Earth's formation through accretion of primordial and differentiated material, led to extensive melting, resulting in multiple global magma oceans and differentiation into several layers, including metallic core and silicate mantle. These processes were extremely complex and shaped our Earth and the other terrestrial planets in very unique ways. Luckily, it has left behind geophysical and geochemical signatures preserved to this day in both, the core and the mantle. By studying Earth's structure, composition and dynamics, we attempt to understand more about its past by testing different evolution scenarios which might have led to formation of such a fascinating and diverse planet, that we live on.

Firstly, an experimental investigation of the two eutectics: periclase and bridgmanite (model peridotite) and bridgmanite and stishovite (model basalt) in the simplest MgO-SiO2 system which captures the major mineralogy of the lower mantle will be discussed in the context of understanding present-day Earth's structure and composition, but also its evolution through time since the earliest stages of its accretion and differentiation. Secondly, metal-silicate partitioning behaviour of Ge and Ga will be presented as the geochemical indicators of the Earth's core and mantle equilibration processes in the deep and hot magma ocean. Various experimental setups of the laser-heated diamond anvil cell (LH-DAC) technique presented in this study will be discussed together with the newest development of the novel metal-encapsulation method designed to provide more controlled and uniform temperature distribution in the LH-DAC experiments. Technological development, preliminary results and numerical thermal distribution model which enables estimations of the internal temperature gradients in the new experimental setup will be shown together with some future approaches to achieve entirely isothermal conditions at extreme pressures and temperatures of the planetary interiors.