RUI: Thermodynamic and Thermal Expansion Behavior of Mineral Systems

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This research seeks to understand how earth materials, and the earth itself, behave as a function of temperature and pressure. Such information allows prediction of the conditions under which the earth's minerals form and how their coexistence are interpreted. A significant number of studies have been developed specifically for undergraduate participation. These experiences teach students how research is conducted and why results are important in the context of ethical scientific behavior. Research involvement also is important to the enthusiasm of students for science and their retention in science. All but one of the students involved in past projects in this laboratory, more than 50% of them women, remain involved in science today. Additionally, it is important for any teacher to remain engaged in her/his discipline throughout a professional lifetime. The collective research experiences of a scientist enrich his/her professional life, but just as importantly benefit his/her students as a result of the knowledge, experience, and enthusiasm brought to the classroom.The principal purpose of this laboratory is the collection of thermodynamic data on geologically important materials utilizing acid solution calorimetric experimentation conducted at 50 °C. Such data contribute to determination of the conditions in the earth under which materials occur, even at great depths below the surface. One focus is on "thermodynamic mixing properties" of crystalline solutions, as relatively few directly measured thermodynamic data exist for mid-compositional members of mineral series. The latter are critical to thermodynamic modeling, and required for the accurate prediction of mineral occurrences for intermediate members of solid solution series. In addition, calorimetric data help clarify the fundamental energetic bases of mineral formation, knowledge that can be applied to additional materials whose thermodynamic properties have not been measured. A second component of this work involves undergraduate-oriented high-temperature X-ray investigations on the thermal expansion of minerals. These will yield information critical to understanding how mineral structures behave at the elevated temperatures that exist below the earth's surface. They also will contribute to an understanding of the mechanisms through which expansion takes place. Finally, the latter studies will yield volumes of mixing for mineral series as a function of temperature.