Meteoric iron

Some metal falls from space.

This metal is made of iron and nickel. It comes from rocks in the sky. Long ago, people used it for tools.

They made knives and sharp blades. Some people even made a dagger. A king named Tutankhamun had one too. This metal is very special. It is one of the only ways to find iron in nature. It is a wonder from the stars.

Meteoric iron is a metal from space. It is found in meteorites. This metal is made of iron and nickel. It mostly contains two minerals. These are called kamacite and taenite.

When this metal cools, it forms a pattern. This is called the Widmanstätten pattern. It looks like thin lines. Scientists can also see Neumann lines. These are fine lines caused by impacts.

Long ago, people used this metal for many things. They used it before they knew how to make iron from rocks. In ancient Egypt, people made iron beads. In Mesopotamia, people called it an-bar. They thought it was sacred. King Tutankhamun even had a dagger made from it. In the Americas, the Inuit used it for harpoon tips.

This metal also affects our air. When meteorites fall, they rub against the air. This is called ablation. It lets out small bits of iron. These bits can change ozone in the sky. This may make orange colors in the light of the upper atmosphere.

Meteoric iron is a special kind of metal found in space. It comes from the very early parts of our solar system. This metal is a mix of iron and nickel. It mostly contains two minerals called kamacite and taenite.

Kamacite is a body-centered cubic alloy. Taenite is a face-centered cubic alloy. These two minerals make up most of the metal. You can tell it apart from iron found on Earth by its structure. It also has more nickel and less carbon than Earth iron.

This metal shows amazing patterns when it cools down. One famous pattern is the Widmanstätten pattern. This happens when kamacite separates from taenite into thin layers. There is also something called plessite. This is a very fine mix of the two minerals. You might also see Neumann lines in the metal. These are fine lines caused by the force of an impact.

People have used this space metal for thousands of years. Long ago, people did not know how to make iron from rocks. Meteoric iron was the only way to get pure iron. In ancient Egypt, people made beads from it around 3200 BC. In Mesopotamia, people called this metal "an-bar." They thought the metal was sacred. They used it to make special objects for rituals.

Many famous treasures are made from meteoric iron. An iron dagger from Alaca Höyük dates to 2500 BC. An iron pendant from Syria was made around 2300 BC. King Tutankhamun had a famous iron dagger from 1350 BC. This dagger has the same metal mix as a local meteorite. In China, people made iron axes from it around 1400 BC. Even in Switzerland, an arrowhead from 900 BC was made from space iron.

This metal also changes the air around our planet. When meteorites fall, they rub against the atmosphere. This process is called ablation. It wears away the outer parts of the meteorite. This releases iron atoms into the high sky. These atoms can react with ozone to form iron oxide. This may create orange colors in the light of the upper atmosphere.

Meteoric iron is a unique, naturally occurring native metal found within meteorites. It is a remnant from the protoplanetary disk, which is the swirling cloud of material that formed our early solar system. Unlike most iron found on Earth, which is usually trapped inside rocks called ores, meteoric iron is a pure metal. It is composed primarily of the elements iron and nickel. Scientists can identify it by looking at its specific chemical makeup and its internal structure.

The mineralogy of meteoric iron is defined by its specific alloys. The bulk of this metal consists of two main mineral phases: taenite and kamacite. Taenite is a face-centered cubic alloy, meaning its atoms are arranged in a specific geometric pattern. Kamacite is a body-centered cubic iron-nickel alloy. Taenite typically contains between 20% and 65% nickel. In contrast, kamacite is much lower in nickel, usually containing only 5% to 10%. Other rare phases, such as antitaenite, may also be present in small amounts.

When meteoric iron cools very slowly, it creates beautiful and complex internal structures. One famous example is the Widmanstätten pattern. This pattern forms when kamacite separates or "exsolves" from the taenite in the form of thin layers called lamellas. Between these layers, you might find plessite, which is a very fine-grained intergrowth of the two minerals. If the metal has been hit by a massive force, it may develop Neumann lines. These are fine lines that run through the kamacite crystals due to impact-related deformation.

Before humans learned the complex process of iron smelting, meteoric iron was one of the only sources of pure iron metal. This made it an incredibly valuable and rare material for ancient civilizations. In Mesopotamia, the Sumer and Akkadian empires treated the metal as sacred. They even had a special name for it: "an-bar." Because it fell from the sky, it was used to create special ritual objects long before people could process terrestrial iron from the ground.

Archaeologists have found many incredible artifacts made from this space metal across the globe. In Egypt, iron beads found near Gerzeh date back to approximately 3200 BC. These beads contain about 7.5% nickel, proving they are meteoritic. Another famous example is the iron dagger found in the tomb of Tutankhamun, dated to around 1350 BC. Geochemical analysis shows the proportions of iron, nickel, and cobalt in the dagger match a meteorite from an ancient shower in that area. Other finds include a 2500 BC dagger from Alaca Höyük and iron axes from Shang dynasty China around 1400 BC.

Different cultures utilized meteoric iron in unique ways based on their locations. The Inuit people in the Americas used fragments of the Cape York meteorite to craft knives, harpoon tips, and lance heads. In Africa, the Nama people of Namibia used pieces of the Gibeon meteorite for centuries. In Tibet, there are reports of meteorites being used to make various items, including a statue known as the "Iron Man." Even as late as 1854, a piece of the Cranbourne meteorite was used to make a horseshoe.

Meteoric iron does more than just provide tools; it also affects the Earth's atmosphere. As meteorites descend, they undergo a process called ablation. This is when the outer parts of the meteorite are worn away by the heat of the atmosphere. This ablation releases iron atoms into the upper atmosphere. These free iron atoms can react with ozone (O3) to create iron oxide (FeO). This chemical reaction may be the reason for the orange spectrographic bands seen in the spectrum of the upper atmosphere.