Serpentine carbonation could provide a safe, and environmentally friendly, opportunity to store the amount of anthropogenic CO2 emission necessary to meet the Paris Agreement target and limit global warming to a safe level for humanity. Mineral carbonation relies on the reaction of CO2 with cations abundant in ultramafic rocks (e.g. Mg2+) to form carbonate minerals (\citealp{Kelemen_2019}). Serpentinites are an ideal starting material because they are abundant on or near the Earth’s surface and are rich in Mg2+, which is required to form carbonates, primarily magnesite (MgCO3) that traps CO2 (\citealp{Lackner_1995}). This process stores CO2 in a solid state with no risk of release and has large storage capacity. Even if this technique is promising, it is at a lower stage of readiness and is yet to be applied at the industrial scale.The Ligurian ophiolites (Italy) host several magnesite deposits that formed when deep CO2 was injected into serpentinite lenses through regional faults at 100-200°C and depths of 1-2 km (\citealp{Rielli_2022}, \citealp{Boschi_2009}). These deposits effectively resemble the in-situ storage of CO2 by “natural pilot plants” active millions of years ago, where seemingly the conditions where fine-tuned to best sequester CO2. Thus, they provide a fast lane for understanding the best conditions for serpentinite carbonation.The PRIN 2022 PNRR STORECO2 project (granted by the European Union—NextGeneration EU) aims to understand these conditions through a geochemical, petrological and mineralogical study of the Castiglioncello magnesite deposit (Tuscany, Italy). Developing a deeper understanding on carbonation processes through the study of natural analogues, discussed in this work, we will able also to predict what to expect when CO2 is injected into serpentinites.
