🇮🇸 Natural ‘fingerprints’ show captured CO2 is permanently locked into rock at Iceland site

March 5, 2026

Researchers tracked what happened to injected CO₂ at mineralisation operator Carbfix’s storage site in Iceland by analysing tiny, naturally occurring differences in the types of carbon, water, and noble gases in the system. The CO₂ was dissolved in water, injected deep into basalt rock, and then monitored over time using these natural chemical signatures.

Samples from underground monitoring points showed the CO₂ reacting with the rock to form solid carbonate minerals. The study, published in the International Journal of Greenhouse Gas Control and funded by the Natural Environment Research Council (NERC), demonstrates that using inherent isotopes and gases could offer a robust, lower-intervention monitoring and verification (MRV) tool for commercial CO₂ storage. Overall, the monitoring data lined up with mineralisation levels previously reported at the Carbfix site, adding weight to earlier evidence that the process is fast and secure.

“We can use the natural fingerprints already present in the CO₂ and water to track when CO₂ dissolves and turns to stone, without adding anything extra underground,” says Dr Chris Holdsworth, lead author of the study and MRV technical specialist at Carbfix. “This approach not only simplifies monitoring but also ensures that the CO₂ is permanently and safely stored as solid minerals.”

The findings align with previously reported mineralisation rates at Carbfix, reinforcing evidence that the process can be both rapid and durable. The study, titled ‘Monitoring CO₂ mineralisation and dissolution at CarbFix2 using inherent isotopes of CO₂, H₂O and noble gases,’ is published in the International Journal of Greenhouse Gas Control.

Carbfix’s technology involves dissolving CO₂ in water and injecting it into basalt formations, where it reacts with the rock to form carbonate minerals—effectively turning CO₂ into stone. This method has been proven to mineralise over 90% of injected CO₂ in less than two years, offering a permanent and secure solution for carbon storage.

The study was conducted in collaboration with the University of Edinburgh and highlights the potential of using natural chemical signatures for monitoring CO₂ storage, reducing the need for artificial tracers and simplifying the verification process.

For more information, visit Carbfix.

Originally published on March 5, 2026 by Carbfix.