Kaku Mineral and Chemical Industries
More Details about the Soapstone / Talc powder. Soapstone / Talc powder Talc is a mineral composed of hydrated magnesium silicate with the chemical formula H2Mg3(SiO3)4 or Mg3Si4O10(OH)2. It is the softest known mineral and listed as 1 on the Mohs hardness scale. it has a distinctly greasy feel.