Earth's core holds 99.999% of the planet's gold

A study published in the journal ‘Nature’ by researchers from the University of Göttingen reveals that nearly 99.999 percent of Earth's gold is trapped approximately 3,000 kilometers below the surface within the planet's core. This occurred during a process known as core-mantle differentiation over 4.5 billion years ago, when heavy elements like gold, platinum, and ruthenium sank toward the center of the planet.

While the vast majority of gold remains inaccessible, scientists have found chemical evidence that material from the deep mantle is slowly migrating toward the surface. By analyzing basaltic rocks from the active lava lake of the Kilauea volcano in Hawaii, a research team led by Nils Mesling and Matthias Willbold detected a specific isotopic signature of ruthenium-100 and unusual tungsten isotope values.

These chemical fingerprints indicate that the material originates from the boundary between the mantle and the core. The researchers noted that while the core's cooling process creates oxide layers rich in ruthenium and tungsten at its outer boundary, these layers do not contain pure gold or platinum, explaining why volcanic eruptions do not yield precious metal nuggets despite the chemical traces.