Humans have long been drawn to gold, be it a store of value or as a display of absolute wealth. For the romantic, a subconscious connection to its otherworldly origins while for the merchant, the ultimate medium of exchange.
Today (6 August) is the final day of the Diggers & Dealers Mining Forum held in Australia’s ‘gold capital’ – Kalgoorlie, Western Australia. The Kalgoorlie region has produced more than 60 million ounces of gold since the precious metal was first uncovered in the region, particularly in the Golden Mile.
The Super Pit, one of Australia’s largest open pit gold mines in the Golden Mile, produces around 800,000 ounces of gold per year.
In historical terms a centuries old relationship with no signs of waning and in preceding the human-gold nexus, before the Earth even existed, gold was forged in a cosmic vessel, an extraterrestrial relic destined for the third planet from the sun.
But how did this galactic metal become part of the Earth’s story?
When stars, several times larger than the Earth’s sun, reach the end of their lives, they collapse and explode in a process known as supernova nucleosynthesis.
These newly born atoms of gold are then flown across the universe, scattered around like cosmic confetti. Eventually, some of this golden debris found its way to Earth.
From the Nile River
According to The Planetary Society, there have been many instances of near-Earth objects impacting the planet throughout its history. Asteroid impacts are natural processes that shape the surface of our planet, such as volcanoes – and gold deposits.
As Earth was formed, gold, along with other elements, sank deep into the planet’s core but had risen to the mantle and crashed after asteroids hit the planet.
Researchers believe that the asteroid that brought gold to Earth was during a period known as the Late Heavy Bombardment which is thought to have occurred more than 3 billion years ago.
These asteroids, similar to ending the dinosaur age, had stirred Earth’s mantle and crust, lifting gold from deep underground into more accessible places.
In 5,000 BC, Egyptians found gold in the bed of the Nile River and had used the precious metal for objects of adornment, according to Geoscience Australia. For example, when Egyptian pharaoh King Tutankhamen died, his mummified body was partly covered in gold, which was discovered by archaeologists over 3,000 years later.
And yet, while mined in remote areas of the world and sifted rivers, the greatest trove of gold may not be found on the land where humans stand – but on the seabed.
To ocean floors
Today, gold is found in rock ore all around the world, with China leading global production in 2024 at 380 tonnes, as reported by the ‘authority on gold’ the World Gold Council.
The Perth Mint estimates almost 20 million pounds of gold could be at the bottom of the ocean.
Gold finds its way into the ocean through the natural erosion of rocks on land, carried by rivers and streams into the sea. Millions of years ago, gold particles broke down into tiny pieces and became part of the ocean’s chemistry.
In 1,200 BC, unshorn sheepskin was used to recover gold dust from river sands on the eastern shores of the Black Sea, as reported by the National Mining Association.
Duncan McLeish, a postdoctoral research fellow from McGill’s Department of Earth and Planetary Sciences, says that in a 2021 study, it was discovered that sodium ions in seawater are what cause gold nanoparticles to clump together.
“Acting like the acis in souring milk and eventually forming gold veins,” McLeish says.
According to the research published in Proceedings of the National Academy of Sciences of the Untied States of America, the presence of seawater suggests gold veins could form in the seabed.
The National Oceanic and Atmospheric Administration (NOAA) reveals that one study found there is about one gram of gold for every 100 million metric tons of ocean water in the Atlantic and north Pacific oceans.
Undissolved deposits, too, glint beneath the waves, are trapped in rocks miles below the surface. NOAA says that once humans have reached the ocean floor, deposits are encased in rock that has to be mined, which can be extremely difficult.
To deep sea mining
With only about 20% of the Earth’s ocean actually being explored, leaving a significant 80% largely known, it is plausible to say there would be an immense amount of resources, including gold, down in the bottom of the ocean.
According to Australasian Historical Archaeology, in 1866, scientists had suggested that the ocean may contain more than 250 million times more gold than the total present wealth of mankind in the precious metal.
The earliest attempts to measure the amount of gold in seawater can be traced back to Edward Sonstadt, who reported his results in 1872.
Sonstadt experimented with samples of seawater from the coast of Isle of Man – in the Irish Sea between England and Ireland – and found that it contained gold. He suggested that one of his methods might be practically applied to the exploitation of the gold in seawater which might be received at high-water in large tanks and emptied at low water.
Meanwhile after World War One, German chemist Fritz Haber secretly attempted to recover gold from seawater to help pay off war reparations Germany owed. Haber estimated that 65 milligrams of gold could be extracted per metric ton of seawater.
However, this was not achieved as he had discovered his initial calculations were off by 1,000%.
In 2018, chemists in Switzerland identified a new gold-grabbing material, which reported that a molecular sponge – a polymer filled with pores that increases its surface area – attracts between 90-99% of the gold ions in water and can reduce them to shiny nuggets within mere minutes.
As Mining.com.au reported, more researchers are beginning to further develop tools and frameworks designed to support environmental decision-making around potential deep-sea mining activities.
Deep-sea mining refers to the process of extracting mineral deposits from the ocean floor, typically at depths greater than 200m.
A project led by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) represents the first time that ecosystem-based management (EBM) principles have been applied so comprehensively to the deep sea.
Although there is no cost-effective way to mine gold in the ocean as of yet, it was estimated that the amount of gold in the ocean would be worth roughly US$771 trillion, as of 2017, according to Forbes.
From exploding stars to the ocean floor, gold’s journey is nothing short of a cosmic verse.
Although the gold hidden beneath the sea may never be mined, the value of gold might not just be its extraction, but rather its story on where it has come from and how far it has gone.
Write to Aaliyah Rogan at Mining.com.au
Images: Mining.com.au, Britannica, Forbes, & The Metals Company
