Abrasive exfoliants include gels, creams or lotions, as well as physical objects. Loofahs, microfiber cloths, natural sponges, or brushes may be used to exfoliate skin, simply by rubbing them over the face in a circular motion. Gels, creams, or lotions may contain an acid to encourage dead skin cells to loosen, and an abrasive such as microbeads, sea salt and sugar, ground nut shells, rice bran, or ground apricot kernels to scrub the dead cells off the skin. Salt and sugar scrubs tend to be the harshest, while scrubs containing beads or rice bran are typically very gentle.