Marathon Fusion says it made gold from mercury; Armstrong cites Bitcoin's 21M cap
In brief
- Marathon Fusion claimed it produced gold from mercury through nuclear transmutation, not chemistry.
- Marathon Fusion cited a rate 10 times CERN's record but hasn't disclosed the quantity.
- Marathon Fusion's paper projects about two tonnes of gold annually per gigawatt of thermal fusion power.
- Coinbase CEO Brian Armstrong said nothing can increase Bitcoin's 21 million supply.
- Metals Focus said the process is nowhere near production significance.
How Marathon says it works
Marathon's research paper describes high-energy neutrons from a deuterium-tritium fusion reaction irradiating mercury-198, producing a radioactive isotope that decays into stable gold-197. It's nuclear transmutation. There's no chemical trick involved.
The company said it produced stable gold at a rate 10 times CERN's record. For comparison, CERN's ALICE experiment produced an estimated 29 picograms of gold nuclei during its 2015-2018 run (and those nuclei existed only for fractions of a second). Marathon hasn't publicly stated how much gold its own experiment produced.
Research engineer Jake Harter told Magazine the quantities remain microscopic, and that the company hopes to reach milligram quantities in 2027.
Projections, not output
The bigger numbers in Marathon's paper are projections for a future fusion power plant, not today's output. The paper models about two tonnes of gold per gigawatt of thermal fusion power annually. For scale, the World Gold Council says global mines produced 3,672 tonnes of gold in 2025.
Even those targets aren't close. Harter said Marathon would need to scale production of the enriched mercury it uses and build a fusion reactor to reach them.
Nikos Kavalis, managing director at precious metals research firm Metals Focus, wasn't convinced:
“We are nowhere near a stage where we can talk about production significance.”
The Bitcoin argument
Armstrong compared the creation of new gold to the lab-grown diamond industry, where wholesale prices have fallen by more than 90% since 2018 as production scaled up, according to Cointelegraph Magazine. His point was supply. Armstrong said nothing can be invented to increase Bitcoin's supply, which is capped at 21 million.
Marathon co-founder and CEO Kyle Schiller, meanwhile, said he's been fielding a lot of interest from jewelers.
Magazine's own assessment splits the question in two: the underlying nuclear process is scientifically plausible, but turning it into an economical industrial process is a separate challenge. Kavalis said the process is nowhere near production significance, and Marathon's next stated milestone, per Harter, is milligram quantities in 2027.
Frequently asked questions
How does Marathon Fusion say it turns mercury into gold?
According to Marathon's research paper, high-energy neutrons from a deuterium-tritium fusion reaction irradiate mercury-198. That produces a radioactive isotope which decays into stable gold-197. It's a nuclear transmutation process, not a chemical one.
How much gold has Marathon Fusion actually produced?
Marathon hasn't publicly stated the exact quantity. It said it produced stable gold at a rate 10 times CERN's record, and research engineer Jake Harter said quantities remain microscopic. The company hopes to reach milligram quantities in 2027.
Could fusion-made gold meaningfully add to global gold supply?
Marathon's paper projects about two tonnes of gold per gigawatt of thermal fusion power annually for a future plant, compared with 3,672 tonnes mined globally in 2025 per the World Gold Council. Metals Focus's Nikos Kavalis said the process is nowhere near production significance.
