Unrefined salts have long been the darling of some gourmet cooks and up-scale restaurants because of the subtle differences in taste from refined table salt. However, "raw" salts are being touted as better for horses' health with a range of claims being made, including that your familiar white salt block or table salt is harmful or inadequate.
What is salt?
Salt is a chemical composed of one molecule of sodium and one molecule of chlorine-sodium chloride, or NaCl.
Halite is another term for salt in its natural form in mineral deposits on land. Halite forms in areas where ancient seas or salt lakes evaporated, and is the material retrieved during salt mining. Halite deposits are most often contaminated with other "evaporite" salts, chemicals that tend to precipitate out at near the same concentration that makes salt crystals. These include gypsum (calcium sulfate) sylvite (potassium chloride) and carnalite (potassium magnesium chloride).
All salt, whether on land or in the sea, originated from seas. Salt deposits found on land are at the site of previous sea beds or salt lakes that formed due to continental shifts. They remained after water evaporated.
The salt deposits become buried but tend to migrate toward the surface. These inland salt deposits are found on every continent, often in close association with oil or natural gas.
What's wrong with processed salt?
In a nutshell - nothing. Salt processing, which basically involves the removal of contaminating minerals, was begun to provide as pure a salt as possible for research and industrial uses and to make the salt more suitable for use in processed foods. Too much calcium in salt makes vegetables tough when they are cooked. Iron in natural salt deposits will cause loss of antioxidant vitamins and accelerate fats going rancid in stored foods/feeds. Sulfate salts produce an unpleasant smell and taste.
The criticism leveled at "processed" salt comes on several fronts. One is that "chemicals" are used to manufacture it. Salt is a chemical. All the other compounds found in raw salts are chemicals.
There are salt-purification methods that actually don't use additional chemicals at all, just heat and repeated washings with pure water, to produce a 99+% pure salt. Others use chemicals (other minerals) to make the contaminating minerals in salt precipitate and settle out. These do not remain in the final cleaned salt product.
"Chemical additives" is another common scare tactic. Iodine, a nutritionally essential mineral, is added to some salts. You can purchase salt with or without iodine. Horses need iodine as much as people do, though. Unless the diet is composed of things grown close to the ocean, iodine will be deficient in most equine diets. Other additives in table salt are present in low amounts. Their purpose is to keep the salt free flowing and inhibit moisture absorption to some extent. These include various calcium or magnesium salts, and silicates. All of these things are nontoxic and are present in the environment naturally. Your horse would get far more of them from a mouthful of dirt than 1 or 2 oz. of salt.
