How Precious Metals Are Leaking From Earth’s Core
Contrary to popular belief, the Earth is not very rich in metals, including rare and precious metals like gold. The problem is that most of the heavier elements sank to the core during the planet’s formation from an agglomeration of asteroids.
As a result, more than 99.999% of Earth’s stores of gold and other precious metals lie buried under 3,000 km of solid rock.
For a long time, it was assumed that these minerals would stay locked into the Earth’s core until the end of time. However, a new study reveals this might not be the case.
By improving the detection method of another element, ruthenium, researchers of the Georg-August-Universität Göttingen (Germany), University of Bristol (UK), University of Edinburgh (UK), and Colgate University, (USA) have proven that material from the Earth’s core can leak into the mantle and up to the planet’s surface.
“When the first results came in, we realized that we had literally struck gold! Our data confirmed that material from the core, including gold and other precious metals, is leaking into the Earth’s mantle above.”
Dr Nils Messling – Researcher at Göttingen University
They published their discovery in the prestigious review Nature1, under the title “Ru and W isotope systematics in ocean island basalts reveals core leakage”.
How Earth’s Core and Mantle Formed
During the early days of the solar system, dust particles aggregated into countless asteroids, which themselves aggregated into bigger and bigger elements, forming the protoplanets that would later on form the 4 rocky planets (Mercury, Venus, Earth, and Mars).
During this process, the planets were mostly melted magma, due to the intense heat generated by the collisions. Progressively, the heavier elements fell to the core due to gravity, differentiating from the mantle. Later on, the planet kept receiving more material from space, forming more of the mantle.
Source: SG Online
Crucially for the study discussed here, the mantle displayed a very different composition for some isotopes of some elements, including ruthenium, due to this later formation using different materials.
How Scientists Trace Core Elements to the Surface
Ruthenium: The Isotope That Tells a Core Story
As ruthenium is mostly locked in the core, and with ruthenium-100 more abundant in the core, detection of this isotope can prove that metal came from the core instead of the mantle, normally the source of most surface rocks due to volcanic activities.
A new, more precise method to measure the presence of ruthenium-100 has previously been developed at the University of Göttingen, allowing for this study.
This was confirmed when studying very ancient rock, like samples from Greenland as old as 3.7 billion years, before the definitive separation of core and mantle would change ruthenium-100 composition.
Source: Nature
More interestingly, it appears that at least some volcanic islands display rocks with a strongly skewed ruthenium-100 ratio toward rocks having received core additions.
This is not true for all volcanic islands, as, for example, samples from La Reunion or the Galapagos Islands are not different from rocks originating only from the mantle.
“We can now also prove that huge volumes of super-heated mantle material – several hundreds of quadrillion metric tonnes of rock – originate at the core-mantle boundary and rise to the Earth’s surface to form ocean islands like Hawaii.”
Professor Matthias Willbold – Professor at Göttingen University
Why Tungsten Supports the Core-Leakage Hypothesis
Tungsten, or wolfram (hence the W sign for this element), is another heavy metal mostly located in the Earth’s core.
Here the scientists studied a metric called μ182-W (parts-per-million (ppm) deviation of 182W/184W from terrestrial standard. But measuring which type of isotope of tungsten is present in the sample, clarifies how the minerals from the core mixed with the magma of the mantle to form the volcanic rocks of Hawaii islands.
This isotope ratio clearly shows that the tungsten detected is not from the decomposition of hafnium, another potential source of tungsten in the mantle.
New Theory Explains How Core Elements Reach the Surface
From the variation of tungsten composition, the scientists deduced a previously unknown mechanism: around the Earth’s core formed an oxygen-rich outer core domain.
Over time, the crystallization of metal-rich oxides through secular core cooling locks in some of the tungsten.
“Whether these processes that we observe today have also been operating in the past remains to be proven. Our findings open up an entirely new perspective on the evolution of the inner dynamics of our home planet.”
Dr Nils Messling – Researcher at Göttingen University
Why This Discovery Matters for Mining and Industry
This is not just an academic pursuit. Many of the elements present in the core are either of very high value, like gold, or very useful in modern society, like, for example, tungsten, an ultra-hard metal used in semiconductors, industrial tools, aerospace, weapons, and engines.
Discovering that some of these metals come from the Earth’s core radically changes the perspective of geologists on how such deposits form, and how the deepest layers of our planet can interact with the surface.
In turn, this could change the way exploration for these rare elements is done by mining companies. For example, analyzing the ruthenium content of the rocks of a region could reveal it contains Earth’s core intrusion, radically increasing the chance of finding more heavy elements in the same place.
Final Thoughts: Why Core-Mantle Science Matters
This sort of study might sound a little abstract and only of scientific interest at first. However, understanding how our planet formed and how some parts of the Earth’s core can resurface can help us find more of these important metals.
This could also change how we understand the geology of other planets, especially Mars and Venus, which are somewhat similar to Earth. If a resurgence of core elements is possible on Earth, it could be as well on other planets.
As we are looking at potential Martian colonies in the upcoming decades, it could be of great interest to know if some of the planet’s core metallic resources could be a lot easier to access than previously thought, especially with Mars having the largest volcanoes of the solar system, with a profile similar to the volcanoes of Hawaii.
Investing In Earth Core Elements
Almonty Industries
Among Earth’s core elements, one of the most useful and least known to investors is tungsten. This very resistant metal is important for a wide array of high-tech industries. It is also currently produced almost exclusively in China and Russia.
We covered in more detail the investment case for tungsten in detail in the October 2024 report “Tungsten – The Secret High-Tech Metal”.
Almonty Industries is a tungsten miner that is currently mostly produced from a mine in Portugal, in operation for the last 125 years.
The company has been working on expanding the Portuguese mine and owns undeveloped deposits in Spain.
Source: Almonty
The company’s most important project is the ongoing development of a new mine in Sangdong, South Korea. The mine contains more inferred resources than all of its other deposits combined.
Source: Almonty
As one of the only active and producing tungsten miners in Western countries, Almonty is a key strategic supplier for the defense industry. So it is an important company for reducing dependence on Chinese supply.
The Sangdong mine’s location makes it a perfect supplier to the defense industry, with South Korea a new giant in mass production of “low tech” military gear like tanks, artillery, and ammunition (compared to less tungsten-demanding fighter jets, aircraft carriers, etc.).
While China prepares to open a huge tungsten mine in Kazakhstan, Almonty is poised to “substantially shift the politics involved with securing tungsten” when the Almonty Korea Tungsten Project’s Sangdong mine comes online within a few months. When it begins production, it will be one of the world’s largest tungsten mines, accounting for 30% of the non-Chinese supply.
Lewis Black, director, president, and CEO of Almonty Industries
Almonty should start producing tungsten from the Korean mine in early to mid-2025.
Because of its strategic position as essentially the sole large supplier in the West, Almonty was offered a guaranteed price by Plansee. Plansee is a high-performance metal manufacturer and one of Almonty’s larger clients, as well as the owner of 15% of the company.
The minimum guaranteed price was $235/MTU (metric ton unit), with no upper threshold. As Sangdong Mine is aiming for cash costs of $110/mtu, this should virtually ensure a high profit margin for the project.
With a luckily almost perfect timing between the upcoming opening of Sangdong and a new trade war between Trump’s America and China, the stock price has reacted strongly and rose by 40% in just 2 days following the announcement of tungsten export restriction from China.
Studies Referenced:
1. Messling, N., Willbold, M., Kallas, L. et al. Ru and W isotope systematics in ocean island basalts reveals core leakage. Nature (2025). https://doi.org/10.1038/s41586-025-09003-0