Scientists have finally solved a long-standing mystery about the geologic process behind large gold nuggets found within quartz rock. Most gold is mined from quartz ore deposits, but the exact process of how large pieces of gold form within quartz has baffled experts for years. A new study published in Nature Geoscience suggests an unexpected answer: earthquakes and the electrical properties of quartz.
Gold has always been a hot commodity. While much of the world’s gold is mined from natural veins of quartz, the geologic process that puts gold nuggets there was unknown. The study reveals that these nuggets owe their existence to the strange electrical properties of quartz.
When quartz is stressed, it generates electricity, which drags gold particles out of fluid in the Earth’s crust. These particles crystallize into grains of gold and, over time, with enough electrical stimulation, these grains form into nuggets. “If you shake quartz, it makes electricity.
If you make electricity, gold comes out,” explains Voisey, a geologist at Monash University in Australia and the lead author of the study.
Earthquakes and gold nugget formation
Earthquakes are identified as the natural source of this shaking, causing the generation of electric fields within quartz veins, thus enabling the formation of gold nuggets.
Quartz veins, which host a disproportionate number of gold nuggets, are found in parts of the Earth’s crust that have undergone significant stress and strain from geological events like mountain formation. Earthquakes cause ruptures within these veins, allowing hot geologic fluids containing gold particles to migrate, cool, and form gold-rich quartz veins. The study’s experiments demonstrated that shaking quartz in gold-bearing solutions results in the formation of gold particles.
When a pre-existing nugget of gold is present, additional gold particles are drawn to it, causing the nugget to grow. This suggests that gold nuggets are not formed in a single event but through multiple earthquake events, gradually accumulating more gold over time. The concept that electrical fields, generated by earthquakes within quartz veins, assist in the formation of gold nuggets is both elegant and novel, making sense of how large concentrations of gold form in such specific locations.
This research not only solves a geological mystery but also illustrates the intricate and often surprising ways natural processes create valuable resources. “This study shows that although nature is capable of acts of magic, it just takes the right team, and the right experiment, to reveal how the trick is performed,” says Voisey. The revelation is a breakthrough in understanding the formation of gold nuggets, providing a clearer picture of geological history and the natural processes shaping our planet.
April Isaacs is a news contributor for DevX.com She is long-term, self-proclaimed nerd. She loves all things tech and computers and still has her first Dreamcast system. It is lovingly named Joni, after Joni Mitchell.
