The objective of this research project is to synthesize Si-C-O-based minerals under extreme pressures and temperatures (several tens of GPa and thousands of degrees) and study in situ their structure stability and physical properties at Earth’s mantle conditions. Experiments will be performed using cutting-edge techniques such as diamond-anvil cells and high-power heating lasers together with concurrent complementary characterization techniques, such as Raman spectroscopy or x-ray diffraction in synchrotron radiation facilities. Recent results suggest that these two compounds, CO2 and SiO2, could react at high pressure-temperature. The model system SiO2-CO2 is, however, compositionally not representative of the Earth’s mantle. Thus, in a second stage we will undertake experiments in the more complex Mg-Si-C-O system. The resulting framework Si-C-O-based minerals could be potential candidates of major host of oxidized carbon in the Earth. The discovery of these compounds would give rise to a completely new class of oxides of great interest for Earth and materials sciences. The results will be compared with ab initio simulations, giving a detailed and consistent experimental and theoretical picture of HP-HT Si-C-O mineral physics. Our group has already performed a theoretical search finding two possible HP-HT thermodynamic stable polymorphs. The expected results will allow accurately determining the thermodynamic parameters at the carbonate-silicate stability boundaries which are crucial for understanding the nature of the carbonate-silicate geophysical cycle.In addition, the project seeks to setup a table-top mineral laser-heating facility in Valencia. Developments made could be later transferred to the high-pressure MSPD beamline at ALBA synchrotron. In summary, this Marie Curie IOF Fellowship will fund a high-risk/high benefit interdisciplinary project and will facilitate the definitive candidate’s transition to the high-quality European scientific workforce.