Soapstone

Talc. Talc (qv) [14807-96-6] (Cl Pigment White 26, Cl No. 77019), is finely powdered, native, hydrous magnesium sihcate, 3MgO 4Si02 H20 (soapstone) sometimes containing a small amount of aluminum siUcate. It is produced ia many parts of the world, including France, Italy, India, and the United States. 

Soft Materials (1) Talc, dried filter-press cakes, soapstone, waxes, aggregated salt ciystals (2) gypsum, rock salt, ciystahine salts in gener, soft coal (3) calcite, marble, soft limestone, barites, chalk, brimstone. 

Talc and Soapstone Generally these are easily pulverized. Certain fibrous and foliated talcs may offer greater resistance to reduc tion to impalpable powder, but these are no longer produced because of their asbestos content. 

Talc, unlike Che micas, consists of electrically neutral layers without the interleaving cations. It is valued for its softness, smoothrtess and dry lubricating properties, and for its whitertess, chermcal inertness and foliated structure. Its most important abdications are in ceramics, insecticides, paints and paper manufacture. The more familiar use in cosmetics and toilet preparations accounts for only 3% of world production which is about 5 Mt per annum. Half of this comes from Japan and the USA. and other major producers are Korea, the former Soviet Union, France and China. Talc and its more massive mineral form soapstone or steatite arc widely distributed throughout the world and many countries produce it for domestic consumption either by open-cast or underground mining. 

Talk-pulver, n. talcum powder, -schiefer, m. talc schist, talcose slate, slaty talc. >spat, m. magnesite, -stein, m. soapstone, steatite. Talkum, n. talc, talcum. 

Soapstone Respirable dust Total dust Sodium azide Sodium bisulphite —... 

A number of nonmetallic mineral deposits are formed during metamorphism as a result of recrystallisation. Important among these are graphite, asbestos, talc, soapstone and pyrophyllite, kyanite, sillimanite, and semi precious stones like garnet and emery. 

Soapstone Carving decorative objects Complex silicate of magnesium Greasy feel easily carved... 

Luckenback, A. H., C. G. Holland, and R. O. Allen (1975), Soapstone artifacts Tracing prehistoric trade patterns in Virginia, Science 187, 57-58. 

A bar of talc feels like a bar of soap which is why it is often called soapstone. Its exceptional softness (it is the softest of the Mohs minerals) is a direct result of its unusual crystal structure. This consists of sheets of silicate tetrahedra without metal ions between the sheets. Thus the sheets are bonded only by London polarization forces. The latter are particularly weak because silicate tetrahedra have relatively small polarizabilities. 

Any substance used to prevent rubber sticking to itself or to the surface of a mould. The lubricant may be a dry powder such as soapstone or a liquid such as silicone emulsion. See Dusting Agent and Mould Release Agent. 

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