Scientists unveil the reasons behind gold's detectability

In a groundbreaking study, scientists have uncovered the atomic-scale attraction between gold and arsenic-rich minerals, providing insights into the formation of most gold deposits and potentially paving the way for more efficient gold mining and processing.

The research, conducted at the European Synchrotron (ESRF) in Grenoble, France, reveals that when a mineral is enriched with arsenic, gold can enter the mineral's structural sites by directly binding to arsenic. This association has long been known in the mining industry, with gold often occurring in association with arsenic because it can be chemically bonded or physically included in arsenic-containing minerals like arsenopyrite (FeAsS).

This knowledge, dating back to historic mining regions in Europe and worldwide, has been instrumental in locating new gold deposits. Geologists target arsenic mineralization zones, as they often indicate the presence of gold hidden within or near the arsenic-bearing minerals. However, the new findings help to explain why this association occurs.

Dr. Jeffrey Hedenquist, a geologist from the University of Ottawa, commented on the association between gold and arsenic-rich minerals. He suggested that geologists and prospectors have long known about this association, but the new findings provide a more comprehensive understanding of the process.

Unfortunately, the environmental consequences of arsenic pollution from gold mining continue to persist in certain regions. The Salsigne mine near Carcassonne, once one of Western Europe's largest gold mines and the world's largest arsenic producer, closed in 2004. However, the environmental consequences of arsenic pollution still persist in the region.

The findings may provide insights into preventing health problems associated with the noxious link between arsenic and gold. Additionally, they may make it easier to find new sources of gold and other precious metals that bind to arsenic-containing iron sulfides. Gold becomes invisible to the naked eye when chemically bound in these minerals, making it challenging to locate and extract.

However, the new findings may open the door to controlling the chemical reactions and potentially improving gold processing to recover more gold. This could lead to more efficient mining operations and reduced environmental impact.

In conclusion, the study sheds light on the long-standing association between gold and arsenic, offering a deeper understanding of their atomic-scale attraction. This knowledge could revolutionise the gold mining industry, making it more sustainable and efficient.