Seite - 219 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

Hofmann, Rabitsch, Malissa, Aceto, Uhlir, Griesser, Calà, Agostino, Fenoglio 219 The grey areas are mixtures of lead white with carbon black. Highlights were painted in lead white. Shades are mixtures of indigo and lead white. The contours were painted in black. Painter A used a variety of greys. Frequent blue-grey tones are a mixture of ultra- marine blue, indigo and lead white. Indigo is confirmed by FORS, ultramarine blue and lead white by XRF. Raman spectroscopy of a loose grey colour particle indicates orpiment, indigo, ultramarine blue and red lead. The black is probably mostly carbon black. This can be assumed using FORS, where carbon-based pigments show 0 % reflectance. XRF spectra of black areas on the ark on folio 2 (Fig. 18) indicate high intensities of iron (Fe) and silicon (Si), low intensities of aluminium (Al) and titanium (Ti) with significant traces of copper (Cu), zinc (Zn) and mercury (Hg). Based on the information gained by µ-XRF analysis a clear identification of the used material is not possible. The intensive signals of iron (Fe) can be assigned to an iron gall ink, an earth pigment or possibly to iron oxide black. The Raman spectroscopy of a loose black particle from the ark on folio 2 indicated carbon black mixed with a small amount of iron gall ink and indigo. The use of iron gall ink explains the presence of the trace elements copper and zinc. The origin of mercury stays unclear. A possible explana- tion is either that it is a component of the ink or that it is present due to blurring from neighbouring regions. Painter A used mixtures of carbon black and iron gall ink to paint different shades in the large black areas of the ark on folio 2 (Fig. 3). In this miniature of the flood, the rain was painted with indigo on top of the other layers. Visually it is difficult to differentiate the various mixtures of carbon black with other pigments like dark ochre, Fig. 18: XRF spectra of black areas on folio 2, page 3 (MP2_3 and MP2_6, black and dark grey) and 4 (MP2_11, light grey). A spectrum of the parchment of folio 1 (MP1_3, brown) shows the back- ground signal detected. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0