Sand is a mixture of very small pieces of different rocks or minerals. It is the same minerals from which those pieces are broken, such as granite and feldspar. Sand is gritty to touch. It is a naturally occurring granular material composed of finely divided rock and mineral particles. Sand is also formed from various rocks by weathering and erosion. Erosion breaks large boulders into smaller rocks. They get smaller and smaller until they reach the beach or a low-lying area as sand.