Bentonite Clay (Sodium Bentonite) is a combination of montmorillonite and volcanic ash. Bentonite Clay is a highly absorbent cosmetic clay that pulls oils and toxins from the skin and is one of the best clays for making clay poultices. It is best suited for oily skin. Bentonite Clay is also a good clay for shaving soaps (use about 1 tablespoon per pound of soap) and for use as an oily hair and scalp treatment. Bentonite Clay is suitable for oily skin and hair.