Concentration flows. 230 years in the crystallogenic agenda

We briefly outlined the history of discovery and study of concentration flows accompanying the growth and dissolution of crystals in solutions. Various crystallogenic consequences associated with concentration flows (changes in the mechanisms of transport of matter to the growing crystal, differences in the growth of the upper and lower faces, distortion of crystal shape, occurrence of hydrodynamic boundary layer around a crystal together with the diffusion layer, etc.) were described. The phenomenon of concentration differentiation (stratification) of the solution under the influence of concentration flows was especially analyzed. The criteria conditions for differentiation of the solution during crystal growth were determined.