Sidewalk material is a term used to describe the materials used to construct sidewalks. The most common materials used are STONE, CONCRETE, and CEMENT. STONE is a natural material composed of rock or mineral fragments, usually found in the ground. CONCRETE is a man-made material made from a mixture of CEMENT, sand, gravel, and water. CEMENT is a powdery substance made from a combination of limestone, clay, and other materials that is mixed with water to form a paste.