To fully understand Earth’s carbon cycle, it is necessary to take the fluxes from Earth’s crust into the mantle and between regimes in Earth’s interior into account. The transport and storage of carbon in form of carbonates into Earth’s interior might have a major effect on the carbon budget at the surface. But still the influence and stability of carbonates in Earth’s mantle is still not well understood. The phase behaviour of $CaCO_{3}$ in presence of mantle silicates at mantle conditions has only been investigated by simulations. In this thesis I experimentally approached the stability of this carbonate in presence of the most common mantle silicate, Bridgmanite. By using laser heated diamond anvil cells and synchrotron radiation induced micro X-ray diffraction, we collected data in situ and after temperature quenching at 24 to 35 GPa and 1300 to 2200 K to experimental mimic conditions of Earth’s lower mantle. Taken the geotherm of Earth’s mantle and of cold subducted slabs into account, it can be concluded, that in fact it is possible to have metastable $CaCO-{3} – VII$ in the lower mantle besides Bridgmanite. This result is in agreement with recent studies.