Halide minerals are those minerals with a dominant halide anion (, , and ). Complex halide minerals may also have polyatomic anions.
Examples include the following:
Atacamite
Avogadrite (K,Cs)BF
Bararite (β)
Bischofite
Brüggenite
Calomel
Carnallite
Carnallite
Cerargyrite/Horn silver AgCl
Chlorargyrite AgCl, bromargyrite AgBr, and iodargyrite AgI
Cryolite
Cryptohalite (a)
Dietzeite
Eglestonite
Embolite AgCl+AgBr
Eriochalcite
Fluorite
Halite NaCl
Lautarite
Marshite CuI
Miersite AgI
Nantokite CuCl
Sal Ammoniac
Sylvite KCl
Terlinguaite
Tolbachite
Villiaumite NaF
Yttrocerite (Ca,Y,Ce)F2
Yttrofluorite (Ca,Y)F2
Zavaritskite (BiO)F
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.
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.