Salt is a dietary mineral composed primarily of sodium chloride that is essential for animal life, but toxic to most land plants. Salt flavor is one of the basic tastes, an important preservative and a popular food seasoning.
Salt for human consumption is produced in different forms: unrefined salt (such as sea salt), refined salt (table salt), and iodized salt. It is a crystalline solid, white, pale pink or light gray in color, normally obtained from sea water or rock deposits. Chloride
and sodium ions, the two major components of salt, are necessary for the survival of all known living creatures, including humans. Salt is involved in regulating the water content (fluid balance) of the body. Salt cravings may be caused by trace mineral deficiencies as well as by a deficiency of sodium chloride itself.
Sea salt, Halite, and Fleur de sel
Different natural salts have different mineralities, giving each one a unique flavor. Fleur de sel, natural sea salt harvested by hand, has a unique flavor varying from region to region.
￼￼Refined salt, which is most widely used presently, is mainly sodium chloride. All the minerals are taken out for medicinal and other purposes.
Food grade salt accounts for only a small part of salt production..
The majority is sold for industrial use. Salt has great commercial value because it is a necessary ingredient in the manufacturing of many things. A few common examples include: the production of pulp and paper, setting dyes in textiles and fabrics, and the making of soaps and detergents.
The manufacture and use of salt is one of the oldest chemical industries. Salt can be obtained by evaporation of sea water, usually in shallow basins warmed by sunlight; Today, most refined salt is prepared from rock salt: mineral deposits high in salt.These rock salt deposits were formed by the evaporation of ancient salt lakes, and may be mined conventionally or through the injection of water. Injected water dissolves the salt, and the brine solution can be pumped to the surface where the salt is collected.
After the raw salt is obtained, it is refined to purify it and improve its storage and handling characteristics. Purification usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most impurities (largely magnesium and calcium salts). Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are kiln-dried.
Fleur de sel
Fleur de sel ("Flower of salt" in French) is a hand-harvested sea salt collected by workers who scrape only the top layer of salt before it sinks to the bottom of large salt pans. Traditional French fleur de sel is collected off the coast of Brittany (most notably in the towns of Guérande - Fleur de Sel de Guérande, hand harvested from salt marsh water being the most revered), Noirmoutier, and also Camargue. It is often slightly grey due to the sandy minerals collected in the process of harvesting the salt from the pans. On occasion, the presence ofDunaliella salina (a type of pink micro-algae commonly found in salt marshes) can give it a light pink tint. Due to its relative scarcity, Fleur de sel is one of the more expensive salts. It is usually sold in airtight jars as it is slightly damp
The Portuguese variant "flor de sal" from the Algarve is of similar quality but is pure white and usually sells for half the price of the French fleur de sel.
Due to the small size of the crystals, fleur de sel dissolves faster than regular salt. Hence it is best used similarly to fresh herbs, sprinkling it onto food just before serving.
Pink Salt is a rock salt mined in several parts of the world, including Hawaii, Bolivia, theMurray-Darling basin of Australia, Peru, Pakistan (?Himalayan salt), and Poland. The color results from iron oxide.
Unfortunately, table salt contains ingredients other than sodium and chlorine—aluminum, for one. Two of the most common anticaking agents used in salt production are sodium alumino-silicate and alumino-calcium silicate. Aluminum is a toxic metal that has been linked to Alzheimer's disease and in any case has no place in a healthy diet.
Table salt without aluminium is available. I use organic sea salt, which slightly gray and moist. For my home made herb salt I use aluminium free refined sea salt, as this is easy to mix the dried herbs into it.
some excerpts courtesy Wikipedia.