Geothermometry and geobarometry in metamorphic rocks. Phase equilibrium studies. Extraction of thermodynamic data for minerals. Internally consistent datasets. Mixing models for non-ideal solid solutions. Multi-site solutions, site geometries and ordering. Phase separation in solutions. First- and second-order phase transformations. Kinetics of metamorphic reactions. Geospeedometry. Algebraic calculations for projective analysis. Schreinemakers analysis and petrogenetic grid. Construction of P-T, T-X, and P-X diagrams. Pseudobinary sections. Equilibria involving a multicomponent fluid phase. Buffering and infiltration. Characterisation of fluid composition through mineral equilibria.