Talc, Hydrous magnesium silicate Mg3Si4O10(OH)2 is a hydrous magnesium silicate mineral with a chemical composition of Mg3Si4O10(OH)2. Although the composition of talc usually stays close to this generalized formula, some substitution occurs. Talc, a mineral made up mainly of the elements magnesium, silicon, and oxygen. As a powder, it absorbs moisture well and helps cut down on friction, making it useful for keeping skin dry and helping to prevent rashes.
