Natural Volcanic Pumice. Enjoy a safe natural way to treat and care for your feet, free from harmful toxins found in other synthetic foot stone pumice. Our unique natural and mineral rich lava stones keep your feet feeling soft and smooth! Perfect for pedicures, feel your feet come back to life, naturally exfoliating pumice stone helps remove dead skin. Make every day a spa experience. Circle the foot and heel with the callus remover to file and remove excess skin, calluses and corns from your feet. Color and shape may vary slightly as this is a natural product and each of them has its own unique shape.