Soapstone
（重定向自Steatite）
Soapstone (also known as steatite, or soaprock) is a talc-schist., which is a type of metamorphic rock. It is largely composed of the mineral talc and is thus rich in magnesium. It is produced by dynamothermal metamorphism and metasomatism, which occurs in the zones 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.