Scientists have examined 5,000-year-old beads from Egypt. Using X-rays and neutron activation, they conclusively established that the material comes from space. They also saw how the material – iron meteorite – had been processed. The ancient Egyptians used techniques that were far ahead of the Iron Age.
The beads in question dating from circa 3200 BC are in the Petrie Museum of Egyptian Archeology from University College London (UCL). They were excavated in 1911 from two tombs near the village of Gerzeh, a few tens of kilometers from Cairo. Between 200 and 300 tombs can be found here, dating from a time even before that of the pharaohs.
Participating scientist Thilo Rehren (UCL Archaeology, Qatar) about the research:“Little is known about the individuals who were buried here. We assume it is a community of farmers and fishermen. The contents of most tombs are about the same, from which we can conclude that society was quite egalitarian. However, the first signs of social stratification can already be seen here. In one of the graves was a large harpoon of copper and a stone in the shape of a fish.”
“The iron meteorite beads were scattered in the tombs of two boys, along with other valuables. Beads of lapis lazuli from Afghanistan, gold, ivory and jack-neck teeth. But also shreds of resin from a tree and ordinary stones.”
“The latter probably had personal value:even today, boys still take home everything that interests them to keep. However, nothing points to a special position of these boys in their society. It's a shame they didn't live longer. Their curiosity would surely have made them the researchers of their time.”
New technique, new result
At the time of the excavations in 1911, archaeologists already thought that the material from the beads might have come from outer space, but they could not prove it. The beads were already completely corroded when they were discovered and could therefore also have been made from the earth's magnetic stone, because of the resemblance to corroded iron.
In the meantime, science has not stood still and nowadays we can determine the composition of materials by means of neutron activation and gamma rays, without having to destroy it. This is exactly what the scientists at UCL have done. Scanning the beads, the researchers measured high concentrations of the elements nickel, cobalt, phosphorus and germanium, which are characteristic of iron meteorites. These substances can also be found in iron ore, but only in very small quantities.
Rehren commented on the results of the study:“The most exciting result is that for the first time we have been able to unequivocally demonstrate the presence of specific trace elements, such as cobalt and germanium, in the beads. And in amounts that only occur in iron meteorites.” So there is no longer any doubt that the beads come straight from space.
Iron Age advances
Another important result of the research is that it is now clear how the more than 5,000-year-old beads came about. The ancient Egyptians used copper tools and stone hammers to gently flatten the iron meteorite pieces as they forged. They rolled the thin leaves into tubes and these tubes served as beads on a valuable chain. However, forging iron meteorite – a mixture of iron and nickel – differed substantially from traditional processing techniques, such as chopping or piercing stone beads.
So the Egyptians mastered the forging of the hard but brittle iron meteorite as early as the fourth millennium BC and not until the Iron Age, which began some 2,000 years later. From that period, iron was extracted from iron ore by means of heating. The metalworkers from Egypt thus apparently had experience in smelting and processing iron for almost two millennia. According to the researchers, this knowledge was essential for the development of the process by which iron could be extracted from iron ore.
The Egyptians, however, were not the only ones to make artifacts from iron meteorites before the Iron Age. Rehren:“Gerzeh's carved beads are the oldest, but bronze-age iron meteorite artifacts can be found all over the world; from Siberia to North America and from Turkey to Indonesia. Not surprising, since meteorite has been falling from the sky everywhere for billions of years. The material was therefore not super rare. The Sahara in particular was – and still is – a good place to find debris:they stand out well in the white sand. This also applies to the ice and snow landscape of Antarctica, but we can assume that the Egyptians did not get there…”
Gift from the gods
From the Iron Age, iron would become the most popular metal. It would replace bronze and copper, especially as consumables. But until then, the ancient Egyptians made beautiful artifacts from their iron meteorite. From the beads they make necklaces, along with other valuable materials, such as gold and ivory. Rehren:“Iron meteorite was only used for decoration, like beads on a chain. Even a Tutankhamun dagger, made of iron meteorite with a gold handle, was purely for show, not for use.”
According to the researchers, the processing of both iron meteorite and precious metal in jewelry shows how much value the Egyptians attached to the special metal. It is even thought that they saw the iron meteorite as a gift from the gods. This latter theory comes from another group of English scientists, who have examined the same beads. They came out with their research results a few months ago.
Rehren on the differences between the studies:“The scientists at The University of Manchester have focused more on the spiritual value the Egyptians placed on the iron meteorite. We were mainly concerned with the way the metalworkers worked the iron. In addition, we used other techniques to determine that this was really material from space. Manchester used the scanning electron microscope and could only analyze the surface of the material.”
“Our scientists were able to analyze the entire material using gamma rays (PGAA). Our method is the only method that can conclusively determine that the material under investigation contained germanium, the essential component of iron meteorite. Manchester could only show with the scanning electron microscope that the beads contained nickel and cobalt. However, these components have also been found in iron objects made by human hands. Germanium makes the real difference.”