A sand particle is a small granular material composed of finely divided rock and mineral particles. It is the smallest unit of a sedimentary rock, typically measuring between 0.0625 and 2 millimeters in diameter. Sand particles are found in deserts, beaches, riverbeds, and other areas where wind and water have eroded rocks and minerals. The term 'GRAIN' is often used to refer to a sand particle, as it is a small, granular material.