Sand Sand Sand is a granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO), usually in the form of quartz. The second most common type of sand is
Granular material the partitions rather than spread evenly into both partitions as would happen in a conventional gas. This effect, known as the granular Maxwell's demon, does not violate any thermodynamics principles since energy is constantly being lost from the system in the process. Granular systems are known to exhibit jamming and undergo a jamming transition which is thought of as a thermodynamic phase transition to a jammed state. The Lubachevsky-Stillinger algorithm of jamming allows one to produce simulated jammed granular configurations. Excited granular matter is a rich pattern-forming system. Some of the pattern-forming behaviours seen in granular materials are: Some of