Orichalcum: A Lost Metal that we Never Lost?

The ancient Greek philosopher Plato, writing about Atlantis, made mention of a fabulous metal which he called “orichalcum”, literally “mountain copper”. This mysterious element was supposedly second only to gold in value, and was highly prized by the ancients for its beauty and its versatility.

Plato was not the first to mention this precious metal. Our oldest surviving reference to orichalcum comes from Hesiod, writing in the 7th century BC. But it was Plato who really gave us the first details of this material, making the inner sanctum of Atlantis flash with reflected “red light” from the metal.

Of course, Atlantis never existed in this form, at least as envisaged by Plato. This description was a fiction appended to a philosophical argument to make a point, not a real description of a real place. And given this it can be tempting to treat orichalcum as fictional as well.

But it is not so simple. For the story od orichalcum does not begin and end with Plato. We have references to this material for centuries of ancient Greek writings, and that is not all. The Romans, it seems, knew the secret of orichalcum, and they knew how to make it, too.

Roman records of orichalcum are far more useful. They tell us what it is, for starters, and how to make it. There are even surviving examples of the metal retrieved from Roman ruins and shipwrecks, whole ingots of the stuff perfectly preserved.

How is it, then, that we do not know what orichalcum is? The root of the problem may lie in the fact that the Romans might not have known, either.

The Legend of a Lost Metal

The Roman orichalcum is known to us. Most surviving orichalcum artifacts are simply brass, or chalcopyrite, a common ore of copper. The Romans used the word “orichalcum” to describe both materials and this allows us to draw some useful conclusions.

Firstly, the Romans knew of the ancient descriptions of orichalcum, and indeed the alloys they referred to as such would closely match these descriptions. The inner citadel of Plato’s Atlantis would indeed flash with red fire is the walls were lined with copper.

Secondly, however, the Romans may have been mistaken in their association with orichalcum and brass, or copper ore. It is entirely possible the Romans did not know what orichalcum originally was, any more than we do, and that they had simply decided that the Greeks must have been describing brass.

For it is clear that the original Greek orichalcum cannot be the same as the Roman metal. For a start, Greek orichalcum is universally recognized as something that must be mined, a metal brought out of the earth. This is not the case for brass.

In addition to this, the Greeks would have been entirely aware of both brass and chalcopyrite, but they do not identify orichalcum as either. Plato says that in his time the mines which produced this metal were all exhausted, and orichalcum is extremely valuable, although by his time remembered just as a name.

We also know the Romans did not value their orichalcum with the same high esteem as the Greeks gave it. Cicero, writing in the 1st century BC, described what his people knew as orichalcum as very low in value, superficially resembling gold but worth much less.

This would also match the proposed ingots of orichalcum found off the coast in Sicily in 2015, thought to be some 2,100 years old. These were analyzed and found to be copper-zinc alloys with additional small amounts of trace elements. If these are indeed Roman orichalcum, then Roman orichalcum is indeed simple brass.

So, it would seem that we have very little to go on. The Greeks barely remembered the name, had only a vague idea of what orichalcum looked like and where it came from, and no Greek orichalcum survives. The Romans on the other hand may never have known, borrowing a half-forgotten Greek word and using it to add cache to their copper alloys.

Is there a way to rediscover the original material? Is there a way to find a metal, second only to gold, which is mined but was lost millennia ago? The answer, if there even is one, may be more obvious than we think.

The first and most obvious conclusion is that Greek orichalcum did not, in fact, exist. Equally, it may have in fact been an archaic and half-forgotten Greek term for brass, or copper. Both these explanations allow for the Romans to believe they produced orichalcum, and for all we know they may have been right.

The idea of an orichalcum “mine” might therefore have been a mistake of the Greeks. Plato said he barely knew of the metal, and it is possible that he leapt to his own conclusions about how it was sourced.

Would this therefore mean that orichalcum was not in fact a Greek discovery, but a Roman one? In seeking to recover lost secrets of civilizations which were old eve when they came to power, were the Romans innovating as much as excavating?

Or is it possible that there is something out there, of which we have no knowledge? Maybe the Greeks did know something that the Romans did not, and maybe there were mines producing this rare metal which was lost by the time of the Roman Republic, and of which only a crude and misunderstood imitation survives?

One other possibility remains. A particular alloy of copper can be obtained by smelting the copper ore with something called “cadmia” which contains zinc oxide. The resulting alloy is described as very pale in color, but not made with tin. 

Virgil, in his Aeneid describes King Turnus of the Rutuli as wearing a magnificent breastplate “stiff with gold and white orichalc.” This description differs to the red flashes Plato saw, and poses an intriguing question. Could this late reference offer the key? Was orichalcum not a single alloy, but a family of metals?

Short of finding an orichalcum mine, we may never know.

Top Image: Roman orichalcum, which begs the question: how can we not know what this metal is? Well, it seems that perhaps the Romans didn’t know, either (Emanuele riela / CC BY-SA 4.0)