Gold: how we lost 1000 trillion tons of it forever

Gold: how we lost 1000 trillion tons of it forever

We fought wars for it, worshipped gods by it and expressed love with it. The beauty, rarity and properties of gold shaped human history over millennia. But Earth was not always depleted in its precious metal.

In this article, we examine the untold story behind how we lost 99.9% of the planet’s gold. We go one step further to reveal the origin of gold that humanity has been using since its first discovery.   

The big loss

In the early steps of the solar system, Young Earth was a hot and liquid planet of different elements. One of those elements was gold – 1000 trillion tons of it. That quantity is enough to cover the surface of the planet with a 1.5-meter-thick golden layer, according to geologist Bernard Wood.

Another element was iron, which due to its high density it sank to the centre of the planet to form a sphere twice the size of the Moon. The melted, iron core magnetized towards it all the remaining elements that form bonds with it, including gold. 

As Earth cooled down 4 billion years ago, it formed a solid – empty of gold – surface. All the quantity of its gold got trapped 2900km below the surface, a depth impossible to be reached even with today’s technology. The deepest artificial point humanity managed to dig, is the Kola Superdeep Borehole in Russia reaching a depth of 12.3km.  

The human body contains trace amounts of gold

Despite that, gold is the earliest recorded metal used by humans. Evidence of its use was found in caves from the Paleolithic period, 40.000 BC. Nowadays, it is extensively used in jewellery, electronics and medicine. The human body contains 0.2mg of gold.  

If Earth’s gold became unattainable before life began on its surface, where did all the gold that human civilizations have been using originate from?     

Raining gold

The analysis of billion-year-old rocks enriched in gold revealed the answer. Rocky bodies such as those fell on the planet as meteorites at different times between 4.5 billion and 550 million years ago; a cataclysmic rain of rock and… gold. As they hit the planet, they buried in its crust every gram of gold that humanity is related to. 

Twenty million tons of meteoritic gold were diluted in the oceans due to the high temperatures and acidic environment of Young Earth. But it’s concentrated to such a low degree that no profitable method to this day is able to recover it. Every 100 million tons of seawater consists of 1.3g of gold, according to NOAA.

The rest of the gold (less than 1 million tons) that fell from the sky remained in tiny quantities within rocks. From one ton of a gold-enriched rock, we extract 1g on average of the precious metal.       

We are running out of gold

We discovered around 244.000 metric tons of gold up to date, according to the U.S. Geological survey. Only 57.000 tons are left to be exploited until its extraction cost becomes unprofitable. Predictions say that humanity will reach that boundary by 2050. Plans to mine the precious metal from the moon and Psyche asteroid are underway.   

Every piece of golden jewellery we bear is made of an extraterrestrial, meteoritic metal

Sum up

Every piece of gold we bear as rings, bracelets and necklaces is made of an extraterrestrial, meteoritic metal that travelled through space until it fell on our planet. An unreachable ocean of gold is buried 3km under our feet.

As the deposits near the surface will soon become unprofitable, humanity is looking up to the skies for the future of the precious metal.

We are not very far from a space gold rush, but that is for another Unknown Story Behind.     

Some extra 

  • The word “gold” derives from the Old English word “geolu” which means yellow. Its chemical symbol is Au, from the Latin word “Aurum” translated as “shining dawn”   
  • “Welcome stranger” is the biggest, recorded piece of gold ever found. It weighed around 70kg and had a length of 60cm.        
  • It is possible to create gold in a nuclear reactor, but its high production cost makes it unprofitable    
  • The deepest gold mine in the world is located 4km under the ground of South Africa