Silt Silt Silt is granular material of a size between sand and clay, whose mineral origin is quartz and feldspar. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water (also known as a suspended load) and soil in a body of water such as a river. It may also exist as soil deposited at the bottom of a water body, like mudflows from landslides. Silt has a moderate specific area with a typically non-sticky, plastic feel. Silt usually has a floury feel when dry, and a slippery feel when wet.
Soil mechanics may be given the classification symbol "GW" (well-graded gravel), "GP" (poorly graded gravel), "GM" (gravel with a large amount of silt), or "GC" (gravel with a large amount of clay). Likewise sands may be classified as being "SW", "SP", "SM" or "SC". Sands and gravels with a small but non-negligible amount of fines (5–12%) may be given a dual classification such as "SW-SC". Clays and Silts, often called 'fine-grained soils', are classified according to their Atterberg limits; the most commonly used Atterberg limits are the Liquid Limit (denoted by "LL" or formula_39), Plastic Limit (denoted by "PL" or formula_40), and