A groundbreaking study from researchers at Germany's University of Göttingen has uncovered tantalizing evidence that the Earth's molten metallic core — long thought to be geochemically sealed off — may, in fact, be slowly "leaking" gold and other precious metals into the rocky mantle and up to the planet’s surface via volcanic activity.
This surprising discovery opens up a fascinating new chapter in our understanding of Earth’s geology, and it may even help explain the origins of some of the precious metals we rely on in jewelry, electronics and clean energy technologies.
The key to the discovery lies in Hawaii’s volcanoes. Scientists analyzed volcanic rocks, including samples from the actively erupting Kilauea volcano, and found something astonishing: an unusually high concentration of a rare deep-Earth isotope of the platinum group metal ruthenium, known as 100Ru. This particular isotope acts like a chemical fingerprint, revealing that the ruthenium in these rocks must have originated not from the Earth’s mantle — as would be expected — but from the core itself, some 3,000 kilometers (about 1,900 miles) below the surface.
Detecting such a faint signal is no easy task. In fact, past attempts had failed to differentiate the tiny isotopic differences between mantle- and core-derived ruthenium. However, new ultra-precise analytical techniques developed by the Göttingen team finally cracked the code. The presence of core-derived 100Ru in Hawaiian lava flows is now taken as direct evidence that material from the Earth’s core is migrating upward through the mantle.
“This is the geochemical equivalent of striking gold,” said Dr. Nils Messling, lead author of the study, published in Nature. “It shows that the Earth’s core is not entirely isolated and that metals from the core, including gold, are being transported up toward the surface.”
While more than 99.999% of Earth’s gold remains locked deep within the core, unreachable by any mining technology, this study suggests that volcanic activity may deliver tiny, but measurable, amounts of these core metals to the surface.
Hawaii, for example, sits atop a deep mantle plume — a jet of superheated rock rising from the boundary between the core and the mantle. These plumes act as natural elevators, bringing up material enriched in precious metals.
Study co-author Matthias Willbold, a professor at the University of Göttingen, added, “This process isn’t just about gold. It’s about understanding the inner workings of our planet. The core and mantle are interacting in ways we never fully appreciated before.”
For jewelry lovers, this research provides a poetic reminder that the treasures we wear may, quite literally, come from the heart of the Earth.
Credit: Illustration by The Jeweler Blog using Microsoft's AI image generator.