This paper reviews transformations and properties of minerals and rocks under lower mantle conditions. It is likely that most of the lower mantle consists of three minerals; orthorhombic perovskite in the system (Mg, Fe)SiO3-Al2O3, cubic perovskite CaSiO3, and magnesiowuestite (Mg, Fe)O, with the composition slightly enriched in Fe and Si compared to the upper mantle. Transformation in subducted oceanic crust at lower mantle conditions, which is crucial for under-standing the dynamics of the mantle, is still unclear.
