Polishing materials are substances used to smooth and shine surfaces. EMERY, SAND, and pumice are all commonly used for polishing. EMERY is a hard, granular material made of corundum, magnetite, and other minerals. SAND is a loose, granular material composed of small particles of rock and mineral. Pumice is a light, porous volcanic rock that is often used as an abrasive. All three materials can be used to polish surfaces and create a smooth, shiny finish.