Scientists Show That the Earth's Interior Contains Vast Hidden Reserves of Gold and Precious Materials

The Earth's largest gold reserves are not located at Fort Knox, the United States Bullion Depository. In fact, they are hidden much deeper than one might expect.

More than 99.999% of Earth's gold and other precious metal reserves lie buried beneath 3,000 km of solid rock, locked away in Earth’s metallic core and far beyond humanity’s reach.

Now, researchers from the University of Göttingen have found traces of the precious metal ruthenium (Ru) in volcanic rocks from the Hawaiian Islands that must have originated from Earth’s core. The findings were published in Nature.

Origin of Gold and Other Precious Metals on Earth

Compared to the Earth’s rocky mantle, the metallic core contains a slightly higher abundance of a particular Ru isotope: 100Ru. This is because part of the Ru that was trapped in the Earth’s core along with gold and other precious metals when it formed 4.5 billion years ago came from a different source than the small amount of Ru found in the current mantle. These differences in 100Ru were so small that they were previously undetectable.

Now, new procedures developed by researchers at the University of Göttingen make them detectable. The unusually high 100Ru signal found in surface lavas can only indicate that these rocks originated at the core-mantle boundary.

Dr. Nils Messling from the Department of Geochemistry at the University of Göttingen explains: "When we received the first results, we realized we had struck gold. Our data confirmed that material from the core, including gold and other precious metals, is seeping into the Earth’s mantle."

Professor Matthias Willbold, from the same department, adds: "Our findings not only show that the Earth's core is not as isolated as previously thought. We can now also demonstrate that massive volumes of superheated mantle material (several hundred trillion metric tons of rock) originate at the core-mantle boundary and rise to the Earth's surface to form oceanic islands like Hawaii."

This means that at least a portion of the scarce supplies of gold and other precious metals we rely on for their value and importance in many sectors, such as renewable energy, may come from Earth's core.

Messling concludes: "It remains to be seen whether the processes we observe today were also active in the past. Our findings open an entirely new perspective on the evolution of our planet’s internal dynamics."

Reference

Nils Messling et al., Ru and W isotope systematics in ocean island basalts reveals core leakage, Nature (2025). DOI: 10.1038/s41586-025-09003-0