Sea salt has become widely believed to be healthier than regular table salt, but is that really the case? They both have the same basic components, sodium and chloride. The main difference between the two are their taste, texture, and processing. Sea salt is produced through the evaporation of seawater which leaves behind trace minerals and elements depending on its water source. These insignificant amounts of minerals add flavor, colort, and coarseness. On the other hand, table salt is mined from underground salt deposits. It is more heavily processed to eliminate trace minerals and usually contains an additive to prevent clumping. It also has added iodine, an essential nutrient that appears naturally in small amounts in salt.
Since the underground salt deposits that produce most table salt are the result of evaporating seawater or salty lakes, you would think the chemistry would be pretty much the same, and mostly it is. Both rock salt (salt from mines that make table salt) and sea salt contain, besides sodium chloride, such chemicals as calcium, potassium, and magnesium sulfates. However, when a large body of water evaporates, the chemicals in it precipitate out in stages – calcium compounds get deposited first, then sodium, and finally magnesium and potassium. Because of this, a rock salt deposit is often a more homogenous mass of sodium chloride than what you get by drying out seawater commercially. Since rock salt is destined for human consumption it is typically processed to remove grit and other impurities, by the time it reaches the salt shaker it is nearly pure sodium chloride.
Overall, sea salt is considered healthier because it is less refined and therefore contains more traces of healthy minerals such as iron, calcium, zinc and iodine. It goes through very little processing. Its impurities are a big selling point, and frequently they are its identifying mark. It is the tiny bits of clay that give gray sea salt its color, and it is the iron-rich red volcanic clay added to Hawaiian sea salt that gives it its red color.
On the other hand, table salt is put through a chemical treatment process which is typically fortified with iodine. Many people worry that sea salt does not contain sufficient amounts of iodine, since it is not fortified the way table salt is. However, sea salt does contain amounts of naturally occurring iodine. It is just not as much as you would find in iodized table salt. If your diet does not contain other sources of iodine, you may not want to make the switch, but otherwise sea salt may be a good choice for you.