A brilliant archaeologist from Tel Aviv University, Prof. Yuval Goren, has developed a new tool which let archaeologists examine the millenia old clay tablets with cuneiform inscriptions and find out amazing details like “who wrote it”. Goren’s device uses X-ray to reveal hidden information about a tablet’s composition without damaging the precious ancient find itself.
Unfortunately, when the Mesopotamian kings exchanged letters, written in cuneiform on small tablets made out of clay, their post offices didn’t record the sender’s return address. Yet, a more thorough look at the composition of the clay tablets can help today’s archaeologists to determine the origins of this correspondence — which can reveal a great deal about ancient rulers and civilizations. It can offer information about the ancient trade networks, warfare, literature and political ties in the region.
Luckily, the medium the ancient rulers chose to correspond in, clay tablets, is composed of fine-grained materials, often less than two micrometres in size, and the exact composition differs depending on the clay’s geographical origin. Examining chemical composition of the artefacts, rather than the texts, can tell archaeologists more about where the writings were created (or at least, where the clay was sourced) and which other tablets with similar composition they relate to.
Traditionally archaeological scientists have had to take small samples of an artefact –– a chip or a slice –– in order to analyse its soil and clay composition. But as more and more museums and archaeology sites ban these destructive means of investigating archaeological finds, Prof. Yuval Goren of Tel Aviv University’s Department of Archaeology and Ancient Near Eastern Civilizations has developed a new tool that may help save archaeological structures while solving some of its deepest mysteries.
“It’s become a big ethical question,” says Prof. Goren. “Many museums will not allow any more physical sampling of artefacts, and it’s especially problematic for small tablet fragments and stamps which cannot be broken in the process. I had to find another way to know what these artefacts were made of.”
By adapting an off-the-shelf portable x-ray lab tool that analyses the composition of chemicals, Prof. Goren can reveal hidden information about a tablet’s composition without damaging the precious ancient find itself. These x-rays reveal the soil and clay composition of a tablet or artefact, to help determine its precise origin.
But Prof. Goren’s uses x-ray fluorescence (XRF) spectrometry to determine the elemental composition of the tablets or seals. The tool ‘bombards’ the sampling area with X-rays, which – in it’s excitement – will emit fluorescent (or secondary) X-rays. The wavelengths of the released energy and the relative intensity of each frequency emitted – the emission spectrum – is detected by the device, revealing the composition of the clay material. Its elements are identified on the basis of the unique wavelength of their fluorescent X-rays, while concentration of these elements can be estimated from the intensity of the released X-rays.
The tool, he says, can also be applied to coins, ancient plasters, and glass, and can be used on site or in a lab. He plans to make this information widely available to other archaeological researchers.