Optical properties of deep-Earth minerals

Earth's lower mantle contains vast amounts of rock, extending from just beneath the 660-km seismic discontinuity, all the way to the core-mantle boundary at 2900 km depth. Lower-mantle materials are essentially semiconductors, insulating enough to promote convective heat transfer from the core, but heat conduction is gaining recognition as an important control on geodynamic processes of the mantle at high pressure and temperature conditions. The optical properties of minerals, determined by light absorption experiments, provide information on the radiative component thermal conductivity (κrad). The radiative component heat transfer is generally dependent on temperature, pressure, and the electronic structure of iron doping.