Marathon Fusion, a San Francisco-based startup, has claimed a breakthrough in turning mercury into stable gold using fusion-generated neutrons. The company asserts its process is 10 times more efficient than a record set by CERN in 2025, though it has not disclosed the quantity of gold produced or its commercial viability. The announcement has reignited debates about whether lab-made gold could disrupt the precious metal's market, similar to how lab-grown diamonds impacted the diamond industry.
The process involves nuclear transmutation, where high-energy neutrons from a deuterium-tritium fusion reaction convert mercury-198 into mercury-197, which then decays into gold-197. While the underlying physics is sound, scaling this experiment into a commercially viable operation remains uncertain. Marathon Fusion also highlighted progress in producing medical isotopes and surpassing a 40-year-old Soviet record in isotope separation.
In a 2025 research paper, Marathon Fusion estimated that a fusion plant could produce about two tonnes of gold annually per gigawatt of thermal power. However, matching global mine production of 3,672 tonnes in 2025 would require an enormous 1,836 gigawatts of thermal power, assuming the model's projected output. The company has not demonstrated the reactor capacity or infrastructure needed to achieve this scale.
Experts caution that even if the technology succeeds, its impact on gold prices would depend on production costs, capacity, and managing radioactive byproducts. Tushar Jain of Multicoin Capital questioned whether artificially produced gold could affect the market, though the processes differ significantly from lab-grown diamonds.