July 31st, 2025
In Hellenistic Egypt more than 2,000 years ago, alchemists began their fabled quest to turn mercury into gold. Today, a California-based startup believes it may have finally cracked the code — using the power of nuclear fusion.
Marathon Fusion, a company developing next-generation fusion technology, has outlined a bold plan to create gold as a byproduct of clean energy generation. According to a newly released (and yet-to-be peer-reviewed) study, their reactor design could transmute mercury-198 — an abundant isotope — into gold-197, the stable form of the precious metal. (Gold and mercury happen to be next-door neighbors on the Periodic Table of Chemical Elements.)
The process takes place inside a tokamak fusion reactor, where ultra-hot plasma fuses hydrogen atoms to release vast amounts of energy. Typically, reactors are lined with lithium in what’s called a breeding blanket, designed to help generate tritium fuel.
But Marathon’s twist? Replace part of that blanket with a mercury-lithium alloy, which not only supports fusion fuel production but also absorbs high-energy neutrons. Those neutrons trigger a chain reaction that converts mercury-198 into unstable mercury-197, which decays into gold-197 within days.
In simulations, Marathon estimated that one gigawatt of fusion electricity could yield as much as 5,000 kilograms of gold. At today’s gold prices, that’s more than half a billion dollars in byproduct revenue, potentially doubling the economic viability of fusion plants.
There’s a catch, however: Freshly created gold atoms might carry trace radioactivity, requiring up to 18 years of “cooling time” before being deemed safe for commercial use. Still, the company argues that much of the world's gold sits in storage anyway, and delayed access won’t hinder its value in the long run.
Though still in the simulation phase, this proposal has captured the imagination of scientists and investors alike. If successful, it could reshape both the energy and precious metal industries of the future — replacing gold mines with clean fusion facilities, and turning modern science into the ultimate alchemy.
Credit: AI-generated image by The Jeweler Blog using ChatGPT and DALL-E 3.
Marathon Fusion, a company developing next-generation fusion technology, has outlined a bold plan to create gold as a byproduct of clean energy generation. According to a newly released (and yet-to-be peer-reviewed) study, their reactor design could transmute mercury-198 — an abundant isotope — into gold-197, the stable form of the precious metal. (Gold and mercury happen to be next-door neighbors on the Periodic Table of Chemical Elements.)
The process takes place inside a tokamak fusion reactor, where ultra-hot plasma fuses hydrogen atoms to release vast amounts of energy. Typically, reactors are lined with lithium in what’s called a breeding blanket, designed to help generate tritium fuel.
But Marathon’s twist? Replace part of that blanket with a mercury-lithium alloy, which not only supports fusion fuel production but also absorbs high-energy neutrons. Those neutrons trigger a chain reaction that converts mercury-198 into unstable mercury-197, which decays into gold-197 within days.
In simulations, Marathon estimated that one gigawatt of fusion electricity could yield as much as 5,000 kilograms of gold. At today’s gold prices, that’s more than half a billion dollars in byproduct revenue, potentially doubling the economic viability of fusion plants.
There’s a catch, however: Freshly created gold atoms might carry trace radioactivity, requiring up to 18 years of “cooling time” before being deemed safe for commercial use. Still, the company argues that much of the world's gold sits in storage anyway, and delayed access won’t hinder its value in the long run.
Though still in the simulation phase, this proposal has captured the imagination of scientists and investors alike. If successful, it could reshape both the energy and precious metal industries of the future — replacing gold mines with clean fusion facilities, and turning modern science into the ultimate alchemy.
Credit: AI-generated image by The Jeweler Blog using ChatGPT and DALL-E 3.
