This review presents a recent progress in theoretical analysis of non-equilibrium textures in rocks. Classical irreversible thermodynamics provides a powerful tool for the analysis in a linear non-equilibrium regime not far from equilibrium. First we discuss the rate-determining processes and resulting non-equilibrium textures based on Fisher's method. This analysis clarifies the relationship between three rate-determining processes: the diffusion-controlled, the reaction-controlled, and the heat-flow-controlled processes in metamorphism. Discussions extends into characteristics of various non-equilibrium textures such as reaction zones, composite veins, oscillatory zoning, comb layering, and metamorphic layering. Strategies for the analysis of these non-equilibrium textures and what informations we can get from them are also discussed. Finally, the most successful method for the analysis of diffusion-controlled structures developed by Fisher and Joesten, the steady diffusion model, is explained in detail, and the application to a natural example, an olivine-plagioclase corona, by Nishiyama is summarized. Steady state coupling of diffusional fluxes and chemical reactions at the layer contacts reduces to mass balance relationships having phenomenological coefficients' ratios as unknown parameters. The parameters control the stability of zonal arrangements and also determine the exchange relationships of diffusing components between mineral layers.
