Sand

Sand, in geology, collection of rock particles with diameters in the range 0.125–2.0 mm. It can be graded according to particle size: fine, medium, coarse, and very coarse. Sands result from erosion by glaciers, winds, or ocean or other moving water. Their chief constituents are usually quartz and feldspar. Sand's uses include making bricks, cement, glass, and concrete.