Micro-PIXE analysis of an Egyptian Papyrus

Identification of the pigments used for the "Book of the Dead"

A-M. B. Olsson1, T. Calligaro2S. Colinart2 , J.C. Dran2N.E.G. Lövestam3B. Moignard2 and J. Salomon2

1University of Göteborg, SE-405 30 Göteborg, Sweden 
2Centre de recherche et de restauration des musées de France, CNRS UMR 171, Palais du Louvre Paris, France 
3Chalmers University of Technology, SE-412 96 Göteborg, Sweden

View of the external microprobe set-up with the papyrus in place

The Papyrus KM 21933 consists of hieroglyphic text ended by a painted vignette. It forms the right end of a “Book of the Dead” from the Theban 19th Dynasty (c.1295- 1186 B.C.). This name is given to religious funerary texts and spells for protection and guidance of the deceased entering the afterlife. Probably discovered in the 1820 ́s, it was acquired in Berlin in 1912 by The Kulturen Museum in Lund, Sweden.

Objectives
1) study the elemental composition of the inks and paints 
2) search for anachronistic pigments that would reveal a forgery 
3) identify undocumented preservation or restoration treatment

Painted part of the papyrus (vignette), showing Ash-au-hat and the goddess Ipet. The location of scanned areas and analysed spots are indicated ( 1:1 scale)

PIXE spectrum of white pigment : Sr and Mg are major constituents

 Experimental set-up

  • PIXE with 3-MeV proton beam, ~0.6 nA
  • external microprobe Ø 50 μm, He atmosphere
  • 0.1μm thick Si3N4 exit window
  • 2 detectors to cover the 0.5-40 keV energy range
  • elemental maps by scanning the papyrus, beam fixed
  • images : 40mmx40mm areas, 200x200 pixels
  • dose monitoring using X-ray signal from exit window
  • MPAWIN multiparameter data acquisition system

Results:

colour material pigment formula observation
red ink hematite Fe2O3 Fe line only
black ink carbon (soot) C attenuation of O K-line
red painting ochre Fe oxide + clay Fe, Al, Si, Ca lines
blue painting egyptian blue CaO.CuO.4SiO2 Cu, Si, Ca lines
white painting huntite Mg3Ca(CO3)4 Mg, Ca lines
white painting celestite SrSO4 Sr, S lines
green painting verdigris (CH3COO)2.Cu Cu line only
yellow painting orpiment As2S3 As, S lines
white grains insecticide ? As2O3 As line only