A bit off-topic but the technique looks as though it will be applicable to Amarna period tablets too.
Unfortunately, when ancient kings sent letters to each other, their post offices didn't record the sender' return address. It takes quite a bit of super-sleuthing by today's archaeologists to determine the geographical origin of this correspondence - which can reveal a great deal about ancient rulers and civilizations.
Now, by adapting an off-the-shelf portable x-ray lab tool that analyzes the composition of chemicals, Prof. Yuval Goren of Tel Aviv University's Department of Archaeology and Ancient Near Eastern Civilizations 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 process, based on x-ray fluorescence (XRF) spectrometry, can go much further. Over the years, he has collected extensive data through physical "destructive" sampling of artefacts. By comparing this data to readouts produced by the XRF device, he's built a table of results so that he can now scan a tablet - touching the surface of it gently with the machine - and immediately assess its clay type and the geographical origin of its minerals.