Did you know that gold is extraterrestrial? Instead of arising from our planet's rocky crust, it was actually cooked up in space and is present on Earth because of cataclysmic stellar explosions called supernovae. CERN Scientist David Lunney outlines the incredible journey of gold from space to Earth.
Gold is naturally occurring. When heated currents of fluid circulate under the Earth through rocks, it melts and picks up gold and other metals. Chemical differences in the fluids cause them to separate to a certain extent, creating concentrations in the form of lode deposits.
All of the gold found on Earth came from the debris of dead stars. As the Earth formed, heavy elements such as iron and gold sank toward the planet's core. If no other event had occurred, there would be no gold in the Earth's crust. But, around 4 billion years ago, Earth was bombarded by asteroid impacts.
Gold is thought to have been produced in supernova nucleosynthesis, and from the collision of neutron stars, and to have been present in the dust from which the Solar System formed.
Stars need immense heat and pressure to produce heavier elements like gold. This is the kind of pressure that forms when neutron stars collide, which rarely happens. Because these collisions don't occur as often as other cosmic events, and because they don't always produce gold, gold is also scarce in space.
We all know gold is mined from the ground. But, have you ever wondered how it got there? Surprisingly, gold is most likely from outer space – formed in the hearts of dying stars and propelled across the galaxy by supernova explosions before crashing into primordial Earth almost 4 billion years ago.
Finally, scientists know how the universe makes gold. Using our most advanced telescopes and detectors, we've seen it created in the cosmic fire of the two colliding stars first detected by LIGO via the gravitational wave they emitted.
In Australia this concentration of gold took place in the Earth hundreds of millions of years ago in the eastern states, and thousands of millions of years ago in Western Australia. As well as gold, the fluids can carry other dissolved minerals, such as quartz. This is why gold is often found with quartz.
Gold is primarily found as the pure, native metal. Sylvanite and calaverite are gold-bearing minerals. Gold is usually found embedded in quartz veins, or placer stream gravel. It is mined in South Africa, the USA (Nevada, Alaska), Russia, Australia and Canada.
Hundreds of thousands of "diggers" from other parts of Australia, Great Britain, Poland, Germany, and even California sought their fortunes and redefined Australia's national identity. On February 12, 1851, a prospector discovered flecks of gold in a waterhole near Bathurst, New South Wales (NSW), Australia.
Unlike most rocky, icy asteroids, the Psyche asteroid—located between Mars and Jupiter—contains a motherlode of metal, including gold, iron, and nickel.
The Earth's core is believed to contain around 1.6 quadrillion tons of gold, which is about 16 times more than the total amount of gold mined in human history.
The best estimates currently available suggest that around 208,874 tonnes of gold has been mined throughout history, of which around two-thirds has been mined since 1950. And since gold is virtually indestructible, this means that almost all of this metal is still around in one form or another.
Some of the veins produce up to one quarter of an ounce of gold per ton of rock. What makes Dahlonega gold so different from other gold found around the world is the purity. Dahlonega has the purest gold in the world, which is 98.7 percent pure.
Victoria's gold-bearing rocks are sandstones, siltstones and mudstones, deposited in deep marine conditions some 400 million years ago. Today they form a bedrock spine that runs east to west through Victoria, with the Great Divide running along the crest of Victoria's Western and Eastern Uplands.
There are currently 66 operating gold mines in Australia including 14 of the world's largest, 11 of which are in Western Australia making it the country's major gold producer, accounting for almost 70 per cent of Australia's total gold production.
The discovery of gold in the 1850s started a series of rushes that transformed the Australian colonies. The first discoveries of payable gold were at Ophir in New South Wales and then at Ballarat and Bendigo Creek in Victoria.
Considered by most authorities to be the biggest gold nugget ever found, the Welcome Stranger was found at Moliagul, Victoria, Australia, in 1869 by John Deason and Richard Oates. It weighed gross, over 2,520 troy ounces (78 kg; 173 lb) and returned over 2,284 troy ounces (71.0 kg; 156.6 lb) net.
Physical gold, commonly known as gold bullion, is available to buy from registered dealers throughout Australia. However, it is important you do your research and have secure ways to store your bullion. If you want to add exposure to gold in your own portfolio, there are ways to invest without buying gold physically.
Now fully owned by Newmont Goldcorp, the mine reopened in 2009 after a major expansion project that increased the throughput to become Australia's largest gold mine.
There is an asteroid with a metal-composition that lurks around between Mars and Jupiter while orbiting the Sun and it is made up mainly of gold. Named 'Psyche 16', it was first discovered in 1852 by Italian astronomer Annibale de Gasparis and he named the asteroid after the Greek Goddess of Soul 'Psyche'.
Adding or removing protons from a nucleus are types of nuclear reactions. As such, no series of chemical reactions can ever create gold. Chemical reactions change the number and shape of the electrons in an atom but leave the nucleus of the atom unchanged.
So the next time you hold a piece of gold jewelry, look at the metal closely and think about the fact that it is older than life, older than Earth and the sun.
Even along highly active fault lines, it could take 100,000 years or more for minable deposits to form. So yes, gold deposits can replenish themselves. Unfortunately, it won't happen during our lifetime.
Gold helps protect against corrosion from ultraviolet light and x-rays and acts as a reliable and long lasting electrical contact in onboard electronics. Gold is also used by NASA in the construction of spacesuits.