Since it was found in 1911, an Egyptian iron bead has sparked wonder and debate over how it was produced — made around 3,300 BC, it predates the region's first known iron smelting by thousands of years. Now, researchers say the iron was made in space and delivered to Earth via meteorite.
"Tube-shaped beads excavated from grave pits at the prehistoric Gerzeh cemetery, approximately 3300 BCE, represent the earliest known use of iron in Egypt," the scientists write in the May 20 issue of Meteoritics and Planetary Science.
Early studies of the beads found their iron to be rich in nickel, a key indicator that the metal originated from a meteorite. But researchers contested that idea in the 1980s, suggesting the metal was instead the result of early attempts at smelting.
After analyzing one of the beads with scanning electron microscopes and CT scans, the researchers say they found that "microstructural and chemical analysis of a Gerzeh iron bead is consistent with a cold-worked iron meteorite."
At more than 5,000 years old, the irreplaceable beads could not be cut open. So, as Jo Marchant reports for Nature (where we first saw the story), scientist Diane Johnson of Britain's Open University and her colleagues borrowed one of the beads from the Manchester Museum. The artifact's cracked and peeling surface offered "little windows" into its interior, Johnson tells Marchant.
"Our results show that the first known example of the use of iron in Egypt was produced from a meteorite," the researchers conclude, adding that "its celestial origin having implications for both the perception of meteorite iron by ancient Egyptians and the development of metallurgical knowledge in the Nile Valley."
Descending from the sky, the rare (at the time) metal also helped to shape Egypt's cultural and religious development, the researchers believe.
"Today, we see iron first and foremost as a practical, rather dull metal. To the ancient Egyptians, however, it was a rare and beautiful material which, as it fell from the sky, surely had some magical/religious properties," co-author and egyptologist Joyce Tyldesley of the University of Manchester said in a news release about the study. "They therefore used this remarkable metal to create small objects of beauty and religious significance which were so important to them that they chose to include them in their graves."