Gold has been collected and studied since the dawn of time. A marvel of nature, the element is ubiquitous in cultures around the world, appearing in ancient folklore, modern films and everything in between. Yet there’s still plenty about gold that scientists don’t fully understand, and new discoveries about its origins are being made all the time.
Gold nuggets, often found tucked inside quartz veins that are embedded in rocks, have been prized for their rarity and beauty for centuries. We know that a neutron star collision gave our planet its gold in the first place, but exactly how large accumulations (pebble to fist-sized chunks) of the beloved metal are formed has been somewhat of a mystery until recently.
Where Are Gold Nuggets Found?
Many of the earliest gold discoveries took place along riverbeds. When James Marshall noticed shiny flakes along the American River in 1848, he sparked one of the largest gold rushes in history. But most of the Earth’s gold, even the pieces that end up in rivers, comes from inside rocks. Heavier elements like gold naturally accumulate in rivers as they’re eroded from surrounding rocks and transported by flowing water. Quartz veins are the most common and well-known source of gold, but gold can also be found in many other types of rocks and geological settings.
Quartz is a common mineral that’s composed of silicon dioxide. A quartz vein is essentially a crack in a rock that has been filled with crystallized quartz. Veins are formed when mineral-containing fluids flow through the cracks and deposit quartz over time. Up to 75% of all the gold ever mined is from quartz vein deposits!
Gold Nugget Formation: Connecting the Dots
There is an explanation, albeit incomplete, for gold nugget formation that’s widely accepted among scientists: gold precipitates from hydrothermal fluids that flow through cracks in the Earth’s crust caused by earthquakes. As the fluids cool or undergo chemical changes, the gold seeps out and gets trapped inside quartz veins.
But this explanation doesn’tfully explain the formation of large gold nuggets, because the concentration of gold in hydrothermal fluids is very low. Under the conditions of normal particle concentration, it would take about 5 Olympic-sized pools of fluid to form a large gold nugget (weighing about 1 kilogram). It’d be almost impossible for this much fluid to seep into quartz veins without another factor at play.
A group of Australian scientists at Monash University set out to find the missing link, and they had a hunch that electricity was involved. They conducted an experiment replicating the conditions that quartz and gold-containing fluids may experience during an earthquake, and the results were remarkable. The study was published in Nature Geoscience this past Fall.
Earthquakes, Quartz and Gold: A Power Trifecta
The Monash University team’s theory goes as follows:
- Quartz is a piezoelectric mineral. This means that it can create an electric charge when it’s exposed to mechanical stress. (This characteristic makes quartz valuable in watches and electronics!)
- Electricity can also cause gold ions in a fluid to gain electrons and form solid gold.
- Then, the solid gold acts as an electrical conductor in the quartz’s electric field, strengthening the overall electrical charge. This causes more gold ions in the solution to concentrate in the same place and ultimately clump together, forming a gold nugget.
Testing the Earthquake Theory
To test their hypothesis, the team submerged quartz crystals in a solution containing tiny, free-floating gold particles. Then they quickly squeezed and released the quartz crystals repeatedly using a motor, mimicking the frequency of seismic waves caused by earthquakes. They found that even modest stress on the quartz led to gold accumulation on the crystal surfaces!
These results are exciting, and the next step is to observe this process happening in nature. While the study provides a great explanation for nugget formation, it’s still possible that the piezoelectric effect is only one of the reasons that gold nuggets form, and other explanations are still waiting to be uncovered. Only time will tell!
2024: An Exciting Year for Gold
The past year has been very exciting for gold in many ways. Not only did we learn more about gold nuggets, but one of the world’s largest and most lucrative gold deposits was discovered in central China. And to top it all off, the market price of gold hit several all-time record highs, surpassing $2,777 per ounce at the end of October. Both scientists and investors with a passion for gold had plenty to celebrate.
Preserving Precious Metals
Gold is a rare and valuable natural resource, and while there’s still much to learn about it, one fact is certain: our planet has a limited supply.
Fortunately, once raw gold has been transformed into items like jewelry or bullion, it can be recycled when those items are no longer in use. Gold, along with other precious metals, is a prime candidate for recycling – not just once or twice, but infinitely. Precious metals can be melted down, refined, and repurposed over and over without losing their original quality.
Recycling common gold items like jewelry and dental scrap material is an eco-friendly choice, and it can also be highly profitable – especially with today’s market prices. If you have unwanted precious metal scrap that you’d like to recycle for cash, look no further than Garfield Refining, America’s premier precious metals refinery!
Disclaimer: This blog post is for informational and entertainment purposes only and is not intended to encourage customers to send raw gold, such as nuggets, rocks, or unprocessed materials. Garfield Refining does NOT accept raw gold in any form. We exclusively refine precious metals in the form of scrap material, such as jewelry, dental material, and other similar items. Please review our accepted materials before sending us your shipment.
Garfield Refining has specialized in precious metals refining since 1892. We take pride in providing the highest payouts for your gold, silver, platinum and palladium scrap. If you have precious metal scrap that you’d like to refine, give us a call or start your free shipment today!