Soapstone is a talc-schist, which is a
type of metamorphic rock.
It is composed largely of the magnesium rich
mineral talc.
It is produced by dynamothermal metamorphism and
metasomatism, which occur 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.