Soapstone (also known as steatite or soaprock) is a metamorphic
rock, a talc-schist. It is largely composed of the mineral talc and is rich in
magnesium. It is produced by dynamothermal metamorphism and metasomatism, which
occurs in the areas where tectonic plates are subducted, changing rocks by heat
and pressure, with influx of fluids, but without melting. It has been a medium
for carving for thousands of years.