Brucite Wikipedia
Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg() is a common alteration product of periclase in marble; a lowtemperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of is often found in association with serpentine, calcite, aragonite, dolomite, magnesite, hydromagnesite ...