*3.4. Green Pigments*

All the reflectance spectra of the green hues were bell-shaped in the visible region of the spectrum, with a reflectance maximum in the range 520–575 nm. The absorption band in these spectra systematically occurred at ca. 750 nm (Figure 4a), which is not fully compatible with the feature of verdigris (720 nm) nor with that of malachite (800 nm) [24].

**Figure 4.** (**a**) selected FORS spectra representative of the different green shades. The green lines are spectra collected from green areas within the miniatures, the top yellow-green lines are spectra collected from yellow-green areas within the miniatures. (**b**) Bivariate plot for XRF signals of copper (Kα line, 8.05 keV) vs. zinc (Kα line, 8.64 keV) recorded from green areas in the miniatures; the regression line with coefficient R is indicated.

The XRF analysis detected strong copper signals, as well as weak zinc signals, that showed a linear trend when plotted on a graph (Figure 4b). Zinc ores are described as being contaminants of copper ores [21], therefore this relationship would suggest the use of a natural copper compound.

Unfortunately, with the configuration used, the micro-Raman equipment did not allow us to gain molecular information from the green pigment present and so the actual nature of the pigment remained unknown. A consideration of the features of the FORS spectra and a comparison with those obtained on other coeval *Book of Hours* manuscripts produced in the same area [25,26] suggest the use of a copper sulphate, such as brochantite or antlerite, as the green pigments. To support this tentative identification, the presence of S was suggested by the XRF spectrum, though again, as in the case of ultramarine blue, it could not be definitely confirmed due to the proximity of the S Kα line at 2.31 keV with the Pb Mα line at 2.34 keV.

The spectral range of the reflected light (see the two top spectra in Figure 4a with reflection maxima shifted towards NIR) determines the different shades (green to yellowgreen) observed among the painted green areas. These shades were obtained by mixing a green and a yellow pigment, as was evident from observations of the green areas under the optical microscope (Figure 5).

In such yellow-green areas, significant tin and lead signals were also detected. Moreover, an evident correlation emerged among the XRF signals for tin and lead (not shown), and this strongly suggests the use of lead-tin yellow to brighten the colour. The presence of lead-tin yellow type I which was also used as pure yellow pigment (see Section 3.9), was also confirmed by micro-Raman analysis. The use of lead-tin yellow to modify the tonality of green pigments has already been noted in other works [25,26].

**Figure 5.** Micro-photography (80×) of yellow-green meadows in the background of Saint Elisabeth and the Virgin on f. 15r (*Visitation*, Figure 1b): green and yellow particles are clearly visible.
