Updated October 23, 2026 · 7 minute read
Quick answer
No, gold can't be grown the way diamonds are. And nothing about this week's news changes the jewelry you buy today.
Gold is an element. A diamond is carbon a lab can rearrange. Making gold means changing the atom itself with a nuclear reaction.
It's been done, barely. Scientists have made gold since the 1940s, but only in microscopic amounts at enormous cost.
The new claim. On October 21, 2026, Marathon Fusion said it turned mercury into stable gold at 10 times CERN's record rate. No amount or data has been published.
Nothing changes for you. Real volumes would need commercial fusion power plants, which don't exist yet.
Can gold be lab-grown like diamonds?
Not in the same way. Lab-grown diamonds are made by arranging carbon atoms into a diamond crystal, which is chemistry. Gold is a chemical element with 79 protons in every atom, so the only way to make it is to change one element into another through a nuclear reaction. That is possible, but so far only in tiny, extremely expensive amounts.
This question is suddenly everywhere because of a headline this week: a fusion energy company says it has turned mercury into real gold. As a lab-grown diamond jeweler, we get asked about "lab-grown everything" all the time, so here is a clear, no-hype look at what actually happened and what it means for the jewelry you buy.
Why diamonds can be grown but gold can't
The difference comes down to what each material is made of.
A diamond is pure carbon, the same element found in pencil graphite. What makes it a diamond is how the carbon atoms are locked together. Labs recreate the heat and pressure deep inside the Earth (the HPHT method) or build the crystal layer by layer from carbon-rich gas (the CVD method). The result is a real diamond, chemically and physically the same as one from a mine.
Gold is different. Every gold atom has exactly 79 protons in its nucleus. You cannot rearrange other atoms into gold. To make it, you have to add or remove particles from the nucleus of a neighbouring element, a process called nuclear transmutation. This is the old alchemist's dream, and it requires particle accelerators or nuclear reactors, not a jewelry lab.
| Compare | Lab-grown diamond | Lab-made gold |
|---|---|---|
| What it is | Carbon atoms in a crystal structure | An element (79 protons per atom) |
| How it's made | Chemistry: heat and pressure, or gas deposition | Nuclear physics: changing one element into another |
| Equipment | Diamond growing machines | Particle accelerators or nuclear reactors |
| Available to buy? | Yes, widely, for years | No. Only microscopic lab amounts so far |
| Same as the mined version? | Yes, chemically identical | Stable gold made this way would be identical, atom for atom |
What Marathon Fusion announced in October 2026
Marathon Fusion is a San Francisco start-up founded in 2023 that works on technology for fusion power plants. On October 21, 2026, it posted on X that it had demonstrated what it called "high-rate alchemy" the month before: turning mercury into real, stable gold at 10 times the rate of CERN's 2025 record.
Here is the announcement video Marathon Fusion shared with its post:
Last month, we demonstrated high-rate alchemy: turning mercury into real, stable gold, beating CERN's record by a factor of 10.
Marathon Fusion (@MarathonFusion) October 21, 2026
Video: Marathon Fusion on X, October 21, 2026. In it, the company describes its beam-driven fusion approach and shares simulation estimates of more than 2 tonnes of gold per year for each gigawatt of thermal power.
Here is what is important to know about the claim:
- No quantity was given. The company described a production rate, not how much gold it actually made.
- No full data has been published. As of this writing, the result has not been independently verified.
- The amounts are tiny. CERN's record, the benchmark Marathon compared itself to, produced about 29 picograms of gold over four years. A picogram is one trillionth of a gram, millions of times lighter than a single grain of sand. Ten times a microscopic rate is still microscopic.
- It builds on a 2025 paper. In July 2025, the company published a study estimating that future fusion power plants could make around 5,000 kilograms of gold per year for every gigawatt of electricity produced. That estimate came from computer modelling, and it depends on fusion power plants that have not been built yet.
So this is a genuinely interesting step from theory to experiment, but it is a long way from gold you could hold, let alone set a diamond in.
How does mercury turn into gold?
Mercury sits right next to gold on the periodic table, with one more proton. Marathon's method uses that closeness:
- Start with mercury-198, a stable form of mercury that makes up about 10% of natural mercury.
- Hit it with fast neutrons released by a fusion reaction. The impact knocks a neutron out, turning it into mercury-197.
- Wait. Mercury-197 is unstable. It naturally decays into gold-197 with a half-life of about 64 hours.
- The result is gold-197, the only stable form of gold and exactly the kind found in mined gold.
There is a catch. Natural mercury also contains other isotopes, which could create radioactive forms of gold mixed in with the stable kind. Marathon's 2025 paper suggested the gold might need to be stored for well over a decade before it could be sold, unless the mercury is carefully purified first.
Has anyone made gold before?
Yes, several times. Just never in a useful amount.
- 1941Researchers at Harvard bombarded mercury with neutrons and produced radioactive forms of gold.
- 1980Nobel laureate Glenn Seaborg's team turned bismuth into gold using a particle accelerator. The amount was a few thousand atoms, and the cost was far beyond the value of the gold.
- 2025CERN's ALICE experiment reported that lead collisions in the Large Hadron Collider had briefly created gold nuclei, about 29 picograms over its 2015 to 2018 run. Each nucleus broke apart almost instantly.
- 2026Marathon Fusion claims a 10 times faster rate than CERN, producing stable gold from mercury. Not yet independently verified.
Will lab-made gold make gold cheaper?
Not anytime soon. Even if Marathon's method works exactly as described, meaningful amounts of gold would only come from full-size commercial fusion power plants. Those are still in development, and the gold they produce might need years of storage before it is safe to sell.
Market analysts covering the announcement noted that the technology is at the lab demonstration stage, with output far below commercial scale, and has virtually no effect on gold prices in the near term. Gold's value today is driven by mining supply, central banks, investors and jewelry demand, none of which a lab experiment changes.
Could you tell lab-made gold from mined gold?
Once it is fully stable and purified, no. Gold has only one stable isotope, gold-197. A gold atom made in a reactor would be exactly the same as one dug from the ground or recycled from old jewelry.
That makes it very different from lab-grown diamonds. Gemological labs can identify whether a diamond was grown or mined from tiny growth patterns in the crystal, which is why lab diamonds come with their own certificates. Pure gold has no crystal "fingerprint" of its origin. So even in a distant future with fusion gold, you would not see a separate "lab gold" category in jewelry stores the way there is for diamonds.
What this means if you're buying a ring today
- There is no reason to wait. Lab-made gold is not on the market and will not be for many years, if ever.
- Your gold is real gold. 14K and 18K gold jewelry is valued the same way it has always been: by its purity and weight.
- The lab-grown choice that exists today is the diamond. Lab-grown diamonds give you a real diamond, identical to a mined one, at a far more accessible price.
- If sustainability matters to you, recycled gold is the most widely available eco-conscious option right now. It is refined from existing gold, so it is identical in quality and avoids new mining.
Quick quiz: how much do you know about lab-made gold?
Six quick questions. Tap an answer to see if you got it right.
1. What is a diamond made of?
Diamonds are pure carbon, the same element as pencil graphite. The difference is how the atoms are bonded together.
2. Why can't gold be grown in a lab the way diamonds are?
Diamond making is chemistry (rearranging atoms). Gold making is nuclear physics (changing the atom itself).
3. Which element did Marathon Fusion say it turned into gold?
Mercury sits right next to gold on the periodic table. CERN's experiment used lead, which is why both often appear in alchemy headlines.
4. About how much gold did CERN's Large Hadron Collider create over four years?
Roughly 29 trillionths of a gram, and every nucleus broke apart almost instantly. Not quite enough for a wedding band.
5. If fusion gold is ever made at scale, could a lab tell it apart from mined gold once it's stable and pure?
Gold has only one stable isotope, gold-197. Atom for atom, it would be identical.
6. What is the most practical eco-conscious gold choice available today?
Recycled gold is refined from existing gold, so it is identical in quality and avoids new mining. Fusion gold is still years away.
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Frequently asked questions
Is lab-grown gold real?
Not as a product you can buy. Scientists have made gold through nuclear reactions, but only in microscopic amounts. In October 2026, Marathon Fusion claimed it had turned mercury into stable gold, but it did not share how much it made, and the claim has not been independently verified.
Can scientists actually turn other metals into gold?
Yes. It has been done since the 1940s using nuclear reactors and particle accelerators, including bismuth into gold in 1980 and lead into gold at CERN in 2025. Every attempt so far has produced tiny amounts at a cost far higher than the gold's value.
Who is Marathon Fusion?
Marathon Fusion is a San Francisco start-up founded in 2023 that develops technology for future fusion power plants. In 2025 it published research proposing that fusion plants could produce gold from mercury as a by-product, and in October 2026 it announced a lab demonstration.
Will lab-made gold make gold prices drop?
Not in the foreseeable future. Producing meaningful amounts would require commercial fusion power plants, which do not exist yet. Analysts covering the announcement said it has virtually no near-term effect on gold prices.
Is gold made from mercury radioactive?
It can be at first. Natural mercury contains several isotopes, and some would create unstable, radioactive forms of gold alongside stable gold. The 2025 research suggested the gold might need to be stored for well over a decade before sale, unless the mercury is purified beforehand.
Are lab-grown diamonds and lab-made gold the same idea?
No. Lab-grown diamonds are made by arranging carbon atoms into a diamond crystal, a proven process that has been on the market for years. Lab-made gold requires changing one element into another through nuclear physics, which is still experimental.
Should I wait for lab-made gold before buying jewelry?
No. Lab-made gold is not available and is unlikely to be for many years. The gold in fine jewelry today is valued by its purity and weight, and if sustainability is important to you, recycled gold is an excellent option right now.
Lab-grown gold is still science fiction. Lab-grown diamonds are not.
Explore real diamonds, responsibly grown and handcrafted in solid gold.
