Where does gold come from? Part 1
Astronomers now suggest that the heaviest elements such as gold, platinum, and palladium may have been formed in the early universe as a result of neutron star collisions. These neutron-rich explosions caused by the spiraling together of neutron stars were the most powerful explosions in the universe, and probably accounted for the formation of the neutron-rich heavy elements such as gold.
Dr. Stephen Rosswog from the University of Leicester in England described this in an April 5th interview on National Public Radio (U.S.):
“This is a collision of a special kind of stars. They have masses like our sun, approximately, but a diameter of, say, 20 kilometers or something, so it’s superdense. So one teaspoon of material has a weight of billions of tons. When they collide and eject material and this material becomes decompressed, this is just an ideal environment for the formation of these heavy elements.”
All matter on Earth, and the rest of the universe, is the remnants or ashes of these cosmic events. We’ve known for a while that solitary explosions of supernovas were the source of elements such as carbon, and now it seems that the collisions of supernovas are the likely source of gold and the heavy elements of the platinum group.
Where does gold come from? Part 2
Gold was the original recyclable substance. Because it is soft and easy to work with, whatever one makes out of gold, whether jewelry or artwork, gold is always easily repaired, or worked into a new shape entirely. And because of its scarcity, old gold is never thrown away, but instead is always recycled. Today, all the gold in the world would form a cube approximately 50 feet on each side, that would fit easily underneath the Eiffel Tower.
The gold bullion and coins that you see today may be made of newly-mined gold, but they may just as easily contain gold from the past. When Pizarro conquered Peru in 1531, golden treasures to fill a room 17 feet by 22 feet were converted to bullion bars (it took a whole month to melt down the Inca temple ornaments, animal sculptures, goblets, and other treasures) and hauled back to Spain. South America was the most important source of gold for the European money markets for centuries. At that time, a rich person was commonly described as being ‘worth a Peru.’
Much of the gold that we use has a long history. Today’s gold supply, in addition to the 2,400 tons newly mined every year, includes old lost treasures, plunder from ancient tombs, melted coins from antiquity, dowries, tributes, ransoms, and all the gold found, mined, and stolen over the centuries.
Where does gold come from? Part 3
Alluvial or placer gold is gold that is found ‘loose’ on this planet, usually in the form of pieces as fine as flour up to nuggets weighing a few grams or, very rarely, up to a few pounds. This is raw, native gold that was long ago loosened from the ore which once contained it, usually by the action of wind and water. Placer gold has been our traditional source of gold over the millennia. Deep mining, which is responsible for South Africa’s vast gold production today, wasn’t started until the late 1800’s.
Placer gold is often found in streambeds, both flowing and dry. Its rounded shapes are the products of thousands or millions of years of weathering. Most placer gold as it comes from the ground is 70% to 95% pure gold, depending on where its found.
Here in Arizona, quite a bit of alluvial gold has been mined over the years. The earliest Anglo settlements in Arizona were established in the 1860’s near the gold diggings around what is now Prescott. Gold and copper mining were the impetus to early settlers in Arizona, bringing first the Spanish and then the English, Chinese, and various European expatriates, many of whom were fresh off a stint in the California gold fields in the early 1850’s.
Today in Arizona there are still some profitable smaller-size gold mines, and gold and silver are by-products of this state’s huge copper pit-mining operations. Many commercial gravel dredge operations here yield their owners a bit of gold. Most sunny weekends bring out the gold panners, sluice operators, and treasure hunters wielding metal detectors, each out in Arizona’s vast remote areas of desert and forest, looking to add a bit of color to his or her poke.
It was in the early 1990’s that I got a call at our office here about what was described as a 2-pound chunk of pure gold. A young man had inherited it from his grandfather, who had taken it out of Big Bug Creek up around Prescott during the Depression. Now that young man was looking to sell it, and had been referred to us.
Now I must admit to a certain amount of skepticism. Not about the gold itself - I knew that a lot of gold had come out of Big Bug over the years, and dredging operations and weekenders still worked it today. No, the claim as to the size and purity were what gave me pause.
I told him to bring it down to us and we’d check it out.
In about two hours a tall string bean of a young man in a cowboy hat, jeans, and boots arrived carrying a brown grocery bag. He took out of the bag the damndest thing I’d every seen. It was a crescent-shape lump of native gold, weighing more than two pounds. It had a rich gold color, and it was shaped like this: imagine a cast-iron skillet, tilted to the side ever so slightly, molten gold poured into the skillet, forming the shape of a crescent moon.
Judging from the shape of it, there was no other way it could have been formed. The bottom and sides of this piece of raw gold had the mottled texture of a cast-iron skillet, and on the smooth top of the piece you could see tiny rocks as often occur with placer gold. Probably a mixture of nuggets and flour gold were place in the skillet and heated until the gold melted and then cooled and hardened.
He told us that his grandfather, who handed the gold down to him, had promised him it was pure gold. I gave him an 80% cash advance against the assay of the gold value, and I tried to be diplomatic about his belief that this was ‘pure gold.’ I explained to him that in our experience, the assay on unrefined gold from Big Bug Creek was probably going to show it to be 80% to 90% pure.
So we sent this crescent-shaped mass of gold out of the frying pan and into the fire of the refinery.
A week later, the assay results came back at 99+% pure gold.