Gold, especially in nugget form, is highly valued for its rarity, beauty, and malleability. Throughout history, it has symbolized wealth and power, and today, it remains an essential asset in finance, jewelry, and technology.

Deep underground, the fracture boundaries between quartz are key sites where large gold nuggets form. According to the World Gold Council, as much as three-quarters of the gold mined annually, or roughly 1,875 to 2,250 tonnes, comes from quartz underground. This phenomenon has recently gained a plausible explanation.

Scientists have proposed that earthquakes play a crucial role in forming gold nuggets. The intense pressure from seismic activity squeezes quartz, generating electric fields that help gold concentrate in these fractures. However, a longstanding question persists: How do large nuggets, some weighing up to hundreds of kilograms, form when the gold concentration in quartz vein fluids is only about one part per million? To form 10 kg of gold would require the water equivalent of five Olympic swimming pools.

Quartz is unique as the Earth's only abundant piezoelectric material. When compressed, its crystal structure generates an electric voltage—a property used in piezoelectric lighters to create a spark with a button's press.

As publishedin *Nature Geoscience*, researchers explained, "This mechanism can help explain the creation of large nuggets and the commonly observed highly interconnected gold networks within quartz vein fractures." Voisey and his colleagues suggest that the electric fields generated by seismic pressure could extract gold from surrounding solutions, accumulating it on the quartz surface.

Dr. Taija Torvela, a structural geologist at the University of Leeds, noted, "It is true that we’ve been unable to explain why, in some cases, gold becomes extremely concentrated and forms very large nuggets."

Source: https://www.theguardian.com/science/article/2024/sep/02/scientists-find-seismic-role-in-formation-of-large-gold-nuggets