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Iron spins at the Earth's core and flows through our veins. This powerful metal is also a key player in mysteries like the disappearing iron on Earth and the rare variant created by ancient Chinese potters that modern labs cannot replicate.
Iron may seem ordinary, but it appears in astonishing ways—like tiny metallic balls inside birds' heads or molten rivers beneath the Earth's surface. It can even take on strange forms, turning fruit purple or pretending to be platinum.
10. The Secret to Life’s Origins
Oxygen is fundamental to life on Earth, and tracing its origins could unlock the secrets of how life first emerged. A major enigma in this area occurred between 2.5 and 2.4 billion years ago.
Oxygen levels began to rise unexpectedly, without clear cause. The best prospects for finding answers lie in Western Australia, home to the Banded Iron Formations, which are linked to the period when the atmosphere became rich in oxygen.
The iron ore might hold sulfur isotopes, with the chemistry of these particles offering valuable insight. They could serve as a snapshot of oxygen’s earliest evolution. Previous studies have also suggested that the East Pilbara region has a long history of volcanic activity, potentially contributing to the oxygen-rich atmosphere.
Sadly, the isotopes are buried too deep underground for most scientists to access. However, if a mining company were to drill for samples, the cores could provide the full story of how a world devoid of oxygen became increasingly hospitable for life.
9. The Purple Orange
In 2018, a woman from Australia sliced into an orange. Within a few hours, the fruit mysteriously developed purple spots. The odd wedges were quickly sent to a laboratory, along with the knife she used. When the researchers discovered that the woman's husband had sharpened the knife just a day or two before, they also took the steel sharpener for analysis.
It turns out that the pair of tools played a crucial role. Tests on the strange fruit revealed that the purple stains were caused by a reaction between a pigment called anthocyanin and iron.
The anthocyanin pigment is naturally found in oranges, while the iron originated from the freshly sharpened blade. Despite the owner rinsing the knife, microscopic metal particles remained. These particles transferred to the orange during slicing. The chemical reaction was probably intensified by the cold temperatures, as the wedges were placed in the fridge afterward.
8. Why Do Hands Smell Like Coins?
Coins often leave behind a lingering metallic scent on our fingers. In 2006, German scientists discovered that this odor wasn’t from the coins themselves, but from the human skin.
The study involved seven volunteers handling objects containing iron. The participants noted a strong metallic smell on their hands, and gas samples taken from their skin helped identify the cause of the odor. It was a compound called 1-octen-2-one, which forms when skin oils break down.
It seems that when a person touches something with iron, their sweat donates two electrons to each iron atom, making the atoms negatively charged. This interaction with skin oils causes the oils to decompose, producing 1-octen-2-one molecules. The smell we detect is not from the iron in the coin, but rather a type of body odor.
7. Iron Volcanoes
Space volcanoes are quite peculiar. For instance, certain planets have cryovolcanoes, which erupt with water instead of lava. A 2019 scientific paper proposed the possibility of a completely new type of volcanism. While iron volcanoes are not present on Earth, there is a chance that metallic asteroids in our solar system once experienced them.
Today, the solar system is far too cold for asteroids to hold molten metal, but billions of years ago, things were very different. Some asteroids originated as small planets. Collisions stripped the planetesimals down to their liquid metal cores. As these cores solidified, the process likely involved temporary volcanic activity at the surface.
What’s fascinating is that if these eruptions released pure iron, it would have been quite a different sight than Earth’s familiar lava flows. Rather than thick, viscous lava, iron would have likely spread as thin sheets due to its lower viscosity.
To verify the possibility of such volcanoes, scientists need to investigate a metallic asteroid. NASA is planning to send a spacecraft to examine Psyche, the largest of these asteroids, in 2022. However, the spacecraft won’t arrive until 2026, so evidence of iron volcanoes will have to wait a few more years.
6. A River Of Iron
In recent years, three satellites discovered an unusual phenomenon. These satellites, designed to monitor the planet’s magnetic field, tracked strange magnetic flux lobes beneath Siberia and Alaska. It soon became apparent that these lobes were shifting. The cause was extraordinary.
The magnetic lobes were being pushed toward Europe by a colossal river of iron. This molten river stretched 3,000 kilometers (1,864 miles) beneath the Earth's surface and spanned 420 kilometers (260 miles) in width. It was nearly as hot as the Sun’s surface and was accelerating at an unusual rate.
Over the past 20 years, the speed of this dangerous river has nearly tripled. Although the cause of this acceleration remains a mystery, it might be a natural phenomenon that has never been observed before.
Researchers can track the progress of the stream through variations in the magnetic field, which currently shifts at a rate of 50 kilometers (31 miles) per year. If this represents an unknown cycle, uncovering its full mechanism could help predict future fluctuations in Earth's magnetic field.
5. Emergency Adjustment to Magnetic North
Every five years, the World Magnetic Model (WMM) is revised by the British Geological Survey and NOAA. Given that magnetic north is constantly shifting, the calibration of both advanced navigation systems and basic compasses depends on the WMM.
The pole’s movement is driven by erratic magnetic forces from within the Earth's iron core. While Canada held the pole for centuries, since 1860, it has been steadily drifting toward Siberia.
The pole traveled 2,414 kilometers (1,500 miles) and crossed the international date line in 2017. While its movement was faster during the 1980s, it slowed by the time the last World Magnetic Model (WMM) was updated in 2015. The next update wasn’t expected until the end of 2019.
But just months before the scheduled update, scientists observed that the deceleration had not continued as forecast. The pole had accelerated once again, shifting so drastically that NOAA and the British Geological Survey had to issue an emergency WMM update.
Though the cause of the acceleration remains uncertain, possible factors include the iron river in Canada and a strong magnetic anomaly in Siberia that pulls the pole toward the east.
4. Enigmatic Iron Spheres
As the vastness of bird migration became understood, a puzzling question arose: How do birds navigate between oceans and continents to reach their destinations? Eventually, scientists realized that birds use the Earth’s magnetic field, but this brought another mystery—how do they sense the magnetic field?
In 2013, an intriguing discovery in birds suggested a possible link to their sensitivity to magnetism. Researchers studied hair cells in the ear, which are responsible for detecting sound and gravity. Remarkably, each of these cells contained an iron ball.
This discovery was true for every bird species examined, with all of them carrying these metal spheres. The finding was extraordinary—not only because of their widespread presence but also because the iron balls had managed to evade scientific detection for so long. While their exact role remains uncertain, these balls might be part of the mysterious magnetoreceptors that birds rely on to navigate Earth’s magnetic pathways.
3. Ancient Vessels Containing a Rare Compound
Jian ceramics, crafted in China during the Song dynasty between AD 960 and 1279, were prized for their functional beauty. Tea connoisseurs, especially from Japan, valued the bowls for their ability to retain heat. These vessels were also noted for their striking appearance. The dark glaze covered their surfaces, showcasing unique patterns like ‘hare’s fur,’ ‘partridge spots,’ or ‘oil spots,’ all formed by molten iron in the glaze.
In 2014, Jian pottery underwent detailed analysis of its chemical makeup and microstructure. The results revealed an astonishing discovery: the bowls, particularly the ‘oil spot’ type, contained significant amounts of pure epsilon-phase iron oxide.
Scientists are fervently searching for this compound. It holds the potential to create stronger, non-toxic, and corrosion-resistant magnets, paving the way for improved electronics. Additionally, it could lower the cost of producing these magnets.
Despite numerous attempts, creating pure epsilon-phase iron oxide has remained elusive. The Jian glaze might be the key to unlocking the secret recipe for this rare compound, which researchers hope to replicate in the future.
2. Iron That Mimics Platinum
Alchemists have tried for centuries to turn lead into gold. None of them ever succeeded, but the closest thing to transmutation happened in 2012. At Princeton University, chemist Paul Chirik tricked other molecules into thinking that iron was platinum. The consequences could be far-reaching.
Iron is much cheaper than platinum, a precious metal that cost about $22,000 a pound in 2012. In comparison, a pound of iron was $0.50 back then. If a cheap pseudo-platinum could replace the real thing, then the costs of technology involving the precious metal might also drop. Platinum is used as a catalyst to produce things like high-octane fuel and pharmaceuticals.
How did Chirik achieve this feat?
His solution was simple. He wrapped an iron molecule in a ligand, which is another molecule but organic. The ligand changed the number of electrons that bonded with other chemicals, making the latter react to the iron as if it were platinum.
1. Iron Is Disappearing
The iron on Earth is mysteriously disappearing, and the cause remains unknown. Initially, volcanic conditions were suspected to be responsible, with a theory suggesting that a mineral called magnetite absorbed iron when rocks melted deep below the surface.
However, this theory didn’t withstand further analysis. Iron depletion happens more rapidly in regions with a thicker Earth’s crust. If magnetite were indeed the cause, it would have been found in greater quantities in those areas of depletion.
In 2018, scientists identified a new suspect mineral in these regions: garnet, a mineral resembling ruby, which is rich in iron. Despite the new discovery, the belief that iron was being extracted from lava persisted. To validate garnet’s involvement, researchers examined deep-crust rocks thrown from volcanoes millions of years ago.
Indeed, these ancient rocks were filled with the shimmering mineral. The study also analyzed a global database of volcanic rocks collected worldwide, revealing that magma with higher garnet content contained less iron. Although further studies are required to confirm this, garnet appears to be a strong contender in this mystery.
