Steatite,

Steatite, or SOAPSTONE, a compact or massive variety of Talc (q.v.), is a hydrous silicate of magnesia. It is found massive, or sometimes assuming the forms of the crystals of other minerals which it has replaced. It is plentiful in many parts of the world, and is found in various parts of Britain. It is generally white, reddish white, or yellow. It is soft and greasy to the touch, easily cut, but broken with difficulty. It is used in the manufacture of porcelain. It writes readily on glass, and is used by glaziers for marking plates of glass before they are cut with the diamond. Tailors use it for marking cloth before they cut it. It is also used by shoemakers to give unctuousness to the heels of stockings that new boots may more easily be tried on. It is sold for such purposes under the names of Briançon Chalk, French Chalk, and Venice Talc. It readily absorbs oil or grease, and is used in powder for extracting spots of them from silken and woollen stuffs. It is the basis of Rouge (q.v.). It is used for imitating engraved stones, being easily cut, and afterwards hardened by heat; after which it may be coloured by metallic solutions. It also forms a polishing material for serpentine, alabaster, and glass. The so-called Agalmatolite or Pagodite of China, which is carved into images, miniature pagodas, &c., is usually not steatite but a variety of the mineral called Pinite. In other cases it is a compact variety of Pyrophyllite. Now and again it is steatite.