Chemical Composition
sand, mineral, rock, or soil particles that range in diameter from 0.02 to 2 mm (0.0008–0.08 inch). Most of the rock-forming minerals that occur on the Earth’s surface are found in sand, but only a limited number are common in this form, Although in some localities feldspar, calcareous material, iron ores, and volcanic glass are dominant constituents of sand, quartz is by far the commonest, for several reasons: it is abundant in rocks, is comparatively hard, has practically no cleavage so that it is not readily worn down, is nearly insoluble in water, and does not decompose., . Most quartzose sands contain a small quantity of feldspar, as well as small plates of white mica, which, though soft, decompose slowly.