soapstone

soapstone or steatite , metamorphic rock of which the characteristic and usually chief mineral is talc , but which also contains varying parts of chlorite, mica, tremolite, quartz, magnetite, and iron compounds. It is gray to green in color, has a soapy feel, and is notable for its high degree of resistance to acids and heat. It is so soft that it can be easily cut with a knife or other sharp tool, making it a popular material for sculpting. The chief deposits of commercial importance are in the United States, Norway, and Canada. It is used in the manufacture of laboratory table tops, kitchen sinks, laundry tubs, furnace linings, and electrical apparatus.

soap·stone / ˈsōpˌstōn/ • n. a soft rock consisting largely of talc. Compare with steatite.

soapstone (also called steatite). A very soft smooth stone (composed of magnesium silicate), superficially like marble or jade in appearance but with a greasy, soapy feel. It is a compact form of talc, the softest standard mineral on the Mohs scale of hardness. Usually it is a dull greenish or bluish grey or sometimes brown. It will take a smooth polish, and is so easily worked that it may even be carved with a knife. Because of this quality it has been used in many parts of the world, from ancient times onwards, mainly for fairly small objects and utensils, but also for large sculpture, for example by António Francisco Lisboa in colonial Brazil.