Guide To The Identification
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The texture of sand and finer textured materials can be determined in the field by "feel" (hand texturing). Comparisons of the results from both field examinations and laboratory analysis should be made whenever possible. A number of tests can be done in the field to establish the texture of a sediment, including: (1) moist cast test; (2) ribbon test; (3) feel tests; (4) taste test; and (5) shine test.

Moist Cast Test:

Involves squeezing (compressing) a moist soil sample in your hand. If the soil holds together (i.e., forms a cast), then toss from hand to hand to test strength of cast. The more durable the cast is the more clay present.

Roll moist soil into cigarette-shape between palms of hands, then roll out between thumb and forefinger forming the longest, thinnest ribbon possible.

Includes graininess test, dry feel test, and stickiness test.
Graininess Test: Soil is rubbed between thumb and fingers to assess the percent sand by the grainy feel of the sample.

Dry Feel Test:

Start with moist soil samples with more than 50% sand. Sample is rubbed in the palm of the hand to dry it, and to separate and estimate the size of the individual sand particles. The sand particles will then fall out of the hand and the amount of finer material (silt and clay) remaining can be noted.

Stickiness Test:

Knead a saturated soil sample until the stickiest point is reached. Then compress between the thumb and forefinger. The degree of stickiness is determined by noting how strongly it adheres to the thumb and forefinger upon release of pressure and how much it stretches.

Work a small amount of soil between front teeth. Sand is distinguished as individual grains against the teeth. Silt particles, as a group, have a general fine grittiness, but individual grains cannot be identified. Clay particles have no grittiness (smooth).

A small amount of moderately dry soil is rolled into a ball and rubbed once or twice against a hard, smooth object such as a knife blade or thumb nail. A shine on the ball indicates clay in the soil.

Material made up of sand has a grainy feel and individual sand particles can be readily seen, felt or tasted. Dry sand, when squeezed in the hand, will fall apart when the pressure is released. Moist sand will form a weak cast when squeezed that falls apart when touched.

Material made up of silt feels like flour when pulverized and dry, and has a soapy, non-sticky feel when the sediment is very moist. Silt has a gritty taste when chewed between the teeth. Dry or moist, this material will form a weak cast that can be carefully handled. When moist, silt flakes rather than forming a ribbon.

Material made up of clay has a smooth feel (no graininess) and is plastic and usually very sticky when wet. It has a smooth taste when chewed. Moist sediment will form a very strong cast when pressure is applied, a roll will bear its own weight when flexed and it will form a very thin, long, flexible ribbon (>7.5 cm). It produces a strong shine when rolled into a ball and rubbed once or twice against a hard surface.

Material that is made up of sand, with a lesser amount of silt (20-49%) and that may contain from 0 to 19% clay. There is sufficient finer material (silt and clay) to make it somewhat coherent. Individual sand grains can be seen, felt or tasted. The material feels very grainy with a secondary strong floury feel and may be slightly sticky. If squeezed it will form a weak to moderate cast (depending on the amount of silt/clay present) that will bear careful handling without breaking. No shine is evident. (A silty sand is roughly equivalent to the sandy loam to "light" loam soil textures).

Material that is made up of silt with lesser amount of sand (20-49%) and that may contain from 0 to 19% clay. It has a floury with slight graininess feel and may be slightly sticky when wet. When chewed, it has a silt grittiness with some sand graininess. It forms a weak to moderate cast that allows for careful handling and it flakes rather than forming a coherent ribbon or barely forms a ribbon. No shine is produced. (A sandy silt is roughly equivalent to the silt loam to loam soil texture.)

Material that is made up of sand with a lesser amount of clay (20-49%) and that may contain from 0 to 19% silt. It has a grainy feel (individual sand grains are evident) that is slightly to moderately sticky. The sediment forms a moderate to strong cast; a short (<3 cm), thick to a long (5 to 7.5 cm), thin ribbon that holds its own weight; and the sediment has a slight to moderate shine. (A clayey sand is roughly equivalent to sandy clay loam and sandy clay soil textures).

Material made up of silt with a lesser amount of clay (20-49%) and that may contain from 0 to 19% sand. It has a smooth to smooth with floury feel depending on the amount of silt present and silt grittiness when chewed. The material is sticky to very sticky; forms a strong to very strong cast; produces a slight to moderate shine; and forms fairly thin ribbons barely able to support their own weight, to thin, long (5 to 7.5 cm) ribbons which readily support their own weight. (A clayey silt is roughly equivalent to a silty clay loam to silty clay soil texture).
Sand/Silt/Clay (in any order): Sediments made up of at least 20% sand, 20% silt and 20% clay should display the following characteristics: (1) some to moderate graininess with sand grains evident and should be slightly sticky to sticky when moist, (2) barely forms ribbons to thin ribbons that barely support own weight, (3) forms a moderate to strong cast when clenched, and (4) may produce a slight shine when rolled and rubbed. (A mixture of sand/silt/clay is roughly equivalent to a clay loam to "heavy" loam soil texture.)

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