Key facts
- Marathon Fusion claims to have transmuted mercury into stable gold.
- The company claims its method beats CERN's 2025 record by a factor of 10.
- Lab-grown diamonds' price fell significantly due to factory production.
- De Beers' natural diamond business reported a $511 million loss in 2025.
- Gold traded at $4,062 an ounce on Thursday.
San Francisco-based start-up Marathon Fusion announced on Wednesday that it has successfully transmuted mercury into stable gold, claiming to have achieved this at ten times the rate of a previous record set by CERN. The company's claim, which has not been independently verified, evokes the historical dream of alchemy and raises concerns about the potential impact on the gold market, similar to how lab-grown diamonds affected the natural diamond trade.
Founded in 2023 by Kyle Schiller and Adam Rutkowski, Marathon Fusion develops fuel systems for fusion power plants. The company is backed by Breakthrough Energy, founded by Bill Gates, and mining group Anglo American, which owns De Beers. Marathon stated it turned mercury into "real, stable gold," surpassing CERN's 2025 report of creating approximately 29 picograms of gold using its Large Hadron Collider.
Marathon's method involves firing neutrons from fusion reactions at mercury, converting it into an unstable isotope that decays into gold. The company also claims to have broken a Soviet record with its plasma centrifuge. However, the amount of gold produced and its cost remain unestablished, and the material could contain radioactive isotopes requiring up to 18 years of storage before sale.
The impact of lab-grown diamonds, which are chemically identical to mined stones, led to a 90% to 95% drop in wholesale prices from 2015 levels, according to diamond industry analyst Paul Zimnisky. De Beers, a major player in the natural diamond market, experienced an underlying loss of $511 million in 2025 and is reportedly in talks to sell its stake in the company.
Gold, a significantly larger market than diamonds, saw production of 3,672 tonnes in 2025. Central banks have been increasing their gold reserves. Gold traded at $4,062 an ounce on Thursday, more than 27% below its January record high. Marathon Fusion estimated that a fusion plant could produce about 5 tonnes of gold annually per gigawatt of electricity, but commercial fusion power plants are still years away from operation.