Iron from space helps uncover the antiquity of one of Spain’s greatest treasures

One of the most important and mysterious Bronze Age discoveries appears to have incorporated meteoric iron. The discovery could resolve confusion about the age of not only the ironwork, but also the gold hoard in which they were buried.

The Treasure of Villena was discovered in 1963 in what is now eastern Spain. The 59 bracelets, bowls, and various items are most famous for their rich gold, but more interesting is the iron from which two of the items were made. These were the oldest pieces of iron found on the Iberian Peninsula and were thought to be at least 3,000 years old based on the accompanying riches. The origin of the entire treasure is mysterious enough given the lack of evidence of the civilization that made them, and the presence of clearly Bronze Age items with iron pieces deepened the mystery.

But long before humans learned to mine and smelt iron, we were using iron from meteorites found on the Earth’s surface. Most famously, Tutankhamun carried a dagger forged from meteoric iron, and the boy pharaoh’s possession of the dagger indicates the immense value placed on such items. The ability to process the mixture of iron, nickel, and sometimes cobalt known as meteorite iron may have developed independently in many places, as pre-Iron Age examples are found not only in the Middle East but also in North America, southern Africa, and Tibet. Must. .

One piece of iron is a hollow hemisphere partially covered with gold (called a cap or pommel), and the other is a bracelet. Their purpose is unknown, but at face value their presence indicates that the treasure dates to the Iron Age, but not at the very beginning when ironwork was new enough to be of great value. . But if so, what are they doing with so much gold like in the Bronze Age?

However, if the iron from which these two parts were made came from heaven rather than earth, there would be no contradiction.

Naturally, archaeologists have long been keen to test shingles. But the combination of the extremely delicate nature of most ancient irons due to corrosion and the desire to protect the items from damaging testing methods created obstacles. The increased availability of non-destructive testing changed the situation, allowing former museum curator Salvador Rovira-Llorens and his co-authors to investigate the composition of the work.

Portable X-ray fluorescence analysis gave uncertain results, so the researchers turned to mass spectrometry applied to tiny samples. They found that the percentage of nickel in the cap (5.5 percent) is highly consistent with known iron meteorites and far exceeds what is typically found in terrestrial deposits. Preliminary measurements on the bracelet, on the other hand, gave a decidedly ambiguous result of 2.8%.

However, corrosion can leach more nickel than iron, reducing its concentration. Deeper analysis revealed more nickel in internal areas less exposed to air and water, indicating that the bracelet was also made from meteorite iron. Indeed, they have the same uncorroded composition and are likely from the same meteorite. However, it has so far been impossible to match the composition to a specific meteorite.

“According to the available data, the cap and bracelet from the Villena treasure are the first two items currently attributed to meteoric iron in the Iberian Peninsula, before the widespread production of terrestrial iron began. , consistent with the Late Bronze Age chronology. Iron,” the authors write.

Outside of Greenland, almost all terrestrial iron is in the form of iron oxide, but Bronze Age people did not have the technology to reduce iron oxide. Not only did meteorites avoid that need, but iron-nickel alloys were more resistant to corrosion, even after pure iron became available. This extremely rare product was the terrestrial equivalent of Valyrian steel in Westeros, and its extreme rarity gave it immense value.

The study is published in Trabajos de Prehistoria.