Comparative pigment analysis of six modern Egyptian papyri and an authentic one of the 13th centuryBC by Raman microscopy and other techniques

Six Egyptian papyri, supposedly dating to different periods from the 13th to the 1st centuries BC and brought to London for auction, have been analysed by Raman microscopy in order to try to authenticate them. Complementary studies by scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and polarized light microscopy (PLM) have also been carried out in some cases. The following pigments were detected: phthalocyanine blue, phthalocyanine green, chalk, anatase (white), Prussian blue, a Hansa yellow, ultramarine blue, iron(III) oxide and two β-naphthol reds. Most of the pigments on the papyri were thus recognized to be modern, their syntheses or refinement processes not being known to the ancient Egyptians. The above results have been compared with those obtained from the analysis of an authentic Egyptian papyrus belonging to the Petrie Museum and dating from the 13th century BC. This papyrus had recently been conserved by the British Museum and placed under glass. The Raman study, which was performed without removal of the glass, revealed the presence of pararealgar (yellow), which is a photodegradation product of realgar (red). Carbon and orpiment were also present on this papyrus, and possibly iron(III) oxide, malachite or Egyptian green, and Egyptian blue, but no modern pigments. These results are consistent with the authenticity of this papyrus, and highlight a convenient and effective method by which ancient and modern papyri may be distinguished. Copyright © 2000 John Wiley & Sons, Ltd.