Volume 17 of Reviews in Mineralogy is based on a short course, entitled "Thermodynamic Modeling of Geological Materials: Minerals, Fluids amd Melts," October 22-25, 1987, at the Wickenburg Inn near Phoenix, Arizona. Contents: Thermodynamic Analysis of Phase Equilibria in Simple Mineral Systems Models of Crystalline solutions Thermodynamics of Multicomponent Systems Containing Several Solid Solutions Thermodynamic Model for Aqueous Solutions of Liquid-like Density Models of Mineral Solubility in Concentrated Brines with Application to Field Observations Calculation of the Thermodynamic Properties of Aqueous Species and the Solubilities of Minerals in Supercritical Electrolyte Solutions Igneous Fluids Ore Fluids: Magmatic to Supergene Thermodynamic Models of Molecular Fluids at the Elevated Pressures and Temperatures of Crustal Metamorphism Mineral Solubilities and Speciation in Supercritical Metamorphic Fluids Development of Models for Multicomponent Melts: Analysis of Synthetic Systems Modeling Magmatic Systems: Thermodynamic Relations Modeling Magmatic Systems: Petrologic Applications