Magnesium sulfide is an inorganic compound with the formula Mg S. It is a white

crystalline A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

material but often is encountered in an impure form that is brown and non-crystalline powder. It is generated industrially in the production of metallic iron.

Preparation and general properties

MgS is formed by the reaction of sulfur or hydrogen sulfide with

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

. It crystallizes in the rock salt structure as its most stable phase, its

zinc blende Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Va ...

and

wurtzite Wurtzite is a zinc and iron sulfide mineral with the chemical formula , a less frequently encountered structural polymorph form of sphalerite. The iron content is variable up to eight percent.Palache, Charles, Harry Berman & Clifford Frondel (19 ...

structures can be prepared by

molecular beam epitaxy Molecular-beam epitaxy (MBE) is an epitaxy method for thin-film deposition of single crystals. MBE is widely used in the manufacture of semiconductor devices, including transistors, and it is considered one of the fundamental tools for the devel ...

. The chemical properties of MgS resemble those of related ionic sulfides such as those of sodium, barium, or calcium. It reacts with oxygen to form the corresponding sulfate,

magnesium sulfate Magnesium sulfate or magnesium sulphate (in English-speaking countries other than the US) is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, ...

. MgS reacts with water to give hydrogen sulfide and

magnesium hydroxide Magnesium hydroxide is the inorganic compound with the chemical formula Mg(OH)2. It occurs in nature as the mineral brucite. It is a white solid with low solubility in water (). Magnesium hydroxide is a common component of antacids, such as milk ...

Applications

In the

BOS ''Bos'' (from Latin '' bōs'': cow, ox, bull) is the genus of wild and domestic cattle. ''Bos'' is often divided into four subgenera: ''Bos'', ''Bibos'', ''Novibos'', and ''Poephagus'', but including these last three divisions within the gen ...

steelmaking Steelmaking is the process of producing steel from iron ore and carbon/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon (the most important impurity) are removed from the sourced iron, and alloy ...

process, sulfur is the first element to be removed. Sulfur is removed from the impure blast furnace iron by the addition of several hundred kilograms of magnesium powder by a lance. Magnesium sulfide is formed, which then floats on the molten iron and is removed. MgS is a wide band-gap direct

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

of interest as a blue-green emitter, a property that has been known since the early 1900s. The wide-band gap property also allows the use of MgS as photo-detector for short wavelength ultraviolet light.

Occurrence

Aside from being a component of some slags, MgS is a rare nonterrestrial

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

niningerite Niningerite is a magnesium-iron-manganese sulfide mineral with the chemical formula MgS that is found in enstatite chondrite meteorites. Niningerite is the magnesium-dominant analog of keilite. This mineral is named after Harvey H. Nininger. ...

detected in some meteorites. MgS is also found in the circumstellar envelopes of certain evolved carbon stars, i. e., those with ''C/O'' > 1.

Safety

MgS evolves hydrogen sulfide upon contact with moisture.

References

{{Sulfides Sulfides Magnesium compounds II-VI semiconductors Rock salt crystal structure