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Construction Safety and Health
Outreach Program		 U.S. Department of Labor
OSHA Office of Training and Education
May 1996

Field Method for Identification of Soil Texture
 
Soil Texture Visual Detection of Particle Size and General Appearance of the Soil Squeezed in hand and pressure released Soil ribboned between thumb and finger when moist
When air dry When Moist
Sand Soil has a granular appearance in which the individual grain sizes can be detected. It is free-flowing when in a dry condition. Will not form a cast and will fall apart when pressure is released. Forms a cast which will crumble when lightly touched. Can not be ribboned.
Sandy Loam Essentially a granular soil with sufficient silt and clay to make it somewhat coherent. Sand characteristics predominate. Forms a cast which readily falls apart when lightly touched. Forms a cast which will bear careful handling without breaking. Can not be ribboned.
Loam A uniform mixture of sand, silt and clay. Grading of sand fraction quite uniform from coarse to fine. It is mellow, has somewhat gritty feel, yet is fairly smooth and slightly plastic. Forms a cast which will bear careful handling without breaking. Forms a cast which can be handled freely without breaking. Can not be ribboned.
Silt Loam Contains a moderate amount of the finer grades of sand and only a small amount of clay. Over half of the particles are silt. When dry it may appear quite cloddy which readily can be broken and pulverized to a powder. Forms a cast which can be freely handled. Pulverized it has a soft flourlike feel. Forms a cast which can be freely handled. When wet, soil runs together and puddles. It will not ribbon but it has a broken appearance, feels smooth and may be slightly plastic.
Silt Contains over 80% of silt particles with very little fine sand and clay. When dry, it may be cloddy, readily pulverizes to powder with a soft flourlike feel. Forms a cast which can be handled without breaking. Forms a cast which can freely be handled. When wet, it readily puddles. It has a tendency to ribbon with a broken appearance, feels smooth.
Clay Loam Fine textured soil breaks into very hard lumps when dry. Contains more clay than silt loam. Resembles clay in a dry condition; identification is made on physical behavior of moist soil. Forms a cast which can be freely handled without breaking. Forms a cast which can be handled freely without breaking. It can be worked into a dense mass. Forms a thin ribbon which readily breaks, barely sustaining its own weight.
Clay Fine textured soil breaks into very hard lumps when dry. Difficult to pulverize into a soft flourlike powder when dry. Identification based on cohesive properties of the moist soil. Forms a cast which can be freely handled without breaking. Forms a cast which can be handled freely without breaking. Forms long, thin flexible ribbons. Can be worked into a dense, compact mass. Considerable plasticity.
Organic Soils Identification based on the high organic content. Muck consists of thoroughly decomposed organic material with considerable amount of mineral soil finely divided with some fibrous remains. When considerable fibrous material is present, it may be classified as peat. The plant remains or sometimes the woody structure can easily be recognized. Soil color ranges from brown to black. They occur in lowlands, in swamps or swales. They have high shrinkage upon drying.