Sodium chloride (salt) is the chemical compound NaCl. Composed of the elements sodium and chloride it is one of the most basic molecules on earth. Salt is so simple and plentiful that we almost take it for granted. Approx. 68% of the world's surface is covered by the world's oceans and seas. Ocean water is approx. 3.5% salt concentration. That means that if the oceans dried up completely, enough salt would be left behind to build a 180-mile-tall, one-mile-thick wall around the equator!
Salt also occurs naturally in many parts of the world as the mineral halite (rock salt).
There are three basic types of salt: rock salt, evaporated salt and solar salt
Deep underground deposits are conventionally mined by drilling and blasting to produce rock salt.
Salt water, or brine, is boiled under a partial vacuum with steam heat, in enclosed vessels called vacuum pans. The brine is purified and fed to large evaporators where salt crystallizes in to granulated salt.
Solar salt is produced through the natural evaporation of sea water. Salt water is captured in shallow ponds and allowed to evaporate by means of the sun and wind. The typical solar crop takes from one to five years to produce.
Virtually all food grade salt sold or used in the United States is produced by vacuum evaporation of brine. However, prior to mechanical evaporation, the brine may be treated to remove minerals that can cause scaling in the evaporators. Chemical treatment of the brine, followed by settling, reduces levels of dissolved calcium, magnesium and sulfate.
In addition, these are the very minerals we want our body to absorb when we bath in bath salts. That's why here at the San Francisco Bath Salt Company we only use pure, unadulterated solar salt.
Purity of salt produced in North America varies depending on the type of salt the source. Rock salt typically ranges between 95% and 99% NaCl, and mechanically evaporated salt and solar salt normally exceed 99% NaCl. The principal other ingredients in solar salt are calcium and magnesium sulfate, and magnesium chloride.
Here at the San Francisco Bath Salt Company we only use natural solar salts that retain as much of the natural minerals as possible.
Our salt comes from a long tradition of salt making along the shores of the San Francisco Bay, using sunlight and wind to slowly concentrate and crystallize the natural salt carried by the Bay's waters.