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Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula Mg 3 Si 4 O 10 (OH) 2. Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material.
Talc is much softer and feels soapy between the fingers. [4] [5] The typical general formula for chlorite is (Mg,Fe) 3 (Si,Al) 4 O 10 (OH) 2 ·(Mg,Fe) 3 (OH) 6. This formula emphasizes the structure of the group, which is described as TOT-O and consists of alternating TOT layers and O layers. [3]
The Mohs Hardness Scale is the main scale to measure mineral hardness. Finger nail is 2.5, copper coin is 3.5, glass is 5.5 and steel is 6.5. Hardness scale is Talc is 1, Gypsum is 2, Calcite is 3, Fluorite is 4, Apatite is 5, Orthoclase Feldspar is 6, Quartz is 7, Topaz is 8, Corundum is 9 and Diamond is 10. Odor; Not always recommended.
The 2:1 clay minerals (pyrophyllite-talc) consist of T-O-T stacks, but they are softer (hardness from 1 to 2), as they are instead held together by van der Waals forces. These two groups of minerals are subgrouped by octahedral occupation; specifically, kaolinite and pyrophyllite are dioctahedral whereas serpentine and talc trioctahedral. [114]
Magnetic mineralogy is the study of the magnetic properties of minerals. The contribution of a mineral to the total magnetism of a rock depends strongly on the type of magnetic order or disorder. Magnetically disordered minerals (diamagnets and paramagnets) contribute a weak magnetism and have no remanence.
Manufacturers of baby powder and cosmetic products made with talc will have to test them for asbestos under a proposal announced by the U.S. Food and Drug Administration. The agency's proposal ...
(Reuters) -Johnson & Johnson must pay $15 million to a Connecticut man who alleges that he developed mesothelioma, a rare form of cancer, as a result of using the company's talc powder for decades ...
Nelsonite is an igneous rock primarily constituted of ilmenite and apatite, with anatase, chlorite, phosphosiderite, talc and/or wavellite appearing as minor components. Rocks are equigranular with a grain size around 2 – 3 mm. [2] The black ilmenite is slightly magnetic while the whitish apatite is not. [3]