From Alchemy to Economics: Synthetic Gold at 850 Dollars an Ounce May Reshape Markets

Marathon Fusion’s claim that it can produce stable gold from mercury-198 through neutron transmutation could structurally alter, albeit over the long term, the gold revaluation thesis advocated by State Street/Miran.

The physics is considered sound: the (n,2n) reaction, triggered by 14.1 MeV neutrons produced by D-T fusion, can generate stable gold-197 through the beta decay of mercury-197. However, Marathon’s demonstration has not been independently verified.
The main obstacle remains economic. The estimated production cost of 850 $/oz would be below the average mining AISC of 1930 $/oz and the spot price of 4 166 $/oz in October 2026.
However, a $3 billion reactor rated at 1.5 GWth and isotope separation, estimated at 2.4 $/kg of Hg-198, represent significant barriers to entry.
By 2030–2040, the impact on supply would remain limited: a 1 GWth reactor would produce approximately 2 tonnes of gold per year. Even 50 reactors by 2040 would add approximately 100 tonnes annually, equivalent to 2% of global mine production of 5,000 t/year.
The estimated cumulative price decline of 4–8% would not be sufficient to invalidate a trajectory toward $10,000.
On a larger scale, however, hundreds of GWth could establish a technological floor for the price of gold and reduce its monetary premium associated with physical scarcity. This scenario, unlikely before 2050, warrants monitoring and partial diversification into Bitcoin.
Finally, the accounting revaluation of Fort Knox gold from 42.22 $/oz to 4 166 $/oz would generate approximately $1,050 billion in liquidity, independently of supply.
Nevertheless, gold’s credibility as the ultimate reserve asset could erode over the long term, contingent on technological maturity that remains uncertain.
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1. Marathon Fusion (2025). Scalable Chrysopoeia via (n,2n)(n,2n) Reactions Driven by Deuterium-Tritium Fusion Neutrons. arXiv:2507.13461.
2. Marathon Fusion (2026). Self-subsidizing Mercury Remediation with Fusion Reactors. arXiv:2604.02590.
3. CNBC TV18 (2026, 22 octobre). Marathon Fusion claims it can turn mercury into gold: Could it crash gold prices?.
4. The Oregon Group (2026, 22 octobre). Fusion start-up turns mercury into gold, but can’t say what it costs.
5. Euronews (2026, 23 octobre). Could lab-made gold crash prices like diamonds?.
6. Odaily (2026). Humanity’s tech tree has finally unlocked alchemy.
7. Hindustan Times (2026, 23 octobre). San Francisco startup Marathon Fusion claims it has turned mercury into gold.
8. World Gold Council (2026). Gold Demand Trends Q2 2026.
9. BIS (2026). Term Premium Analysis.
10. Zenodo (2026, avril). Gold Re-Anchor Matrix.