1. The study of the physical behaviour of rocks, including crushing, bending, and shear-strength testing, and also their elasticity, internal angle of friction, density, permeability, and porosity. See elastic deformation; elastic limit.

2. In geology, the study of the mechanics of rock structures, their physical properties, and forces acting on strata.

3. In engineering, the study of rocks as raw materials, and their behaviour in tunnels, quarries, and mines; and the stability of buildings on rock foundations.