Claysvary

Claysvary is a term used in geology and materials science to denote a proposed index of variability in clay-related properties within a given body of material, such as a sedimentary layer, a clay seam, or a manufactured batch. The concept focuses on quantifying how clay content and behavior vary across space or along a sample.

Definition and scope: Claysvary encompasses both the magnitude of variability in clay fraction and in clay-induced properties such as plasticity, swelling potential, and mineralogical composition. It can be expressed as a single dimensionless score or as a set of statistics derived from subsample measurements.

Calculation and methods: Sampling strategy; measurements of clay content (loss on ignition, X-ray diffraction for mineralogy), swelling tests, standard tests; Statistical methods: coefficient of variation, standard deviation, and geostatistical tools like variograms. A composite claysvary index can be created by normalizing different parameters and combining them with weights.

Applications: In mining and ceramics, claysvary helps assess process variability, predict handling properties, and optimize grinding, milling, or mixing. In soils and geotechnical engineering, it informs risk assessment for swelling clays and foundation design.

Limitations: Requires representative sampling; sensitivity to measurement methods; interpretation depends on the chosen parameters and weighting; not yet standardized.

See also: clay mineralogy, geostatistics, swelling clays, Atterberg limits.