High-p3 pressure mineral physics investigates the properties of candidate components of the Earth deep interior and allows us to compare mineralogical models with both geochemical and geophysical constraints. The experimental techniques of mineral physics allow us to investigate the properties of a wide range of Earth materials. In this talk I will present selected results of my research regarding (a) the compositional dependence of elasticity in olivine and minerals of the upper mantle (b) the effect of the high-spin to low spin transition of Fe on the compressibility of (Mg,Fe)O ferropericlase at lower mantle pressures, (c) a possible mechanism for valence change of Fe in hydrous minerals in the subducting lithospheric slabs and upper mantle based on vibrational spectroscopy of Fe(OH)2.