ABSTRACT
Recent research shows that the rocks should be analyzed more completely and their microstructure and mineralogical composition taken into account in order to correctly characterize their strength. Minerals are defined as natural solids formed by predominantly inorganic processes, but also in rare cases organic processes. The crystalline arrangement of atoms depends primarily on their relative sizes and their chemical bonds. The electrons in the outer layers of the two atoms orbit around the two atoms indiscriminately, simultaneously completing two external orbitals without any gain or loss of electrons. The atomic arrangements along the various lattice planes give rise to an anisotropy of some properties. The directions of the lattice planes play a fundamental role in crystal growth and in the way crystals break when they are subjected to mechanical stress. An object has a plane of symmetry if it remains the same after reflection through this plane.
