Archive for June 1st, 2016

Tutankhamun’s dagger made from meteoric iron

Wednesday, June 1st, 2016

When Howard Carter opened the sarcophagus of King Tutankhamun and unwrapped the mummy in 1925, three years after his discovery of the tomb, he found 107 objects placed in the linen bandages. One of them was an iron dagger with a gold handle elaborately decorated with cloisonné enamel, gold granulation in geometric patterns and a crystal pommel. Its sheath was made of gold with a lily motif engraved on one side and feathers terminating in a jackal head at the peak of the sheath on the other side. It was found on his right thigh.

Iron is very rare in Egyptian tombs. Bronze was the dominant metal in funerary artifacts until the Assyrian Occupation (656-639 B.C.), 600 years after iron production became widespread elsewhere around the Mediterranean. When iron has been found in a funerary context, archaeologists have suspected it was of extra-terrestrial origin. Since it falls from the sky, it would have been seen as a direct gift from the gods. Iron meteorite impact craters have been discovered in Egypt. One found in southern Egypt in 2008 dates to within 5,000 years, so it could well have been a source of godly iron for the ancients.

It’s also possible that the iron in Tutankhamun’s dagger has more earthly origins. Iron was a byproduct of bronze and copper smelting, metals Egypt produced in abundance, and there are references in the 14th century Amarna letters to gifts of valuable iron from the King of Mitanni. There has been much debate on the question since 1925. Two studies done on the metal of the dagger had conflicting results. Iron meteorites are composed mainly of iron and nickel with trace amounts of cobalt, phosphorus, sulfur and carbon. The nickel content in iron produced from ore is no more than 4 percentage by mass (wt%), while in iron meteorites it’s at least 5 wt% and can go up to 35 wt%. The first study in 1970 found high nickel content indicative of meteoric iron, but it was never published and the methodology is unknown. A 1994 X-ray fluorescence (XRF) spectrometry analysis found a nickel content of 2.8 wt%, which is too low for meteoritic iron.

Now a new study by an international team of researchers has used state-of-the-art XRF technology to determine whether the iron in King Tutankhamun’s dagger is of meteoric origin. Italian and Egyptian researchers from the Politecnico di Milano, the University of Pisa, the Cairo Museum, the University of Fayoum, and the Politecnico di Torino compared XRF measurements of two areas of Tutankhamun’s dagger, 11 meteorites of clear composition and 11 examples of certified steel. Their analysis found that the dagger’s blade is 11 wt% nickel, which can only be meteoritic iron. The amount of cobalt, .6 wt%, is also consistent with the ratio of nickel to cobalt found in iron meteorites.

Our finding confirms that excavations of important burials, including that of King Tutankhamun, have uncovered pre-Iron Age artifacts of meteoritic origin (Johnson et al. 2013).

As the only two valuable iron artifacts from ancient Egypt so far accurately analyzed are of meteoritic origin, we suggest that ancient Egyptian attributed great value to meteoritic iron for the production of fine ornamental or ceremonial objects up until the 14th C. BCE. Smelting of iron, if any, has likely produced low-quality iron to be forged into precious objects. In this context, the high manufacturing quality of Tutankhamun’s dagger blade is evidence of early successful iron smithing in the 14th C. BCE. Indeed, only further in situ, nondestructive compositional analysis of other time-constrained ancient iron artifacts present in world collections, which include the other iron objects discovered in Tutankhamun’s tomb, will provide significant insights into the use of meteoritic iron and into the reconstruction of the evolution of the metal working technologies in the Mediterranean.






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