| Fusion energy start-up claims to have cracked alchemy |
San Francisco start-up says modified fusion process could be used to produce gold from mercury
 Marathon Fusion has raised about $4mn in US government grants for its plasma centrifuge © Marathon Fusion
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current progress 98%
Tom Wilson in London
Publishedan hour ago
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A fusion energy start-up claims to have solved the millennia-old challenge of how to turn other metals into gold.
Chrysopoeia, commonly known as alchemy, has been pursued by civilisations as far back as ancient Egypt. Now San Francisco-based Marathon Fusion, a start-up focused on using nuclear fusion to generate power, has said the same process could be used to produce gold from mercury.
In an academic paper published last week, Marathon proposes that neutrons released in fusion reactions could be used to produce gold through a process known as nuclear transmutation.
The paper has not yet been peer-reviewed but has had a positive reception from some experts in the field. “On paper it looks great and everyone so far that I talk to remains intrigued and excited,” Dr Ahmed Diallo, a plasma physicist at the US Department of Energy’s national laboratory at Princeton who has read the study, told the Financial Times.
Marathon was founded in 2023 by chief executive Kyle Schiller and chief technology officer Adam Rutkowski, both 30, as an engineering company aiming to solve some of the technical challenges of building fusion power plants.
 Marathon chief technology officer and co-founder Adam Rutkowski presents to Bill Gates at the 2024 Breakthrough Energy Summit in London © Marathon Fusion
The start-up, which has 12 full-time employees, has raised $5.9mn in investment and about $4mn in US government grants to date. Initially the team worked on challenges such as how to make the fuel burning system in a fusion power plant more efficient and started thinking about the possibilities of nuclear transmutation earlier this year, Rutkowski said.
Scientists have synthesised gold using particle accelerators but the amounts have been tiny and the costs extremely high. Earlier this year physicists at Europe’s Cern said they had observed lead atoms transforming into gold during high-speed near-collisions inside the Large Hadron Collider.
The most common experimental approach to fusion uses a device called a tokamak to heat two hydrogen isotopes — usually deuterium and tritium — to extreme temperatures so that they fuse to create helium and vast amounts of energy in the form of neutrons.
Most plans for potential fusion power plants aim to combine some of the neutrons with lithium isotopes in a “breeding blanket” to create more tritium for future reactions.
Marathon’s proposal is to also introduce a mercury isotope, mercury-198, into the breeding blanket and use the high-energy neutrons to turn it into mercury-197.
Mercury-197 is an unstable isotope that then decays over about 64 hours into gold-197, the only stable isotope of the metal.
Rutkowski and Schiller say this means future fusion power plants that adopt this approach would be able to produce 5,000kg of gold a year, per gigawatt of electricity generation, without reducing the power output or tritium-breeding capacity of the system. At current prices, they estimate that amount of gold would be worth roughly the same as the electricity being generated, potentially doubling the revenue of the plant.
“The key insight here is that you can use this set of fast neutron reactions to make really large quantities of gold while satisfying the fuel cycle requirements of the system,” said Rutkowski, who previously worked at SpaceX.
One complication is that the presence of other types of mercury is likely to result in the production of unstable gold isotopes alongside gold-197, meaning the metal could be partially radioactive. Rutkowski estimates this could mean the gold has to be stored for 14 to 18 years for it to be labelled completely safe.
The process could also be used to make other precious metals, but Marathon predicts that the size of the gold market means production from fusion reactions could be absorbed without hurting prices. Currently about 3,500tn of gold is mined every year.
“Gold is in that sweet spot,” said Dan Brunner, a former chief technology officer at Bill Gates-backed Commonwealth Fusion System, who is now a scientific adviser to Marathon. “From a purely scientific perspective, it looks like it all hangs together. I think the challenge comes into actually engineering it into a practical system.”
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Physicists first successfully fused atoms in the 1930s but no one has yet managed to produce more energy from a fusion experiment than the process consumes. Some scientists argue that fusion power plants remain decades away, however increased private investment in recent years has brought optimism. Commonwealth, for example, aims to turn on a demonstration power plant in 2027 and supply electricity to Google in the early 2030s.
In the 12 months to July fusion companies raised $2.6bn, bringing total investment to date across 53 companies worldwide to $9.8bn, according the most recent industry study, published on Tuesday.
Malcolm Handley, whose venture capital fund Strong Atomics was Marathon’s first investor, said the possibility of generating gold revenues from fusion power generation would unlock more funds for Marathon and other companies to accelerate their work.
Fusion companies had “signed up for a lot of hard problems”, he said. “The money this will unlock will make all of those problems easier.”
Graphics by Ian Bott
Copyright The Financial Times Limited 2025. All rights reserved.
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Well, if it works, the value of the gold will collapse and it is not necessarily going to be a good thing.
(Edited)
In a further refinement, the nucleotides can decay into Bitcoin!
It's this why people pay for FT subscriptions? To get PR releases presented as news?
Needs more AI
Hey guys, I heard you like vaporware, so I put vaporware in your vaporware.
Lovely graphics. Make sure Donny sees this.
$10m funding, fusion reaction, theoretical paper, alchemy, radioactive gold, they’ll be competing with asteroid mining on Saturns outer rings
Great, now just have fusion that has commercial sense: oh wait...
Finally something worthwhile to invest in besides bitcoin.
This is after the small matter of sorting fusion power, right?
Anyone who is excited is not very clever. This is old news and the catch is that it is probably still way cheaper to just mine it.
We do alchemy all the time in nuclear fission reactors but unfortunately the products are useless and radioactive.
At scale, gold will become worthless.
No! You debase gold, what am I left with?
Diamonds went a while a go with lab grown. I'm going to have to join thr crypto bros!
Go invest in biodiversity.
(Edited)
How did this deserve an FT article? Total $10m funding to date - one obscure academic article suggesting it might work.
"would be able to produce 5,000kg of gold a year, per gigawatt of electricity generation."
"Currently about 3,500tn of gold is mined every year."
If that was true it would mean 120MW power plant produces over 4,000 thousand tons of gold per year.
I think there is some confusion here in the reporting - or there will be a great many gold bugs hanging their heads.
1 Gigawatt = 1000 Megawatt
Isnt it per GW, not per GWH? So a 120 MW plant would produce 0.6 tonnes per year.
science: we could have free unlimited energy
Humanity: idk sounds expensive
science: yeah but what if it also made this shiny object?
Humanity: whoa! Someone call Bill Gates! Let’s fund this thing!
Are they having a Theranos moment (whilst fundraising)?
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