Ohio State Mineral
Salt/Halite STATUS Unofficial DESCRIPTION Salt, or sodium chloride, is composed of 40 percent sodium and 60 percent chlorine by weight. Salt occurs naturally in the oceans, the world’s largest salt resource. Although salt was once considered to be as precious as gold, today it is one of the most commonly available minerals on Earth, used by all cultures. However, salt means different things to different people. Chemically, salt is a generic term given to any one class of similar compounds formed when all or part of the hydrogen ions of an acid are replaced with a metal or metallic radical. Mineralogically, salt is known as halite. The mineral is typically colorless or white when pure, but can be red, yellow, orange, pink, green, blue, violet, or gray. STATE SYMBOL Salt is abundant in the subsurface of northern Ohio. Two salt mines 1,700 feet (518.2 m) beneath Lake Erie produce a total of 4.8 million tons of salt per year and supply much of Ohio with road salt. Although Ohio does not have an official mineral, halite represents the state’s geology and economy well. NAME ORIGIN The word "halite" comes from the Greek word alati meaning "salt." It was later modified to halite by J.D. Dana, a mineralogist, geologist, zoologist, and author of Manual of Mineralogy and Manual of Geology. FORMATION AND OCCURRENCE Halite is found dissolved in the world’s oceans and saltwater lakes. It is typically found in beds in sedimentary rock. It occurs as the remains of dried, ancient seas called salt flats, is found underground in sedimentary rock formations, and arrives on earth in meteorites. GEOGRAPHIC DISTRIBUTION Halite is extremely common. Almost every nation has some sort of salt resource. Some examples of well-studied deposits are listed below. Austria: Hallstadt, Salzburg; and Hall, near Innsbruck, Tirol Switzerland: Bex, Vaud Germany: Stassfurt-Leopoldshall, south of Magdeburg, Saxony-Anhalt Poland: Wieliczka (Galicia) and Bochnia Italy: Girgenti and Racalmuto, Sicily India: Salt Range, Punjab United States: Michigan Basin, underlying Ohio, Michigan, and New York; numerous salt domes along the Gulf Coast; Permian Basin of Texas and New Mexico; Potash Corporation of America mine, Carlsbad potash district, Eddy County, New Mexico USES All life, including humans, came from the sea, and salt is literally part of all organisms. It is essential to human and animal function. Salt helps muscles contract, blood circulate, and hearts beat. Fortunately, there is a limitless supply. In Roman times, salt was extremely valuable and was used as currency. Today, salt is a large-volume, low-priced bulk commodity that is internationally produced and traded. The United States was only recently surpassed by China as the largest salt-producing country in the world. Non-native Americans learned "salt-making" techniques from Indians in the mid-18th century. Salt has been used to preserve food for thousands of years. Salt’s medical, chemical, industrial, and household uses are innumerable. It is used to prepare sodium hydroxide, soda ash, caustic soda, hydrochloric acid, chlorine, and metallic sodium. Salt is water-soluble and an excellent conductor of heat. It is used in ceramics, photography, metallurgy, hide curing, soap manufacturing, fire extinguishers, and numerous cleaning and cooking applications. Rock salt is sometimes referred to as halite, although rock salt is actually a rock and halite a mineral. Rock salt is composed of 95 to 99 percent halite, with the remainder made of impurities of gypsum, dolomite, pyrite, or quartz. The famous "love test" in King Lear, the Bible story of Lot’s wife turning to a pillar of salt, and many folk traditions illustrate the importance of salt in human culture and history. FAMOUS EXAMPLES According to the Giant Crystal Project, the largest halite crystal is 3 feet by 3 feet (1.1 m by 1.1 m). It was found at Merkers potash mine in Thuringia, Germany. Crystals of similar size have been reportedly found at Carlsbad, New Mexico, in the United States. SUBSTITUTES/SYNTHETICS Salt is widespread and inexpensive, so replacing it with other substances is not common. However, calcium chloride and potassium chloride, other salts, are sometimes used to de-ice roads.	Halite Sample Rock Encrusted with Halite Crystals Halite Crystals and Peppercorns Salt Crystals HALITE FACTS Group: Halide Chemical Formula: NaCl Crystal Structure: Isometric Hardness (Mohs): 2½ Color: Colorless or white; also blue, purple, red, pink, yellow, orange, or gray Transparency: Transparent Luster: Vitreous Density: 2.17 Streak: White Cleavage: Perfect {001}, three directions cubic Fracture: Conchoidal Tenacity: Brittle
	Some data courtesy of the Mineralogical Society of America Author: World Trade Press