The text describes the changes that occur in rocks due to hydrothermal alteration, a process where physical disequilibrium generated by circulating hydrothermal solutions leads to mineralogical and chemical changes within the rocks. The solutions migrate through the rock's spaces, including small fractures, pores, and cavities, and incorporate ions released from dissolved minerals while losing chemical components. This results in unique characteristics at each point due to differences in temperature, pressure, and hydrostatic potential. By recognizing associations between minerals and textures, geologists can identify the conditions under which these alterations formed. The presence of moscovite, a mineral with high interference colors visible through microscopy, suggests that the rock was initially without moscovite but has since been impregnated with it as a result of hydrothermal solutions. These alterations provide a guide for exploring mineral deposits and understanding the characteristics and reactions of hydrothermal solutions.