How gold is created: from cosmic origins to extraction on Earth

Gold has captured the imagination for thousands of years. It is rare, durable, and globally recognized as a store of value. But how is gold actually created? And is it true what you sometimes hear: “does gold come from space?”

In this article, you will receive a complete, scientifically-supported overview: from the formation of gold in the universe to the geological processes that concentrate gold on Earth, and of course, how gold is ultimately extracted.

Where does gold come from: the cosmic origin of gold

To understand how gold is created, we must look beyond the Earth. The element gold was not formed in the Earth's crust, nor during normal stellar processes. The origin of gold lies in the universe, during exceptional events where extreme natural forces are released.

Stars as building blocks of elements

Stars play a central role in the creation of almost all chemical elements. In their cores, lighter elements are converted into heavier ones, such as carbon, oxygen, and iron, through nuclear fusion. This process generates energy and sustains a star.

However, this mechanism stops at iron. Forming elements heavier than iron consumes energy instead of producing it. Therefore, such heavy elements, including gold, require much more extreme conditions than those present in an ordinary star.

The r-process: the key to gold formation

Gold is created via the so-called r-process (rapid neutron capture process). In this process, atomic nuclei capture large amounts of neutrons in a short period. This allows for the creation of extremely heavy and unstable atomic nuclei, which subsequently decay into stable elements such as gold, platinum, and uranium.

Two conditions are crucial for this r-process:

• a massive amount of free neutrons
• extremely high energy and pressure

These conditions occur almost nowhere, except during rare cosmic catastrophes.

Neutron star collisions

The most important known source of gold formation is collisions between neutron stars. Neutron stars are the extremely compact remnants of massive stars that exploded as supernovae. They consist almost entirely of neutrons and have an unprecedentedly high density.

When two neutron stars collide, a so-called kilonova occurs. During such an event, enormous amounts of neutron-rich material are hurled into space. In this environment, the r-process can take place on a large scale, forming significant amounts of gold in a short period.

Observations of gravitational waves and light signals since 2017 (GW170817) have strongly confirmed this theory. For the first time, scientists could directly measure that heavy elements, including gold, are created during such collisions.

Magnetars: an additional source

Recent NASA research indicates that magnetars, neutron stars with extremely strong magnetic fields, may also contribute to the formation of heavy elements. During rare, highly powerful magnetic outbursts, neutron-rich conditions can also arise in which the r-process occurs.

While neutron star collisions likely provide the largest contribution, magnetars help explain how heavy elements could have been present relatively early in the history of the universe.

Dissemination through the universe

The gold created during these cosmic events does not stay in one place. It is dispersed throughout the universe as part of dust and debris. This material mixes with gas clouds from which new stars and planets are later formed.

When our solar system was formed approximately 4.6 billion years ago, this gold was part of the primordial material from which the Earth was also formed. The gold we know today is therefore billions of years older than our planet.

So, does gold come from space?

Yes, in origin, gold comes from space. The element gold is not created on Earth but is formed during extremely violent cosmic events. Scientists now know that gold is created when heavy stellar remnants, such as neutron stars, collide with each other.

During such a collision, enormous amounts of energy and free neutrons are released. This allows heavy elements, including gold, to be built up at the atomic level.

When the Earth was formed, this gold was incorporated into its structure. Over the course of millions of years, it has been moved and concentrated by natural processes, allowing it to be mined in specific locations today.

The gold we mine now is not newly formed material, but a small, accessible part of a much larger cosmic legacy.

Gold did not originate on Earth itself, but in the universe during cosmic events.

How does gold end up on Earth?

The fact that gold has its origin outside of Earth does not mean it is automatically available in extractable form. Between cosmic formation and human extraction lie billions of years of natural processes. These proceed roughly in two phases: incorporation into the young Earth and geological concentration.

1. Gold as a building block of the young Earth

When the solar system was formed about 4.6 billion years ago, it consisted of gas, dust, and heavy elements that had been formed earlier in the universe. Gold was part of this primordial material.

• During the formation of the Earth, gold was incorporated into the planetary material
• Due to the immense heat, the young Earth was largely molten
• A large portion of the gold sank to the core

👉 The gold we can mine today is therefore only a small remnant that remained in the Earth's crust.

2. Geology makes gold findable

Gold usually occurs in the Earth's crust in very low concentrations. It is only through geological processes that it is brought together locally into extractable deposits:

Key processes:

1. Hydrothermal fluids: Hot water with dissolved minerals flows through cracks in rock. Upon cooling, gold precipitates, often in quartz veins.
2. Weathering and erosion: Gold is chemically stable. When rock breaks down, gold remains behind and is moved by water.
3. Alluvial deposits: Due to its high density, gold collects in riverbeds and sediment layers.

Why is gold so scarce?

The scarcity of gold is no coincidence. It is the result of a combination of cosmic rarity and earthly limitations. This makes physical gold fundamentally different from many other metals.

1. Gold is only created during exceptional cosmic events

Gold is among the heaviest natural elements. The conditions required to form it rarely occur in the universe. Gold is only created at all during extremely high-energy processes. As a result, gold is scarce from the moment of its creation, even before it ever reaches a planet.

➡️ In other words: gold is not rare because it is "running out," but because it was never formed in abundance.

2. Most gold is inaccessible

When the Earth was formed, it was largely molten. Heavy metals, including gold, sank to the core. This means that:

• the vast majority of all earthly gold is locked deep within the Earth
• only a small portion is available in the Earth's crust
• furthermore, this portion is highly dispersed

The gold we can mine is thus only a fraction of the total.

3. Findable gold deposits are rare

Even in the Earth's crust, gold usually occurs in microscopic quantities. Extractable deposits only arise where geological processes have concentrated the gold.

Think of:

• quartz veins
• specific rock layers
• river deposits

These conditions only come together in a few places at once.

4. Gold cannot be artificially replenished

Unlike some raw materials:

• gold cannot be "grown"
• it cannot be synthetically produced on a significant scale
• it does not disappear through corrosion, but nothing is added either

The total amount of extractable gold therefore grows very slowly.

How is gold extracted?

Gold mining is a technical and lengthy process. It does not start in the mine, but long before: with the finding of economically viable gold deposits. Depending on where and how the gold occurs, different methods are applied. Nevertheless, gold mining almost always follows the same main lines.

1. Locating gold (exploration)

Before a single gram of gold is mined, geologists investigate where gold may have concentrated.

This is done using:

• geological maps and soil surveys
• drilling to determine gold content
• geochemical and geophysical measurements

A mine is only developed if the gold content is high enough and extraction is economically feasible.

2. Extracting gold from the ground

There are two main forms of gold mining:

Alluvial mining (placer gold):

In this method, gold is extracted from sand and gravel in riverbeds or old sediment layers.

Characteristics:

• gold has already broken loose from the rock
• extraction is done using water and gravity
• relatively simple technology

Due to its high specific gravity, gold sinks to the bottom and can be separated from lighter material.

Primary extraction (hard-rock mining):

In primary deposits, gold is trapped in rock. This requires larger-scale mining:

• open-pit mines or underground tunnels
• crushing and grinding of rock
• transport of ore to processing plants

3. Separating and concentrating gold

After mining, the gold must be removed from the ore. This happens in several steps:

• reduction of the rock
• concentration via gravity or flotation
• chemical extraction, often using cyanide (cyanidation)

In the cyanide process, gold is dissolved and later recovered from the solution. Modern mining is subject to strict environmental and safety standards.

4. Refining into pure gold

The raw gold is then refined to a very high purity, usually 99.9% or higher. Only then is it suitable for:

• gold bars
• gold coins
• industrial applications

Gold mined on Earth is billions of years old and is naturally limited in availability.

Where is gold mined?

Gold is always found in areas with fault lines in the Earth's crust. Gold can actually precipitate during earthquakes. However, this does not happen in every area with earthquakes because gold is not evenly distributed across the Earth's crust, meaning gold is almost non-existent in some places.

It occurs most frequently in areas located on land and near former mountain ranges. The most famous gold mines are located in the United States, South Africa, Indonesia, Australia, and Peru.

Conclusion: this is how gold came to Earth

Gold is not created on Earth but originates in rare and extreme cosmic events. Only during the formation of the Earth did this gold become part of our planet, with only a small portion remaining in the Earth's crust. Through millions of years of geological processes, that gold has been locally concentrated and eventually became extractable.

This combination of cosmic rarity, limited availability, and complex extraction explains why gold is scarce. It is precisely this natural scarcity that has formed the basis for the special value and lasting appeal of gold for centuries.