Evaporite

Evaporites are sediments that result from the evaporation of saline water. Most evaporites are derived from bodies of sea-water, though saline lakes may also be an important source (e.g. the Great Salt Lake, Utah).

Evaporites start to precipitate when their concentration in water reaches such a level that they can no longer exist as solutes. They precipitate out of solution in the reverse order of their solubilities, such that the order of precipitation is:

1. Calcite (CaCO₃) and dolomite (CaMg(CO₃)₂)
2. Gypsum (CaSO₄) and anhydrite (CaSO₄.2H₂O)
3. Halite (i.e. common salt, NaCl)
4. Potassium and magnesium salts

See also

• List of minerals