Mineral physics is rapidly emerging as a coherent discipline of the earth sciences. It is dedicated to the understanding of how the physical and chemical properties of minerals control their geological behavior, especially at high pressure and temperature. Objectives of mineral physics include understanding properties of minerals on an atomic scale and using them to constrain the interpretation of global processes. Mineral physics provides the essential link between what we observe (e.g., seismic profiles) and what we would like to know (e.g., composition and temperature).