Talc

Talc is the major component of most powder makeup products (think face powder, eyeshadows, and blushers) that usually contain it up to 70%. Its two winning properties that make it very suitable for this role is its outstanding spreadability for a smooth application and its low covering power, aka translucency to avoid clown-like effects.

Chemically speaking, it is a clay mineral(hydrated magnesium silicate) that is mined in several countries. The drawback of mined minerals is potential impurities and the version used in cosmetics has to be white (not gray like cheaper grades), free from asbestos, sterilized and have thin plates for a maximum slip.