All the world's gold comes from outer space, say scientists
Published 08/09/2011 | 05:00
The world's available supply of gold, worn by people as wedding rings and other jewellery, comes from outer space, new research suggests.
Scientists believe they have evidence that the Earth's reserves of precious metals, including gold and platinum, which have underpinned the world's economies for millennia and which are used to make everything from jewellery to computer parts, are the result of meteorite strikes up to 200 million years after the planet was formed.
Analysing four-billion-year-old rocks from Greenland, experts from the University of Bristol believe they have found the "fingerprints" of huge meteorite bombardments which created the deposits that are mined today.
Dr Matthias Willbold, from the university's School of Earth Sciences, said: "Our work shows that most of the precious metals on which our economies and many key industrial processes are based have been added to our planet by lucky coincidence when the Earth was hit by about 20 billion billion tonnes of asteroidal material."
The scientists believe the impacting meteorites were "stirred" into the Earth's mantle by gigantic currents in the molten material.
Subsequently, geological processes formed the continents and concentrated the precious metals (and tungsten) in ore deposits which are mined today.
The scientists plan to work in future on studying how long this process took.