Gold raises questions about its distribution on our planet. Estimates vary, but one thing is certain: gold is far more abundant in Earth's core than in the crust.
According to data compiled by the U.S. Geological Survey and the World Gold Council, between 206,000 and 238,000 tons of gold have been extracted by humans to date. These figures, while impressive, represent only a tiny fraction of the gold present on Earth. The majority of this precious metal is actually located in Earth's core, inaccessible with current technologies.
The remaining exploitable gold reserves are estimated at about 70,550 tons, mainly located in Russia, Australia, and South Africa. However, China stands out as the largest gold producer in 2024. These reserves are only a fraction of potential resources, whose exploitation depends on technological advances and economic conditions.
The concentration of gold in Earth's crust is extremely low, about 4 parts per billion. This means that although the total amount of gold in the crust is estimated at 441 million tons, its extraction is not economically viable in most cases. Gold particles are scattered in rocks and oceans, making their collection difficult.
The origin of Earth's gold dates back to the planet's formation and the intense meteorite bombardment that followed. Most of the gold sank toward the core due to its density, leaving only a small amount accessible in the crust.
How is gold formed in the Universe?
According to established theory, gold is formed during collisions between neutron stars, extremely violent and rare cosmic events. These collisions release colossal energy, allowing the fusion of neutrons into heavy elements like gold.
This process, known as rapid neutron capture nucleosynthesis, is the only one capable of producing elements as heavy as gold. It explains why gold is so rare not only on Earth but also in the Universe in general.
Once formed, gold is scattered in space and can then be incorporated into new planets and stars. This is how gold could reach Earth.