Talc
Talc is a naturally occurring hydrated magnesium silicate mineral with the ideal chemical formula Mg3Si4O10(OH)2. It is the softest known mineral, ranking 1 on the Mohs scale, and is notable for its greasy or soapy feel. Talc’s chemical inertness, softness, and ability to absorb moisture make it valuable in a wide range of industrial and consumer applications.