BRUCITE (from the name of the American mineralogist Archibald Bruce * EN: brucite; DE: Brucit; FR: brucite; ES: brucita; RU: брусит) is the mineral of the class of hydroxides, Mg(OH)2. It contains 69% of MgO, and 31% of H2O. There are possible the admixtures of Fe2+ (ferrobrucite), Mn2+ (manganobrucite), Zn2+. It crystallizes itself into the trigonal crystal system. The structure is layered. It may be found in the form of the continuous foliated masses, or of the fine-fiber aggregates (nemalite). The crystals are tabular, foliated. The colour is white, greenish; the lustre on the plane of cleavage is nacreous, on the fracture is vitreous. The cleavage is perfect along the (001) plane. The hardness is 2.5. The density is 2400 kilograms per cubic metre. It is pyroelectric.

Brucite forms itself during the low-temperature hydrothermal alteration of the magnesial ultrabasic rocks, during the metamorphism of the rocks, and within the crusts of weathering. The main satellites are serpentine, magnesite, hydromagnesite, and chlorite. Within the USSR, the clusters of brucite have been uncovered within the massifs of serpentinites and metamorphosed dolomites of the Urals mountains, Caucasus mountains, and Siberia region. Abroad, there are most known the deposits within the USA, Canada, Italy, and Yugoslavia. It is the promising raw material for the obtainment of magnesium and its compounds.