Page - 212 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

212 The miniatures of the Vienna Genesis: colour identification and painters’ palettes darkening of red lead like on folio 5, page 10 (Fig. 9). The darkening of red lead is an oxi- dation process, which can be caused by high levels of sulphur in the environment or by the transformation of Pb3O4 to black PbO2. On some occasions painter A used a mixture Fig. 4: XRF spectrum of a green area (MP8_5) on folio 8, page 15. For comparison a spectrum of blank parchment of folio 6 (MP6_5) shows the background signal detected. Fig. 5: FORS spectra of green pigments and mixtures: indigo/orpiment, azurite/orpiment, malachite and green earth. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0