Soapstone Rock | Properties, Composition, Formation, Uses
It may be schistose or massive. Soapstone is formed by metamorphism of ultramafic protoliths (eg dunite or serpentinite) and metasomatism of siliceous dolomites. By mass, "pure" steatite is roughly 63.37% silica, 31.88% magnesia, and 4.74% water. It commonly contains minor quantities of other oxides such as CaO or Al2O3. Soapstone …