In soil science, a coating is a layer of material, such as clay, organic material, mineral, non-crystalline material, etc., that partially or completely covers soil components (e.g., grains, voids). The term excludes b-fabrics.
Syn., cutan;
Cf., hypo-coating

Cohesion refers to the attractive forces (e.g., van der Waals, Coulombic) between two molecules of the same kind or two surfaces of similar material. For example, the shear strength of wet clayey soils involves both cohesive forces and friction. For wet clayey soils, the cohesion component of shear strength primarily results from the surface interactions between two clay particles (of similar composition and structure).
Cf., adhesion

An entity, either a solid or a liquid, dispersed in a medium. The entity must have one of its dimensions between 1 nm and 1 μm. A colloid dispersed in a liquid is also termed a “sol”. The term may be used also for the system as a whole. (after Lyklema 1991).
See gelling clay.

See suspension.

See suspension.

An obsolete term for roscoelite.

The relationship where a superstructure (or superlattice) is equal to an integral number of subcells (or sublattices). For example, some crystals of antigorite exist where the substructure a-cell dimension is 5.4 Å, and the superstructure of 32.4 Å, occurs from a wave-like curvature of the 1:1 along the [100] direction. Because the superstructure is 6 x 5.4 Å = 32.4 Å, the superstructure is commensurate with the substructure. In other crystals of antigorite, the superstructure may be related to the substructure by a non-integer number of subcells, and this is referred to as a non-commensurate relationship.

The relationship where a superstructure (or superlattice) is equal to an integral number of subcells (or sublattices). For example, some crystals of antigorite exist where the substructure a-cell dimension is 5.4 Å, and the superstructure of 32.4 Å (6 x 5.4 Å), occurs from a wave-like curvature of the 1:1 layers along the [100] direction. Because the superstructure is a multiple of the subcell dimension, the superstructure is commensurate with the substructure. In other crystals of antigorite, the superstructure may be related to the substructure by a non-integer number of subcells, and this is referred to as an incommensurate or non-commensurate relationship.

An obsolete term for muscovite.

See cryptocrystalline.