manganese monoxide

Manganese monoxide, also known as manganous oxide or manganese(II) oxide (MnO), is an insoluble compound of manganese. It is found in nature as the mineral manganosite and can be produced by heating other manganese oxides with hydrogen. This green powder is easily oxidized.1

Manganese monoxide serves as a starting material for producing manganous salts and is used as an additive in fertilizers and as a reagent in textile printing. It can be prepared by heating manganese carbonate without air or by passing hydrogen or carbon monoxide over manganese dioxide. Manganese itself is a chemical element, a silvery-white, hard, and brittle metal that is crucial for steelmaking.2