Talc and Soapstone

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 and soapstones roll crushers, ring-roller, pebble, and jet mills... 

Hopkins (1914) Hopkins, O.B.,4 Report on the Asbestos, Talc and Soapstone Deposits of Georgia. Geological Survey of Georgia, Bulletin No. 29 (1914)... 

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. 

Toxicology. The fibrous talc in soapstone dust causes fibrotic pneumoconiosis an increased incidence of cancer of the lungs and pleura has been reported. 

Soapstone is produced by alteration of serpentine in several possible ways. In some cases, the serpentine is directly replaced by carbonate (magnesite) and talc leaving a rock consisting chiefly of talc and magnesite with some minor magnetite. 

Two important factors are suggested by this model. First, the concentration of a trace element in a particular mineral (like talc) formed in this manner depends upon many factors including the size and charge of the ion (which eflFect the partition coefficient), the composition of the aqueous solution, the minerals present in the intrusive (determines D ), and the time or extent of reaction. Since talcose rocks of similar composition can be formed by various different processes, the differences in any of the factors noted above would result in different trace element contents. Second, since the assumption that the partition coefficients for antigorite, talc, and tremolite are similar appears to be true, one would expect their trace element contents to be similar. This means that a series of soapstone samples collected from a particular geologic body might contain different amounts of these minerals but that they all would probably be very similar in trace element content despite differences in the bulk element composition of the samples. 

Occurs as carbonate in dolomite or magnesias limestone, and as silicate in mica, asbestos, soapstone, meerschaum, talc, and in other minerals. It also accompanies Ca in the forms in which it is found in the animal and vege table worlda... 

The bronze age did not arrive in China until around 1500 bce, and iron appeared only about 500 bce, but by the beginning of their alchemical age, around 100 ce, the Chinese had knowledge of zinc and brass (a copper-zinc alloy), mercury, sulfur, and several of the common salts, such as niter. In the 400s bce an administrator made a list of known materials that included lead oxide, lead carbonate, sulfur, calcium carbonate, hydrated calcium sulfate, ferric oxide, niter, talc or soapstone, hydrated magnesium silicate, alum (the double sul-... 

Acceptable dusting agents soapstone, talc and Crystal 2000. 

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. 

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. 

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