Rock salt-This is the common name for the mineral "halite". Its chemical formula is NaCl. Most of us know this substance as table salt. and... Actually, rock salt is not K2SO4; it is NaCl. It can have impurities of gypsum (CaSO4) and sylvite (KCl) but it is very rare to find potassium sulfate as a mineral, although occasionally polyhalite (K2Ca2Mg(SO4)4.2H2O) is found associated with rock salt deposits. It is typically formed by the evaporation of salty water (such as sea water) which contains dissolved Na+ and Cl- ions. Table salt is essential for human life. A large amount of the comercially mined rock salt is prepared for human consumption. Rock salt is also applied to road beds in cold climates to help reduce the freezing point of water on the road, thereby allowing it to not freeze-over at 0 deg. C
Sea salt-, obtained by evaporating seawater, is used in cooking and cosmetics. Historically called bay salt, its mineral content gives it a different taste from table salt, which is pure sodium chloride, usually refined from mined rock salt (halite) or from sea salt.
Sea salt and table salt have the same nutritional value. The real differences between sea salt and table salt are in their taste and texture.
Sea salt is harvested from seawater through evaporation. Table salt is typically from rock salt, which is mined from mineral deposits. Both types of salt can be fully refined, and the end result is pure sodium chloride. Variations in the refining process result in different forms of salt.
Table salt is a fine-grained salt that often contains added iodine (iodized salt). Iodine is necessary for normal thyroid function. Some table salt may also contain anti-caking ingredient.
Sea salt is available in fine or coarse grain. Sea salt has a slightly different taste than table salt because of different minerals it contains. Many people prefer sea salt to table salt because they claim it has a more subtle flavor. Sea sat doesn't contain iodine or any other additives. However, if you use sea salt you typically don't have to worry about not getting enough iodine in your diet because iodine is available in many other foods, including dairy products, seafood and many processed foods.