A set of reference axes used in crystallography. These axes are usually three in number, although in some cases, they may be four. The axes are generally mutually perpendicular, coincide with symmetry axes or the normals to symmetry planes, and in cases where the crystal lacks symmetry, parallel to lines of intersection of two faces with greatest areas. These axes are designated as a, b, c, and angles between axes are designated α, β, and γ where α is located between axes b and c, β is located between axes a and c, etc. according to the right- hand rule.
See also crystal system.

See continuously stirred tank reactor.

See crystal system.

An obsolete name for altered material, probably vermiculite.

See ferromagnetism, ferroelectric.

A pedofeature involving material (commonly oriented clay coatings, but also gels, amorphous, etc. coatings) that covers the surfaces of voids, grains, and aggregates, and are common in paleosols. Cutans may be derived and differentiated as diffusion cutans, illuviation cutans, and stress cutans. Other cutans may describe compositional variations. Cutans may be identified in a paleosol or soil under the optical microscope. See pedofeature :

– argillan : An (oriented) clay coating over grains, voids, or aggregates. Compositional characteristics may be used as prefex modifiers, as “ferri-argilan” (iron oxide stained) or “organo-argillan” (stained by organic matter). See cutan, pedofeature, ferran, mangan. Syn., clay skin.

– calcan : A cutan composed of calcite.

– ferran : A cutan of iron oxide and hydroxide

– mangan : A cutan of manganese oxide and hydroxide

– organan : A cutan composed of organic matter

– silan : A cutan formed of opal or chalcedony

– sesquan : A cutan composed of Al-Fe oxides

– soluan : A cutan of soluble salts (e.g. gypsum)

A poorly defined material, possibly muscovite and albite.