It forms when salty water evaporates, such as sea water. When the evaporation process happens the salt is too heavy and is left behind. People sometimes use it as a form of humane ammunition to drive off unwanted animal and human visitors without hurting them, although a face full of salt can be potentially very dangerous, especially if pellets it get into the eyes. This form of salt is available in most grocery stores and also in hardware stores, which stock it in massive bags for the purpose of keeping down ice on the roads in the winter. exciting challenge of being a wiseGEEK researcher and writer. Rock salt is a large-grained, unrefined salt that usually contains inedible impurities. Salt lowers the freezing point of water, so rock salt has historically been used to salt icy roads in winter to melt the ice away. This form of salt is mined from deposits that form underground. A large amount of the mined rock salt is used for human consumption. Rock salt is the mineral form of sodium chloride, otherwise known as table salt.It's sometimes referred to as “halite,” especially when it is used industrially. It does have one use in cooking: Homemade ice cream recipes often instruct you to sprinkle rock salt on the ice surrounding the cylinder filled with the ice cream mixture. Thanks for your help! Because of the large crystal size, rock salt is not usually used directly in cooking, since it takes a long time to dissolve. When it's packed in with ice in an ice cream maker, it lowers the freezing point, allowing the ice cream to get colder. The salt occurs in beds of sedimentary evaporite minerals. Thanks for any information. The source of all salt is the sea. The primary difference between rock salt and ordinary table salt is the size and colour. Backed up by our experienced in-house technical and sales team, we are confident that we can fulfil your requirements. Rock Salt is a chemical sedimentary rock that forms from the evaporation of ocean or saline lake waters. Like table salt, rock salt also has an assortment of trace minerals which can have an impact on how it behaves chemically. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on inclusion of other materials, impurities, and structural or isotopic abnormalities in the crystals. The primary difference between rock and table salt is the size. Rock salt is used commonly 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, this allows it to not freeze-over zero degrees Celsius. The name halite is derived from the Ancie… If you thought stocks would be depleted any time soon you'll be surprised to learn that the proven UK salt reserves are extensive, with an estimated 500 years capacity at current extraction rates. Deposits of rock salt are usually the remains of inland seas which evaporated thousands or millions of years ago. I do have one more question though. It is rarely found at Earth's surface, except in areas of very arid climate. Winsford is in Cheshire and four of the surrounding towns - Middlewich, Nantwich, Northwich and Leftwich are all historically related to salt production. If it's going to be consumed, cooks should be sure to purchase food-grade rock salt, as some companies treat salt intended for roads and other uses with chemicals. In contrast, table salt comes almost exclusively from evaporation ponds which remove salt from seawater. The formation of rock salt deposits in our oceans is the way that the ocean can regulate the NaCl content and not become too salty.