Rarе Fedorov groups in structural mineralogy

Abstract

The crystal order in structure of a solid phase is provided by the symmetry of interatomic interactions. In its turn, the latter causes the symmetry of atomic spatial positions, i.e. the spatial symmetry of the structure. From this viewpoint, the phenomenon of mineral formation can formally be considered as a result of ordering the atoms by the operations of spatial symmetry. This ordering is selective. Most mineral structures are described by minor formally possible spatial symmetry groups. The peculiarities of «structural preferences» of mineral phases during crystallization and re-crystallization are studied. The quantitative estimations for frequencies of Fedorov groups in crystal structures are given.