Talcum powder is a fine powder obtained by mechanically crushing talc ore after removing impurities. Processed and purified talcum powder exhibits a high negative ion generation rate and a high far-infrared emission rate. Talc is also known as tourmaline. The chemical formula of tourmaline is NaR3Al6Si6O18BO33(OH,F)4, which is a general term for a group of cyclic silicate minerals in the trigonal crystal system. In this formula, R represents a metal cation; when R is Fe2+, it forms a black crystal tourmaline. Tourmaline crystals are nearly triangular in columnar shape, with different crystal forms at both ends, a columnar surface with longitudinal streaks, and often occur in columnar, needle-like, radiating, and massive aggregates. They have a glassy luster, with a resinous luster on the fracture, and are semitransparent to transparent. They lack cleavage. The Mohs hardness is 7-7.5, and the specific gravity is 2.98-3.20. They possess piezoelectric and pyroelectric properties.