Hydrated magnesium silicate

A hydrated magnesium silicate in fibrous form. The fibres are believed to be the more hazardous component of asbestos dust. 

The stabilizing effects of methylcellulose and hydrated magnesium silicate were applied to calamine lotion. Sample 1 was the U.S.P. XV calamine lotion, and sample 2 the U.S.P. XV calamine lotion with 0.5% of methylcellulose. Sample 1 showed 50% separation, while sample 2 showed 12% separation after 24 hours at room temperature. 

Sepiolite, also known as meerschaum or sea foam, is a white or off-white soft clay of low density. It is composed of hydrated magnesium silicate and occurs in consolidated masses that are easily carved and whose surfaces can be smoothed and endowed with a durable polish. It is for this reason that meerschaum has been used, since antiquity, for making ornaments and decorative carvings. For many centuries meerschaum has been intensively mined in Greece and Turkey. 

Talc is a hydrated magnesium silicate, Mg6(Si802o)(OH)4. It is a layerd compound like mica. One layer of its crystal structure is shown schematically in Figure 11.3. Such layers are stacked up like playing cards in real crystals. Notice that the top and bottom of the layer consist of slicate tetrahedra with oxygen... 

A hydrated magnesium silicate in the form of a soft white powder. It is used as a dusting agent,... 

Chrysotile A mineral in the serpentine group composed of hydrated magnesium silicate, which occurs in several crystalline modifications (see chapter 2) and usually in fibrous form. First described and named in 1834, chrysotile fibers were mined under the name serpentine-asbestos, or simply asbestos, long before that time. 

Gay is used as a filler in compounding paper and rubber. Talc, a naturally occurring fibrouslike hydrated magnesium silicate, is used to improve the thermal resistance of polypropylene (PP). Since talc-filled PP is much more resistant to heat than unfilled PP, it is used in automotive accessories subject to high temperatures. Over 40 million tons of talc are used annually as a filler. 

Fe, Fe and Al are found in magnesian talc and it also has a ferrous form minnesotaite. However, the talc found in sedimentary rocks in sediments is predominantly hydrated magnesium-silicate. 

Soapstone - A soft powder or stone, basically hydrated magnesium silicate, having a soapy feel, used to dust the surface of un-vulcanized rubber compounds to keep them from sticking together. Similar to talc. 

Canada Asbestos. An impure chrysolite, a hydrated magnesium silicate 3MgO, 2Si2H2,2H20 Ref Hackh s (1944), 162 201... 

Talc is a hydrated magnesium silicate that is composed of thin platelets primarily white in color. Talc is useful for lowering the cost of the formulation with minimal effect on physical properties. Because of its platy structure and aspect ratio, these extenders are considered reinforcement. Polymers filled with platy talc exhibit higher stiffness, tensile strength, and creep resistance, at ambient as well as elevated temperatures, than do polymers filled with particulate fillers. Talc is inert to most chemical reagents and acids. The actual chemical composition for commercial talc varies and is highly dependent on the location of its mining site. 

Talc or hydrated magnesium silicate is another mineral that is used to reinforce epoxy adhesives. It has a platelike structure that provides good stiffness and creep resistance at elevated temperatures. It also provides good electrical and chemical resistance characteristics.26 It is relatively inexpensive and disperses well in the resin. 

Under some circumstances, the Mg enters sparingly soluble phases other than brucite. Roy et al. (R70) observed the formation of a hydro-talcite-type phase in a slag cement paste that had been treated with MgS04 solution. Its formation was possibly favoured by the enhanced availability of A1(0H)4 provided by the slag. Cole (C70) reported the formation of a hydrated magnesium silicate in a deteriorated concrete seawall. 

SAFETY PROFILE Soluble alkaline siUcates act locally like mild alkalies. The dusts of certain silicates, such as asbestos (hydrated magnesium silicate) and talc, can produce... 

Natural hydrated magnesium silicate Talc 14807-96-6 Mg3Si40io(OH)2 (Pure talc)... 

Hydrate magnesium silicate Silicic acid, magnesium salt, hydrate 1343-90-4 Unspecified... 

Hydrated magnesium silicate (Talc, 3Mg0 4Si02 H20, CAS No. 14807-96-6) is a magnesium silicate commonly referred to as "soapstone". It is obtained from natural sources and may contain a small amount of aluminum silicate. It is composed of MgO (31.7%), Si02 (63.5%), and H2O (4.8%). It is a crystalline nonhygroscopic, odorless, tasteless powder which is practically insoluble in water, dilute mineral acids, dilute solutions of alkali halides, and alkaline hydroxides but is soluble in hot concentrated sulfuric acid. 

Talcs (RI 1.55) are hydrated magnesium silicates. It is extremely soft and is characterized by its slippery feel. Talc is used in paint to assist the dispersion of titanium dioxide and to improve the application properties of the paint film. 

Talc is a purified, hydrated, magnesium silicate, approximating to the formula Mgg(Si205)4(0H)4. It may contain small, variable amounts of aluminum silicate and iron. 

The most significant representative, talc, is hydrated magnesium silicate having the formula Mg3(Si205)2 (OH)2, i.e. molecular composition 3 MgO. 4 Si02. H2O, It has a layer structure similar to that of clay minerals, which is the cause of ready cleavability and of the macroscopically laminar character of some varieties. Its density lies in the range 2.6 —2.8 g/cm. The talc structure does not provide conditions for major substitution by other elements. 

Chrysotile is a hydrated magnesium silicate and its stoichiometric chemical composition may be given as AIg3SyOs(OH)4 [12001 -29-5]. However, the geothermal processes which yield the chrysotile fiber formations usually involve the co-deposition of various other minerals. These mineral... 

Talc is hydrated magnesium silicate, a nonmetallic mineral, white-colored, chemically inert. Unlike many other minerals, its particles have a distinct platy shape. It has a natural affinity to oil and, therefore, serves as a good filler for hydrophobic plastics, such as polyethylenes and polypropylene. Platy particles of talc are structurally not uniform they have a layered composition, in which a brucite (magnesium-based, tetrahedron-cell atomic structure) sheet is sandwiched between two silica (octahedron-cell atomic structure) sheets. The elementary sheet is of ik (0.7 nm) thick. 

Effect of Moisture on the Chromatographic Properties of a Synthetic Hydrated Magnesium Silicate, M. L. Wolfrom, Alva Thompson, T. T. Galkowski, and E. J. Quinn, Anal. Chem., 24, 1670-1671 (1952). 

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