The particles that make up soil are categorized into three groups by size – sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Most soils are a combination of the three. The relative percentages of sand, silt, and clay are what give soil its texture. A clay loam texture soil, for example, has nearly equal parts of sand, slit, and clay.
Sand – 2.0 to 0.05 mm
Silt – 0.05 to 0.002 mm
Clay – less than 0.002 mm