Among a hoard of glittering gold treasures from the Iberian Bronze Age, a pair of rusted objects may be the most precious of all.
A dull bracelet and a rusted hollow hemisphere decorated with gold are fakes, researchers have found, not of metal from underground, but of iron from meteorites that fell from the sky.
The discovery, led by the now retired head of conservation at the National Archaeological Museum in Spain, Salvador Rovira-Llorens, was revealed in a document in 2024, and suggests that metalworking technology and techniques in Iberia more than 3,000 years ago were much more advanced than we thought.
Related: World’s Oldest Earth Rock Discovered in Indonesian Cave
The Treasure of Villena, as the cache of 66 mostly gold objects is known, was discovered more than 60 years ago in 1963 in what is now Alicante in Spain, and since then it has come to be considered one of the most important examples of Bronze Age gold work in the Iberian Peninsula, and in all of Europe.
Watch the video below for a summary:
Determining the age of the collection was somewhat difficult, thanks to two objects: a small hemisphere, hollow inside, believed to be part of a scepter or sword neck; and one bracelet, like a torc.
Both have what archaeologists have described as an “iron” appearance – that is, they appear to be made of iron.
In the Iberian Peninsula, the Iron Age – where molten terrestrial iron began to replace bronze – did not begin until around 850 BCE
The problem is that the gold materials have been dated to between 1500 and 1200 BCE So working out where the ferrous-looking artifacts fit in the context of the Villena Treasure has been something of a puzzle.
But iron ore from the Earth’s crust is not the only source of malleable iron. There are a number of pre-Iron Age iron artifacts around the world that have been forged from meteorites.
Perhaps the most famous is the meteoritic iron sword of the Pharaoh Tutankhamun, but there are other Bronze Age weapons made from the material, and they were highly prized.
There is a way to tell the difference: iron from meteorites has a much higher nickel content than iron mined from Earth’s soil.
Listen now to ScienceAlert’s Casting Call
Therefore the researchers obtained permission from the Municipal Archaeological Museum of Villena, which houses the collection, to carefully test the two artifacts, and determine how much nickel they contained.
They carefully sampled the two artifacts and subjected the material to mass spectrometry to determine their composition.
Despite the high degree of corrosion, which changes the elemental composition of the artifact, the results strongly suggest that both the hemisphere and the bracelet were made of meteoritic iron.
This neatly resolves the dilemma of how the two artifacts align with the rest of the collection: They were made around the same period, dating back to around 1400 to 1200 BCE
“The available data suggest that the cap and the bracelet from the Treasure of Villena would currently be the first two pieces attributable to meteoritic iron in the Iberian Peninsula,” the researchers explain in their paper, “which is compatible with a Late Bronze chronology, before the beginning of the widespread production of terrestrial iron.”
Now, because the objects are so corroded, the results are not conclusive. But there are more recent, non-invasive techniques that can be applied to the objects to obtain a more detailed set of data that will help shape the findings, the team suggests.
The findings were published in Works of Prehistory.
An earlier version of this article was published in February 2024.