Activated charcoal is a specially processed form of carbon. It is used in natural soaps for its cleansing qualities and high adsorptive powers.
When charcoal is activated, it causes the carbon to form pockets in its surface. Impurities like dirt and oil get trapped in these carbons pores, and drawn away from the skin.
Through this process, charcoal cleanses and treats skin, helping to relieve acne and other skin problems.