An obsolete term for celadonite.

A method of measuring intramolecular or intracrystalline modes of motion (vibrational modes) by observing the interaction of incident radiation with a sample. Common techniques used to obtain spectra are infrared and Raman spectroscopy, and inelastic neutron scattering.
Cf., spectroscopy, normal mode

The measured hardness of a surface as tested using a special diamond pyramid-shaped indenter under various loads. A Vickers number is reported based on surface area indented (in mm²) divided by pressure (in Newtons).
Cf., hardness, Mohs hardness

A general term used in the pelotherapy clay industry to denote an unmodified (“raw”) clay from a deposit, before maturation with saline or mineral water.

An obsolete term for an iron-rich chlorite.

A measure of the resistance of a fluid to flow when the fluid is placed under stress.

An obsolete term for a mixture of allophane and wavellite from Santa Rosa de Viterbo, Colombia.

Glassy luster.
Cf., luster

The process of changing a solid, often crystalline material, into an amorphous glass-like material by heating the solid to its melting point followed by sufficiently rapid cooling and solidification so that short-distance atomic ordering resulting in recrystalization does not occur. As vitrification proceeds, the porosity decreases. Devitrification is the reverse process.

The ratio of the empty space (void volume) of a soil or geomaterial to the volume of its solid particles.
Cf., porosity