Archaeometry is the science of archaeology, using analytic chemistry, spectroscopy, (bio) organic chemistry, electrochemistry, physics, conservation science, museology, anthropology, history, history of art and archaeology. In other words all the post-Indiana Jones stuff.
The analysis of precious artefacts or art works which cannot be taken apart or damaged or even moved and micro samples of pottery and paint flakes are being undertaken by scientists using several non-invasive methods.
In 2007, Professor Vandenabeele worked on the Menna Tomb Project. Menna was a high official who served as an overseer of the Cadastral surveys during the reigns of Tuthmosis IV and Amenhotem III between 1419 - 1370 BC. His tomb at Thebes is one of the finest painted, non-Royal Egyptian tombs open to the public and the paintings decorating the walls are marvellous examples of what Egyptians could do with pigments and plaster.
The research team of scientists involved in the archeaometry phase used visual analysis techniques of colorimetry (visible, ultra-violet and near infra-red) x-ray fluorescence (XRF) and RAMAN spectroscopy. The aim was to provide a complete analysis of the organic and inorganic materials, that is, the paint pigments, varnishes, binders and plaster in the tomb. The results would show not only the ancient materials but later repairs by conservators that may be degrading the paintings.
This is the XRF machine built especially for this project. After a visual examination of the painting, points were selected for study and analysis. As all archaeometric processes work by using the effect of light wave lengths converted to spectral troughs and peaks, nothing touches the painted walls so pigments or matrix remain intact.
The x-ray fluorescence here has identified the elemental components of the sample of yellow and it's inorganic concentration. The highest peak is As (Arsenic) and the next is Ca (Calcium) with smaller concentrations of Fe(Iron) Sr (Strontium) which indicates the pigment is almost pure orpiment, an arsenic sesquisulphide (As2S3). ( don't ask what sesquisulphide is or you'll be made to google it yourself)
Preliminary findings show that the Egyptian artists worked with combinations of pigments in different mixtures, either mixed together and then applied to the wall, or laid on in washes to create transparency.
And in true Lord Hughes style, I'll be posting about the conservation of the tomb next, with photos.