Egyptian artefacts came from outer space
Heavenly gift Some of the earliest iron artefacts ever found - funeral beads strung around bodies in a 5000-year-old Egyptian cemetery - came from outer space, archaeologists have confirmed.
High-tech scanning of the beads, discovered by British archaeologists in the Lower Egypt village of el-Gerzeh in 1911, shows the metal came from a meteorite that landed on Earth.
The nine small beads, stored at the University College London (UCL) Petrie Museum, come from two burial sites dated to around 3200 BC, where they were found in necklaces along with exotic terrestrial minerals such as lapis lazuli, agate and gold.
Meteorite iron is an alloy that has a different composition from terrestrial iron.
The scientists teased out a signature of the elements in the beads through a non-destructive ID test called prompt-gamma neutron activation analysis (PGAA).
Under this, a sample is bathed in low-energy beams of neutrons. Elements in the sample absorb some of the neutrons and emit gamma rays in response, the level of which provides the telltale signs of what is inside.
According to the study, which appears in the Journal of Archaeological Science, the team found higher than normal concentrations of nickel, phosphorus, cobalt and germanium in the iron beads.
X-ray scanners, meanwhile, showed that the meteorite iron had been repeatedly heated and hammered to make the precious jewels for the afterlife.
The researchers say the finding shows that the Egyptians were already advanced in the art in smithing by the fourth millennium BC.
Meteoritic iron is much harder and more brittle than copper, the commonly-worked material of the time.
"They were rolled and hammered into shape," says Thilo Rehren, a UCL professor of archaeology.
"This is very different technology from the usual stone bead drilling, and shows quite an advanced understanding of how the metal smiths worked this rather difficult material."
It's not the first time meteorite iron has been found among Egyptian jewellery.
In May, researchers from Open University and the University of Manchester published a paper in the journal Meteoritics and Planetary Science that showed iron beads found in the burial site were extraterrestrial in origin.