Figure 3
XRF cartography of elements present on a little zone of the image. With elements, we can identify the pigments used for the illumination. The analysis zone corresponds to Saint Peter's head: copper (a) in blue pigments (azurite); mercury (b) in red pigments (cinnabar); sulfur (c) associated with mercury for the red pigments (cinnabar) and with arsenic (d) for the yellow one (orpiment); lead (e) in white pigments composed of lead white; Gold (f) is present in the gilding zone, in the background of the scene.