Dead Sea salt
Dead Sea salt refers to salt and other mineral deposits extracted or taken from the Dead Sea. The composition of this material differs significantly from oceanic salt.
History
Dead Sea salt was used by the peoples of Ancient Egypt and it has been utilized in various unguents, skin creams, and soaps since then.Mineral composition
The Dead Sea's mineral composition varies with season, rainfall, depth of deposit, and ambient temperature. Most oceanic salt is approximately 85 wt.% sodium chloride while Dead Sea salt is only 30.5 wt.% of this, with the remainder composed of other dried minerals and salts. The extreme salinity of the Dead Sea is due to rapid evaporation and the absence of an outlet, leading to a high concentration of minerals such as magnesium, sodium, and potassium. These minerals are continuously deposited as water evaporates, making the Dead Sea one of the saltiest bodies of water on Earth. The concentrations of the major ions present in the Dead Sea water are given in the following table:| Ion | Concentration |
| Chloride and Bromide | 230.4 |
| Magnesium | 45.9 |
| Sodium | 36.6 |
| Calcium | 17.6 |
| Potassium | 7.8 |
The chemical composition of the crystallized Dead Sea salts does not necessarily correspond to the results presented in this table because of composition changes due to the process of fractional crystallization.
The main detritic minerals present in the Dead Sea mud were carried by runoff streams flowing into the Dead Sea. They constituted large mud deposits intermixed with salt layers during the Holocene era. Their elemental composition expressed as equivalent oxides is given here below:
| Mineral* | Content |
| Silicon dioxide | 20 |
| Calcium oxide | 15.5 |
| Aluminum oxide | 4.8 |
| Magnesium oxide | 4.5 |
| Iron(III) oxide | 2.8 |
| Sodium oxide | 1.7 |
| Potassium oxide | 1.3 |
| Titanium(IV) oxide | 0.5 |
| Sulfur trioxide | 0.4 |
| Phosphorus pentoxide | 0.3 |
| Chloride | 6.7 |
| Bromide | 0.2 |
Except for chloride and bromide, the results of the elemental composition of the Dead Sea mud given here above are presented as equivalent oxides for the sake of convenience. To illustrate this chemical convention, the neutral sodium sulfate is reported here as basic sodium oxide and acidic sulfur trioxide, neither of which can naturally occur under these free forms in this mud. However, one will note that the elemental composition given here above is incomplete as a major component is lacking in this table: carbon dioxide accounting for the significant carbonate fraction present in this mud.