Talc powder, named PULVISTALCI in English, is white or similar white, fine, non-sandy powder. It feels greasy. It's odorless and tasteless. This product is insoluble in water, dilute mineral acid or dilute alkali hydroxide solution. It can be used as medicine. The main component of talc is magnesium silicate hydrated in talc, and its molecular formula is Mg3 [Si4O10] (OH) 2. Talc belongs to monoclinic system. Crystals are pseudohexagonal or diamond-shaped sheets, occasionally. Usually dense, massive, leafy, radial, fibrous aggregates. It is colorless, transparent or white, but it is light green, light yellow, light brown or even light red due to a small amount of impurities. The cleavage surface is pearly luster. Hardness 1, specific gravity 2.7~2.8.