Stoops and Jongerius (1975) differentiated five characteristic types (e.g., fabrics) of soil and palustrine deposits based on coarse (c) and fine (f) or clay particles: monic, gefuric, cithonic, enaulic, and porphyric. The c/f related distribution is therefore the relationship between ground mass (matrix) and a general framework of coarser components (e.g. grains, aggregates). The different descriptions of the classifications, however, are not mutually exclusive:

– cithonic c/f-related distribution : A distribution where fine-grained material forms a wrap over the coarser skeletal components. Any orientation of the clay particles in the wrap or cover are not considered important in the definition.

– enaulic c/f-related distribution : A distribution where there is a framework of grain- supported skeletal components with partial infillings of fine grained materials and pore spaces.

– gefuric c/f-related distribution : The distribution involves fine-grained material connecting coarser components, where coarse material is not in direct contact with other coarse components.

– monic c/f-related distribution : This distribution consists of predominantly one size group, including all ground mass, amorphous material or skeletal components.

– porphyric c/f-related distribution : The distribution of generally coarse components within a ground mass of fine-grained material.

An obsolete varietal term for biotite.

See reyerite group.

To heat a substance to a temperature where it dissociates, for example the heating of calcite (CaCO₃) to form CaO and CO₂. If clay is calcined, hydroxyl groups are removed from structural constituents and plasticity is destroyed.

An obsolete varietal term for biotite.

An obsolete varietal term for clintonite.

CAH phases are widely used in the Portland cement industry to enhance the hardening effect of Portland cement. For example, “celite” (Ca₃Al₂O₆, “C₃A”) is a non-hydrated calcium aluminate and a CAH phase, as is tetracalciuminate (Ca₄Al₂O₇. 19H₂O), a hydrated CAH phase. Lime (CaO) has been used for centuries as a stabilizer for soft clay treatment and improvement. It is generally believed that lime can slowly react with clay minerals to produce CSH and CAH phases that act as binders to contribute to the strength development of clayey soils. Cf., calcium silicate hydrate (CSH) phases

Calcium silicate (CS) phases are common to clinker. CS phases are mainly formed by heating calcium carbonate (e.g., limestone for Ca) together with aluminum silicate (e.g., any available clay minerals for Si, Al) phases to temperatures to >1200^oC. In practice, often marls, which are low in cost, are used as they combine carbonates and 2:1 layer phyllosilicates. Typical CS phases are “alite” (Ca₃SiO₅, “C₃S”), “belite” (Ca₂SiO₄, “C₂S”), or “celite” (Ca₃Al₂O₆, “C₃A”). These phases are responsible for the hardening effect of cement as they hydrate under the addition of water forming CSH phases.
Cf., calcium silicate hydrate (CSH) phases, clinker

CSH phases are formed from calcium silicate (CS) phases [e.g., “alite” (Ca₃SiO₅, “C₃S”), “belite” (Ca₂SiO₄, “C₂S”), jennite (Ca₉Si₆O₁₈(OH)₆·8H₂O) and tobermorite (Ca₅Si₆O₁₆(OH)₂·4H₂O or Ca₅Si₆(O,OH)₁₈·5H₂O)] by hydration, and these phases are responsible for the hardening effect of cement. Common CSH phases are calcium silicate hydrate (CSH) and ettringite (Ca₆Al₂[(OH)₁₂(SO₄)₃] . 26H₂O). Lime (CaO) has been used for centuries as a stabilizer for soft clay treatment and improvement. It is generally believed that lime can slowly react with clay minerals to produce CSH and CAH phases that act as binders to contribute to the strength development of clayey soils.
Cf., calcium aluminate hydrate (CAH) phases, clinker, calcium silicate (CS) phases, hardening

A commercial product consisting of sodium phosphate sometimes used as a dispersing agent for clays in aqueous suspensions. In this application, sodium phosphate buffers the solution and phosphate ions preferentially adsorb to clay edges. Both processes aid in dispersion of the clay. Calgon® is a registered trademark of The Calgon Corporation.