Throughout history, mirrors have always been a source of fascination across cultures. At least that makes sense for us humans, who, along with apes, are the only animals that can recognize their own reflections. The word itself comes from the Latin word mirare, meaning “to be amazed.” As far as we know, the earliest known mirrors date back to 6000 BCE, and were found at a Late Neolithic site in Turkey. But what about Ancient Egypt?

Study. This is exactly what the latest study, published in the Journal of Archaeological Science: Reports and carried out by a team of researchers from the University of Liverpool, is all about. Led by Elizabeth Thomas, the group started from a well-known idea: mirrors were known to have played a fundamental role in ancient Egypt, both culturally and religiously, but little was known about how they were produced.

The result, as we shall see, revealed the craftsmen’s deep knowledge of metallurgical techniques and the use of mainly three types of alloys in manufacture: arsenical copper, copper-tin alloy, and ternary alloy of arsenical copper with tin.

Chemical analysis. Thomas said they looked at the known facts before they started, including: In ancient Egypt, mirrors were highly polished copper, bronze or gold disks representing the sun and with handles in the shape of a papyrus stalk or the figure of Hathor, the Egyptian goddess associated with beauty and rebirth.

So the first thing they did was to study the metallurgy of nineteen Egyptian mirrors, covering a broad chronological period from the Old Kingdom to the Late Period. This was made possible by scanning electron microscopy, a technique that has energy distributions over the years of their manufacture.

Mirrors analyzed

Three keys. As we said, the first thing they discovered is that Ancient Egyptian artisans almost always used three types of alloys in the production of mirrors: arsenic copper, copper and tin alloy, and ternary alloy of arsenic copper with tin. It is also detailed in the study that in the analyzed mirrors the composition is repeated with about 5% arsenic or tin.

What does this mean? The team suggests that this indicates a much higher level of control and standardization in the production process than previously known. In fact, this consistency, in addition to confirming how “good” Egyptian craftsmen were at their work and their technical skills, led the researchers to ask other questions. For example, why this specific alloy and not another?

One possible answer. Although it remains a hypothesis, Thomas and his team believe, based on everything that has been found, that it is due to the optimal physical properties of the composition in question, such as hardness and workability, and perhaps even the color that originates from the metal. This is not a trivial idea, because this way they can produce that golden or silver tone in the finished mirror.

In fact, there is evidence of a technique known as surface enrichment in the mirrors analyzed in the study that involves creating a surface layer rich in arsenic, the same layer that gives the mirrors that shiny, silvery appearance, perhaps as an attempt to give them an appearance similar to higher-value ones like silver.

The process of an extraordinary technique. Thomas explains that this type of metallurgical technique for surface enrichment was most likely achieved through a process known as reverse segregation, a complex technique that required intricate knowledge of the metallurgical properties of copper arsenic. It has been suggested that religion may have been key to decisions regarding alloy selection, such as gold reflections or the like.

Finally, the study found something surprising. Microscopic analysis revealed clues to a timeless type of process in which highly standardized production involved repeated cycles of cold hammering and annealing. Such a technique would increase the metal’s hardness, allowing for better polishing and a clearer, more consistent reflection.

Yes, it seems the Egyptians had a whole artisanal metallurgical “industry” well oiled much earlier than we imagine.

Image | Public Domain, Science Museum, Elizabeth Thomas

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