The chemical properties of MgS resemble those of related ionic sulfides such as those of sodium, barium, or calcium.

Sulfur is removed from the impure blast furnace iron by the addition of several hundred kilograms of magnesium powder by a lance.

[4] MgS is a wide band-gap direct semiconductor of interest as a blue-green emitter, a property that has been known since the early 1900s.

[5] The wide-band gap property also allows the use of MgS as photo-detector for short wavelength ultraviolet light.

[6] Aside from being a component of some slags, MgS is a rare nonterrestrial mineral niningerite detected in some meteorites.