Material consisting of fragmented particles of mostly siliceous rock, specifically as it appears on the surface of a beach or a desert. Individual particles may range in diameter from approximately 0.0008-0.08 inch. Most rock-forming minerals at the Earth's surface may be constituents of sand, but a limited number are common. Quartz is most common.

http://vocab.getty.edu/page/aat/300014341
 Source: AAT