerals occur in marine evaporite deposits. Other geologic occurrences include arid environments such as deserts. The Atacama Desert has large quantities of halide minerals as well as chlorates, iodates, oxyhalides, nitrates, borates and other water-soluble minerals. Not only do those minerals occur in subsurface geologic deposits, they also form crusts on the Earth's surface due to the low rainfall (the Atacama is the world's driest desert as well as one of the oldest at 25 million years of age).
^ abcSorrel, Charles A., Rocks & Minerals (originally Minerals of the World), Chapter "Halides", pp. 118–127, 1973, St Martin's Press: NYC · Racine, WI, ISBN 1-58238-124-0.
Stuart J. Mills; Frédéric Hatert; Ernest H. Nickel; Giovanni Ferraris (2009). "The standardisation of mineral group hierarchies: application to recent nomenclature proposals" (PDF). Eur. J. Mineral. 21 (5): 1073–1080. doi:10.1127/0935-1221/2009/0021-1994.
Ernest H. Nickel; Monte C. Nichols (March 2009). "IMA-CNMNC List of Mineral Names" (PDF). IMA-CNMNC.