Experts urge caution over claim of turning mercury into gold

San Francisco-based Marathon Fusion announced on October 21 that it converted mercury into gold in a September experiment, at ten times the rate of a 2025 CERN record. It proposes exposing mercury-198 to fusion neutrons to form mercury-197, which decays into gold-197, predicting about 2 tonnes of gold a year per gigawatt of fusion power. The claim carries several caveats.