Calcium Carbonate is found in chalk, limestone, marble and travertine. Even eggshells are 95% calcium carbonate!
Calcium Carbonate has a gazillion uses that are not related to cosmetics. It is a filler in plastics, in paint, a whitening agent in ceramics, in toothpaste, to make chalk, it is used as a dietary supplment . . . and on and on.
Calcium Carbonate absorbs moisture. So, it is often added to face powders to increase the ability of the makeup to absorb moisture.
In cosmetics, Calcium Carbonate makes a great absorber in foundations, primers and finishing powders. Use in a percentage of about 2-5% of the formula to start.
This is a cosmetic additive.
Approved for use on:lips, eyes, face, nails.