Produced by: Manoj Kumar
Gold’s journey from Earth’s mantle to its surface relies on sulfur, which bonds with gold and enables its transport through volcanic activity, defying its natural sequestered state.
Subduction zones, where tectonic plates collide, create volcanic chains like the Pacific Ring of Fire, where gold deposits rise through magma formed in these high-pressure zones.
Scientists agree sulfur is the transport agent for gold. What’s debated is whether trisulfur or bisulfide plays the critical role in creating soluble gold complexes.
Deng-Yang He’s team, through thermodynamic modeling, identified trisulfur as the key to gold’s journey. Their model predicts highly efficient gold extraction from Earth’s mantle.
Farsang and Zajacz’s experiments challenge trisulfur’s supremacy, revealing bisulfide as a viable agent even at high magmatic temperatures, previously thought impossible.
The Geneva team’s laser techniques debunk prior studies that overestimated sulfur radicals, calling into question widely accepted data from a 2011 landmark paper.
The formula Au(HS)S3–, identified by He’s team, highlights trisulfur’s potential to transport gold in concentrations far exceeding mantle averages, reshaping mineralogy insights.
Sulfur’s behavior under extreme conditions—whether trisulfur or bisulfide dominates—offers clues to unlocking how Earth’s crust gained its richest gold deposits.
The rivalry between trisulfur and bisulfide continues as researchers refine methods and challenge each other’s findings, pushing the boundaries of geochemistry.