Gold atoms are formed in space. Most are made when rare events such as collisions between neutron stars flood atomic nuclei with neutrons faster than they can decay; a few percent are built slowly inside ageing stars. On Earth gold is only concentrated: hot water dissolves it from rock and deposits it in veins, and erosion washes it into river gravels called placers.

Is gold from Earth or space?

Gold comes from space. Almost all the gold Earth started with sank into the core along with molten iron. Most of the gold near the surface is thought to have arrived on meteorites after the core had formed, and geology then concentrated it into deposits.

Can gold be created naturally?

Yes, in space: most gold, about 94 percent of the solar system's, is made in events violent enough to pack nuclei with neutrons, such as neutron-star collisions, and the rest is built slowly by neutron capture inside ageing stars. No geological process can make gold, because chemistry cannot turn one element into another. Physicists at CERN have made gold from lead, but the Large Hadron Collider's 2015 to 2018 run produced only about 29 picograms, and the gold existed for a tiny fraction of a second.

Can gold be found naturally?

Yes. Gold commonly occurs in its native form, not combined with other elements, which the US Geological Survey gives as one reason it was among the first metals to be mined. It turns up in quartz veins in hard rock and as dust, flakes, grains and nuggets in river gravels, where its weight concentrates it on or near bedrock.

How long does it take the Earth to make gold?

Earth does not make gold; it only concentrates gold that already exists. A 2013 model by Dion Weatherley and Richard Henley suggests that earthquakes of magnitude four and smaller can drop a little gold and quartz in a fault during the quake itself. A fault system can see thousands of small quakes a year, and Weatherley told Scientific American that over hundreds of thousands of years a fault has "the potential to precipitate very large quantities of gold".

How Is Gold Formed? Stars Made It, Then Earth Swallowed It

The astronomers had to wait ten hours for the sun to go down. Gravitational waves from two neutron stars spiralling into each other had reached detectors in the United States and Italy earlier that day, 17 August 2017.

After dark, a UC Santa Cruz team turned the one-metre Swope telescope at Las Campanas Observatory in Chile on the likeliest galaxies in the search area. The ninth field held NGC 4993, a galaxy about 130 million light years away, with a point of light that had not been there four months earlier.

Over the next few days the light turned from blue to red, the colour that theorists at UC Berkeley had predicted for freshly made heavy elements. From that glow, Daniel Kasen and colleagues estimated the collision’s yield at around 200 Earth masses of gold.

How is gold formed?

Gold is formed in space, not in the ground, mostly when rare cataclysms like neutron-star collisions flood atomic nuclei with neutrons faster than they can decay. Almost all Earth’s original gold sank into the core. The gold we mine is thought to have come later on meteorites; hot water and erosion gathered it into quartz veins and river gravels.

Stars cannot fuse their way to gold

The Big Bang left hydrogen, helium and “a scant amount of lithium”, in NASA’s words. Stars forged heavier elements by fusion, but fusion “continues in red supergiants until iron is formed”, says NASA’s guide to the elements, because “iron releases no energy when fused.” That dead end is where the rust on a red barn begins, and gold lies beyond it.

Getting further means adding neutrons. When a nucleus captures one and turns unstable, a decay can convert a neutron into a proton and move the atom one place along the periodic table. Iron has 26 protons and gold has 79.

A 2021 PNAS feature says most gold forms when “a rapid flux of neutrons bombards iron nuclei”, so fast that new neutrons pile in before earlier ones decay. That is the r-process, r for rapid, and it needs neutron densities like those in the debris of a torn-apart neutron star.

The supernova story is out of date

Bullion-dealer websites say gold was formed during supernova explosions billions of years ago. Most researchers long thought so too, the PNAS feature says, but if supernovae make r-process elements at all, only a rare kind does, under 1 percent of them. The Milky Way has about two supernovae a century, and r-process events happen roughly a thousand times less often.

Berkeley News reported in 2017 that, according to co-author Enrico Ramirez-Ruiz, the observations supported the theory that mergers “can account for all the gold in the universe”. Then a 2020 model of the galaxy’s chemical history by Chiaki Kobayashi and colleagues “found enough silver but not enough gold”. The team favoured fast-spinning magnetic supernovae, but the PNAS feature says Kobayashi’s calculations still find nowhere near enough gold.

In 2025 a study led by Anirudh Patel added magnetar giant flares, estimating they supply at least about 1 to 10 percent of the galaxy’s r-process elements. NASA’s write-up says mergers “happen too late in the universe’s history to explain the earliest gold”. Patel says the question is “a fun puzzle that hasn’t actually been solved.”

Almost all of Earth’s own gold is in the core

As the planet formed, molten iron sank to its centre to make the core and “took with it the vast majority of the planet’s precious metals”, says the University of Bristol: enough to cover the entire surface in a layer four metres thick. Liquid iron still flowing in the outer core generates most of Earth’s magnetic field, the field a compass needle lines up with.

About 99% of Earth’s gold lies in the core, under nearly 3,000 km of rock. Geologist Bernard Wood told ABC Science it is “more than 99%”, and W. F. McDonough’s 2003 model of the core puts it at 98%. Every gold ring, coin and circuit board ever made came out of the percent or so outside it.

Losing that much should have left the outer Earth “bereft of bling”, in Bristol’s phrase. Instead the mantle holds precious metals “tens to thousands of times more abundant” than anticipated.

Greenland rocks point to a late meteorite shower

Bristol’s team tested one explanation, a meteorite shower after the core formed, which would leave “a diagnostic mark” on Earth’s tungsten isotopes. In 2011 Matthias Willbold, Tim Elliott and Stephen Moorbath compared modern rocks with Greenland rocks nearly four billion years old, from a patch of mantle that had not yet fully taken in the proposed bombardment.

The old rocks held about 13 parts per million more tungsten-182, relative to other tungsten, than modern ones, a small difference their Nature paper calls “in good agreement” with the meteorite explanation. The team put the delivery at about 20 billion billion tonnes of asteroidal material, more than 200 million years after Earth formed. A much later impact, the one that ended the age of the dinosaurs 66 million years ago, left a crater about 180 kilometres wide, now buried under the Yucatan and traced at the surface by a ring of sinkholes called cenotes.

The core may also be leaking. In 2025 a Goettingen team found a ruthenium signature from the core in Hawaiian lavas, evidence that core material “including gold and other precious metals, is leaking into the Earth’s mantle above.” Some of the gold we rely on, the university says, “may have come from the Earth’s core.”

Earth gathers gold and never makes it

Changing an element means changing its nucleus, and as CERN puts it, “chemical methods are powerless to transmute” lead into gold. Gold is “relatively scarce in the earth”, says the US Geological Survey, but “concentrated by geologic processes” into lodes and placers.

In one hypothesis the USGS calls widely accepted, many lodes form when water, mostly rain, seeps down fractures, is heated by magma, dissolves metals from rock and drops them as veins in cooler rock nearer the surface.

Gold-bearing fluids are dilute, under 1 milligram of gold per kilogram, which makes big nuggets hard to explain. A 2024 Monash University study led by Christopher Voisey looked to quartz, “the only abundant piezoelectric mineral on Earth”. Earthquakes stress a vein’s quartz thousands of times. In lab experiments, that stress made enough voltage to plate dissolved gold out of solution, and existing grains became the focus of growth because gold conducts.

Placers are the work of erosion. Gold is “extremely resistant to weathering”, says the USGS, and once freed it travels downstream as dust, flakes, grains and nuggets. Impure gold is 16 to 18 times as dense as water, against about 2.5 for waste rock, so it often settles on or near bedrock in concentrations called pay streaks.

Four stages, four levels of certainty

Stage	Where	Evidence	How sure
Atoms made	Neutron-star collisions, perhaps rare supernovae and magnetar flares	The 2017 merger’s light	Mergers seen; tally unsolved
First gold sinks	The core, about 99% of it	Bristol 2011; Goettingen 2025	Established; a leak reported in 2025
Mined gold lands	The mantle, by meteorite	Greenland tungsten	Isotope-backed hypothesis
Gold gathered	Quartz veins, river gravels	USGS; Voisey 2024	Veins accepted; quartz voltage new

Astronomers have caught two neutron stars colliding and glowing with fresh heavy elements, and they still cannot account for all the gold in the galaxy. The metal in a riverbed nugget, or in a coin someone once clipped, was made by events they have not finished counting. Strictly FYI.