Talc is a clay mineral made up of hydrated magnesium silicate and oxygen mined from the rock deposits in the earth. Manufacturers crush, dry and mill talc into a fine, soft white powder called talcum powder. As a powder, talc easily absorbs moisture, prevents caking, and aids in keeping skin dry in order to prevent rashes. The talcum powder adds softness and shine to products, which makes it a common ingredient in cosmetics. Talc is also used as a thickening agent and lubricant, and is also an ingredient in many industrial products including paint and joint compound (mud).
Some talc, in its natural form, contains asbestos, which is a known carcinogen. Exposure to asbestos may cause mesothelioma or lung cancer. Many talc deposits are contaminated with asbestos due to their proximity to tremolite mines. Tremolite is a type of asbestos.