Magnetic Properties of Rocks and Minerals

This chapter describes the current state of the art in the field of computational and experimental mineral physics, as applied to the study of magnetic minerals. This chapter is divided into four sections, describing new developments in the study of mineral magnetism at the atomic, nanometer, micrometer, and macroscopic length scales. We begin with a description of how atomistic simulation techniques are being used to study the magnetic properties of mineral surfaces and interfaces and to gain new insight into the coupling between cation and magnetic ordering in Fe-Ti-bearing solid solutions. Next, we review the theory of off-axis electron holography and its application to the study of magnetotactic bacteria and minerals containing nanoscale transformation-induced microstructures. Then, we review the theory and application of micromagnetic simulations to the study of nonuniform magnetization states and magnetostatic interactions in minerals at the micrometer length scale. Finally, we review recent developments in the use of macroscopic magnetic measurements for characterizing and quantifying the microscopic spectrum of coercivities and interaction fields present in rocks and minerals.