Different soil minerals and their diameter range in mm as Classified by U.S.D.A.:
- Stones: > 76 mm
- Gravel: 76.0 mm-2.0 mm
- Very Coarse Sand: 2.0 mm-1.0 mm
- Coarse Sand: 1.0 mm-0.5 mm
- Medium Sand: 0.5 mm-0.25 mm
- Fine Sand: 0.25 mm-0.10 mm
- Very Fine Sand: 0.10 mm-0.05 mm
- Silt: 0.05 mm-0.002 mm
- Clay: <0.002 mm