Simulation of X-ray fluorescence spectra from a medieval parchment with red ink writing

Synchrotron X-ray fluorescence spectra were simulated using the Geant4 software package to quantify the elemental composition of a red ink contained in a medieval parchment. From comparison of the spectra emitted from a blank spot and a spot with the writing we have found that the ink contains significant amounts of lead and mercury. This allowed us to hypothesize that the ink was based on a natural mineral pigment minium with an admixture of cinnabar.