What is the main ingredient in face powder?

Talc or talcum is a clay mineral composed of hydrated magnesium silicate with the chemical formula H2Mg3(SiO3)4 is the main ingredient in face powders that absorbs moisture and oil.

It is also called as French Chalk. Other ingredients include Calcium carbonate (chalk), Magnesium carbonate, China clay, starches like rice and potato, zinc oxide,...