A pumice stone is a lightweight, porous volcanic rock that is used as an exfoliating tool to remove dead skin cells and smooth rough areas, particularly on the feet, elbows, and knees. When gently rubbed on dampened skin, the abrasive texture of the pumice stone helps to slough off dry and hardened skin, revealing softer and smoother skin underneath. It is a popular tool for achieving smoother feet and promoting overall skin health, providing an effective and convenient solution for personal care routines.