A recent study suggests that the smallest planet in our solar system might be hiding an enormous deposit of raw diamonds beneath its surface. While this discovery is fascinating for planetary scientists, the prospect of extracting these diamonds remains far out of reach, at least for now.
Mercury: A Diamond Treasure Trove?
At first glance, Mercury, the closest planet to our Sun, doesn’t seem particularly remarkable—especially when compared to its neighbors like Venus, Earth, or Mars. However, NASA’s recent findings reveal that appearances can be deceiving. Data from the MESSENGER probe strongly indicates that Mercury’s mantle could contain a massive layer of raw diamond, potentially more than 15 kilometers thick.
Despite its rather unassuming exterior, Mercury has long intrigued researchers. One of the most notable aspects of the planet is its unique surface composition. MESSENGER’s observations revealed pockets of graphite scattered across the planet’s crust—an unusual occurrence for a celestial body. This discovery led scientists to believe that Mercury was once covered by a vast ocean of magma rich in carbon, which likely had a significant impact on the planet’s internal structure.
Initially, many planetary scientists theorized that Mercury’s mantle might be rich in graphite. However, an international team of Chinese and Belgian researchers now challenges this idea.
A Colossal Diamond Deposit
The team’s hypothesis stems from experiments conducted using an incredibly powerful hydraulic press. By subjecting synthetic silicate material to extreme pressure and temperature conditions—mimicking those found at the boundary between Mercury’s mantle and its enormous core (which is believed to occupy around 60% of the planet’s total volume)—they observed how this material behaved and transformed under such intense conditions.
By combining these experimental results with precise thermodynamic and geophysical simulations, the researchers were able to model Mercury’s internal structure. Their findings suggest that, contrary to previous beliefs, the gradual crystallization of Mercury’s core did not result in a layer of graphite. Instead, the carbon present in the planet’s mantle likely accumulated in the form of raw diamond.
Given that diamond is less dense than the other metals in Mercury’s core, this layer would have floated to the core-mantle boundary (CMB). And we’re not talking about a few isolated gems—this is a vast deposit. According to the researchers, the diamond layer would have been about 1 kilometer thick at the end of the crystallization process and has likely continued to grow since then. Today, it could exceed 15 kilometers in thickness. With these dimensions, the total volume of this diamond layer could be estimated at over 750 million cubic kilometers!
Valuable Insights for Planetary Scientists
The abundance of this material could have significant implications for understanding Mercury’s geology. For example, it might help explain why Mercury has a surprisingly intense magnetic field for a planet of its size. Until now, no one has been able to definitively explain this phenomenon, but the presence of a diamond layer could offer a compelling explanation.
Diamond has a high thermal conductivity, meaning it can efficiently transfer heat. This conductive layer would significantly impact the heat transfer from Mercury’s liquid outer core to its mantle. These heat flows would, in turn, affect the convective movements that generate planetary magnetic fields, potentially increasing the intensity of Mercury’s magnetic field.
These insights could also help scientists better understand the history of other carbon-rich planets.
Can We Extract These Diamonds and Bring Them Back to Earth?
Naturally, one might wonder whether it’s possible to extract these diamonds and bring them back to Earth. Unfortunately, the answer is a resounding “no,” at least for the foreseeable future, and for several reasons.
First, the diamond deposit would be entirely inaccessible. The core-mantle boundary of Mercury is estimated to be more than 400 kilometers deep, far beyond the reach of any current drilling technology. For context, the deepest drill hole on Earth barely exceeds 12 kilometers. Even if we could drill deeper, the extreme temperature and pressure conditions would quickly become unmanageable. To reach such depths, we’d need to discover a new super-material with incredible resistance and develop a highly complex and massive cooling system.
Even if we somehow overcame these enormous engineering challenges, deploying such infrastructure on Mercury would be an entirely different hurdle. To date, no human-made machine has ever landed on Mercury. Moreover, we currently lack the propulsion systems needed to bring even a small probe back to Earth after landing on Mercury. So, it’s unlikely that we’ll be deploying a massive drilling system on Mercury and returning with containers full of diamond ore anytime soon.
Finally, even if we could achieve such a feat, there would likely be no economic incentive to do so. Consider the Mars Sample Return mission, which aims to retrieve samples collected by the Perseverance rover early in the next decade. This mission, with a budget of around $10 billion, is logistically complex—but retrieving a few grams of Martian dust will be child’s play compared to drilling on Mercury. The cost of such a mission would be astronomical. To justify the expense, we’d need to bring back several tons of diamonds at a minimum, which is impossible given the current technological limitations. In any case, synthesizing artificial diamonds or extracting natural ones on Earth would be far more cost-effective. So, don’t expect to see a Mercury diamond on Earth for a very, very long time!
My name is Noah and I’m a dedicated member of the “Jason Deegan” team. With my passion for technology, I strive to bring you the latest and most exciting news in the world of high-tech.