“Metorites in Ancient Egypt” Diane Johnson (EEG Talk)

On Sunday Diane Johnson came to the Essex Egyptology Group meeting to talk to us about meteorites in Ancient Egypt. She’s a physicist who works at the Open University on meteorites, and is also interested in Ancient Egypt. She is combining the two by examining ancient iron objects from Egypt to see if they derive from meteorite iron & has recently published a paper about a bead found in a pre-historic tomb.

Johnson opened her talk with a discussion of what meteorites are (in more detail than “rocks that fall from space”). There are three types – rocky, iron & rocky-iron. The iron ones are the ones with most relevance for the rest of the talk, and she briefly discussed their composition. Iron in meteorites is normally nickel rich, around 10%ish (I think she said) and the nickel rich vs. non-nickel rich patterning in the meteorite generally shows similar characteristics across different meteorites. In her introduction she also talked about evidence that meteorites are used as cult objects across a variety of cultures both ancient & modern. There’s some evidence of this in Ancient Egypt – for instance the benben stone, a cult object in the solar temple at Heliopolis, might’ve been a meteorite.

The bulk of the talk was about various iron objects that’ve been found from Ancient Egypt, and discussing whether they were made of metal from meteorites or from terrestrial iron. She also considered whether they were made locally in Egypt or imported from somewhere else. The oldest of these items are seven beads that were excavated from a pre-dynastic burial in Gerzeh, and Johnson has been able to perform some in depth analysis on one of them (this is the subject of her recent paper). She used two techniques to look at the structure & composition of the bead – scanning electron microscopy (SEM) and X-ray CT scanning. The SEM technique she used not only provides high magnification images of the surface of the bead but also details of the molecular composition of the surface. The X-ray CT scans show details of the interior of the object. So Johnson was able to build up quite a detailed picture of the bead’s composition, structure and construction without having to damage the bead in any way. Most of the bead was oxidised iron, but throughout it there were streaks of still metallic nickel-rich iron in a pattern characteristic of meteorite iron. The bead had been made out of a small piece of iron that had been crudely hammered flat then bent round to form the bead. It was strung on flax thread, fibres of which were actually still present inside the bead and visible with both imaging techniques (although not apparent to the naked eye). That was the bit I was most impressed by – thread surviving in a state where it was still identifiable for ~5,000 years!

Of the handful of other pre-Egyptian Iron Age objects she talked about the one that most stuck in my mind was the dagger found on Tutankhamun’s body. As with the beads in the pre-dynastic grave this was clearly treated as a precious object (rather than the functional way we think about iron today). Johnson said that from the composition & style of working of the knife blade she thought that this was a piece of high quality smelted terrestrial iron which had been imported from a different region. In connection with that she talked about the Amarna letters, one of which details a list of gifts from the Mittani King to Amenhotep III. In this list there are a few iron knives mentioned, one of which uses a different word for the iron blade to the others – this word is thought to mean steel, and Johnson thinks it’s plausible that it refers to this dagger that Tutankhamun was buried with. (Obviously there’s no proof one way or the other.)

At the end of her talk she discussed textual references to iron in Egyptian texts. One of the things she talked about was how the word for iron undergoes a shift, I think she said it was during the 19th Dynasty. Before then it was just iron, afterwards it was consistently iron-from-the-sky – even for iron we are sure was smelted terrestrial iron so not from the sky at all. So she has put some thought into what might cause the word to change like this, and she thinks that a plausible cause is a meteorite strike in the far southwest of Egypt. This is the Kamil Crater and it is known to be less than 5,000 years old (due to the archaeology of the site) but hasn’t been dated more precisely than that. It was an iron rich meteorite which exploded on or just before impact scattering thousands of kilos of small fragments of iron around the site. Johnson noted that there’s no reference to it in the Egyptian texts, but the Egyptian relationship to writing things down isn’t the same as ours – they believed that writing it down preserved the event & so didn’t write about troubling things (like losing wars). So possibly the meteorite was seen arriving, and the Egyptians visited the site and found iron on the ground around & in the crater and now they “knew where iron came from”. All speculation, but worth investigating.

This was a very interesting talk, about a subject that is fairly unusual with its mix of hard science & history. In the question session afterwards Diane Johnson mentioned she’s trying to get funding for more work on the subject, because so far she’s done it all in her free time. I hope she manages! 🙂