Iron in Egypt came from the sky?
On 24 July Manchester University held a study day to celebrate the 10th anniversary of its Certificate in Egyptology. The day was open to anyone, but, of course, there were quite a few people who had just completed the certificate course and they all got their certificate that day. I was one of these lucky students, but I also took the opportunity to talk to Dr Diane Johnson about the project called Iron from the sky.
SJ: Where does the name ‘Iron from the sky’ come from?
DJ: It comes from the ancient Egyptian for iron. The early hieroglyphic term for iron seemed to be quite a broad term. This originates from a time before we know people were smelting iron ores to produce metallic iron and so we think that this term and the context it was used in and given when it dates from it was quite a broad term. It probably applied to metallic iron and materials with similar appearance or physical properties, which is all very reasonable, but then something interesting happens. Towards the end of the 18th, early 19th Dynasty a new word appears. This literally translates to mean ‘iron from the sky’. There’s a lot of debate as to why it appears at this point in time and no one is really absolutely certain. Obviously because it’s iron from the sky there a strong inference it is iron falling from the sky in the form of meteorite iron. So we thought it was quite a nice name for the project, given that we’re exploring both the occurrences of iron in Egypt and how people perceived it.
Source: Iron in the sky
SJ: You mentioned the term ‘iron from the sky’ appeared around the 18th or 19th Dynasty, but on the website I read that you found proof of meteorite iron dating all the way back to the 4th Dynasty.
DJ: The earliest known examples of meteorite iron in use in Egypt actually date from as early as the Predynastic. So it’s around 3,400 BC that we see examples of worked iron meteorites. They appear to have been either small fragments or were originally bigger pieces which were split using the natural meteorite structure. And then they were probably beaten to some extent. They may have been ground a little, heated and then bent into tube shapes. These early examples were Predynastic beads, excavated from the Gerzeh cemetery.
Source: Iron in the sky
SJ: Is there any theory or proof that later on, when the term ‘iron from the sky’ started to appear, they started realising where it actually comes from and before that they may not have realised?
DJ: It’s very difficult to say, because if we look at the earliest example of Egyptian meteorite iron use, obviously that predates writing, so we don’t have a document to refer to in order to understand what they thought of it. We can’t actually say we’ve found any examples of descriptions of fireballs or impact events or anything like this. So it’s very difficult to say what they thought to meteorite iron coming from the sky. All we can say is what we can infer from objects made from it and their contexts. So you might argue iron was symbolic in many ways. But we don’t have any direct written evidence of what the ancient Egyptian people thought of meteorites.
SJ: Do you see any evolution or change in the type of things they made with meteorite iron through time?
DJ: Yes, absolutely. I should stress as well, we can’t say that meteorite iron was always used, because it probably wasn’t. It’s highly unlikely that a lot of the examples from late antiquity would have been made by smelting iron ores. So much of the iron seen in Egyptology collections today will be made of iron ores that were smelted. In terms of the use of Egyptian iron changing with time, certainly it did if you consider iron in general, from Predynastic times onwards, the early examples are exclusively found in tombs of important people, mainly royalty and kings. Obviously with the Predynastic iron owners it is hard to say exactly who these people were, but from the other objects found in the tombs you can see they were high status people. So it appears that iron was exclusively linked to high status. That’s a strong inference that iron, at that point in time, wasn’t perhaps valued the way we value it today, as a functional material. We tend to see it as being a hard working, strong material and we place value on it for that reason. They seem to place more value on it perhaps because of its exoticness, it’s rarity. It had that certain status symbol aspect to it which seemed to make it desirable.
Just one example: if you look at Tutankhamun, he had quite a number of iron objects in his tomb, including an iron dagger blade. We know from things such as the Armana Letters that kings in the region would send other kings an iron dagger blade considering it a suitable gift for royalty. The Armana Letters reference a blade coming to Amenhotep III from king Tusratta of Mitanni. So we know kings were doing this. If you look at correspondence from Tusratta you can see he doesn’t just do this occasionally, he does this on a regular basis. He sends these things, because perhaps he wants to send a gift, perhaps he wants to apologise for something, but it’s a gift that will keep people happy; a big symbolic thing he does, almost to sweeten people. If he’s promised to do something and he can’t do it, he sends his apologies and he sends a dagger blade. The fact that he does it and he does it consistently would suggest it has the desired affect. As I said, these were very important people so it is a strong indicator of high status.
If you look at later examples, a lot of these, if not all of them, will be smelted iron. You tend to find an occurrence of these in almost any big collection and see they’re practical things. So they’re tools, they’re nails, they’re fish hooks, they’re arrow heads, they’re scale armour. But the point is, they’re all very practical. You seem to get this sudden shift where you go from high status material belonging to kings and leaders, it’s important, rare stuff, and suddenly it goes through a phase where we seem to get this sudden influx of the smelting of iron ores. It becomes much more common and now it just becomes practical. As far as we can tell we don’t see evidence of it strongly suggesting high status. It’s just practical, more like we see it today.
SJ: Could that also be because they then started to find iron they could mine themselves?
DJ: Well, it could be. And this is another interesting aspect of the project that I am hoping to take forward. Because if you look at Egypt geologically, it has quite an abundance of iron ores. The fact that you see people making use of some kind of iron ore, for example from pigments for make-up, from really early times, makes you wonder. People like the Egyptians who could work copper, for example, they knew how to do basic metal manipulation. They knew the ores where there. Why did they not put all this together and start smelting iron ore earlier? We don’t know. It’s difficult to say why the iron age as such started when it did. Traditionally a lot of those early pieces of smelted iron were found in the Delta region so arguments have been made that perhaps the knowledge of smelting iron was brought into Egypt by immigrants. And they could have either utilised iron ores locally or perhaps even brought in a semi processed form of iron ore, but we just don’t know.
SJ: How do you determine if the iron comes from iron ores or from meteorites? How do you tell the difference?
DJ: There’s quite significant fundamental differences in chemistry. Meteorite iron is exclusively rich in nickel. So we do get different types of meteorite iron, but they are all rich in nickel to some extent. Whereas natural iron ores generally speaking don’t contain any nickel. There are possibilities with some of the early smelted examples, looking at them from other parts of the world, that at times when people were experimenting smelting they may have sometimes included minerals for some reason as an ingredient they felt would improve the smelting process. Occasionally these might have been rich in nickel. That could add small amounts of nickel which then sometimes makes it a bit more tricky analytically to work out if it is meteorite or an earlier example of smelted iron. So it’s not always straight forward. Sometimes we then have to look at the structures that have formed when it crystalised to decide if it’s meteorite iron, smelted material or it might be there’s a much lower level chemistry of other elements such as cobalt for example, which again can be very indicative of whether it’s meteorite or iron ore. But it’s quite a specialist thing. You need to understand the chemistry and microstructure to actually understand the difference. It’s not always straight forward.
SJ: I know nothing about meteorites except that they do come from above and they fall down. Do all of them contain some form of iron?
DJ: Not every form of meteorite, no. The iron meteorites in general form at the core of small planets or large asteroids. Basically, the way meteorites form: if you imagine the solar system but before the planets existed, a star died somewhere nearby to us. It expelled lots of gas, some dust swept through, but there would have been a big cloud of rotating gas and dust. If it had significant mass, gravity would pull it all together. The central point would have collapsed down when it reached a critical density. Hydrogen would start to fuse and it would basically form a miniature version of the sun. But then you’ve got all of the material which is left around it. This would slowly condense down and cool and it would start to form solids. Most of these would be silicate based, so this is rocky material. But if these build up to a significant size, again, gravity would start to pull within those bodies. So if you imagine a small asteroid for example, made up of all this primitive stuff, gravity would pull heavy elements, things like metals, iron and nickel, and it would form a core, in much the same way as the earth’s core. It’s the same kind of process how the core would form in a large asteroid or small planet. Then you would get the metal concentrating in the core. This, incidentally, is why on earth we don’t find metallic nickel naturally occurring, because it’s all locked up in the core. It’s the same with meteorite iron. So these bodies impact with each other at some point and split apart. Then the core would separate at times and then you’d get bits of nickeline alloy floating around in space. Then you get other types of meteorites formed, because these would come from higher up from that body. You’d have a core, the mantle and the crust, just like you have on earth. You get all the different types of meteorites. Some are essentially pure metal, but some of them are mixtures of metals and rocky silicate components. Some are mainly silicates and some entirely silicate. It just depends at what depth of the parent body it comes from. Or if some of it’s been recycled again, some of it would have formed planets such as Mars for example. And obviously most of the material you get from very geologically formed bodies like the earth, like Mars, like the moon, you just don’t see that metallic component, because it’s all locked away in the core.
This video explains how meteorites form and shows some of the meteorites found on earth.
Source: meteoritesaustralia on Youtube
SJ: Do you think that ancient Egypt is unique in the use of iron coming from meteorites?
DJ: No, it does happen elsewhere. Particularly if you look at prehistoric cultures there are examples world wide. If, for example, you would just concentrate on that earliest example, the use of meteorite iron in Egypt, they are quite simple little beads, tube shaped beads and, interestingly, you can see almost identical ones made by American Indians, probably by the exact same method. It’s just that this was the material they had. They may have recognised it as special, they might have known it came from the sky, it might have been just a rare material they valued. Interestingly the American Indians would again work these into specific forms and they would use them to bury with the dead in a similar fashion. So clearly either meteorites in general or meteorite iron, because it was unusual, because it was recognised as different, would have value that went just beyond, not necessarily just because it could be worked, it was special. So you do see this world wide and you see these examples at maybe slightly different points in time from China and right across the globe, really. It just depends how hard you look if you find it. It does seem to be quite common world wide.
I would like to thank Diane for taking the time to talk to me. It’s always clear the interview is going well when I ask follow up questions and only get to use two of the prepared questions!
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