Porosity in minerals

Minerals typically form porous assemblies with porosity extending from a few percent to ca. 35% in porous sandstones, and over 50% in tuff, clays, and tuff. While transport of gases and liquids are widely researched in these materials, much less is known about their mechanical behaviour under stress. With the development of artificial porous materials such questions become more pertinent, e.g., for applications as fillers in car bumpers and airplane wings, and nanoscale applications in memistors and neuromorphic computers. This article argues that elasticity and related dielectric and magnetic properties can be described‑to some extend-as universal in porous materials. The collapse of porous materials under stress triggers in many cases avalanches of collapsed regions which are scale invariant and follow irreversible power law energy emission. Emphasis is given to a recent simple collapse model by Casals and Salje which covers many of the observed phenomena.