## 3 Results
### Bright Red, Red, Purple Red, Light Red/Orange and Yellow
As in the case of sample 2, sample 5's micro-Raman spectroscopy revealed a composition that was slightly different from the one evinced by SEM-EDS measurements, as no lead was found; however, it must be stressed that no punctual SEM-EDS analyses were performed on sample 5, because none of the BSE images indicated the presence of any heavy metal on it. Since that sample had quite large dimensions, it seems probable that the measurements were not performed exactly on the same area by Raman and SEM-EDS techniques. The ubiquitous peak at 710 cm\({}^{-1}\) belongs to calcite, whose presence was even confirmed by the peak at 1086 cm\({}^{-1}\) (not included in the figure). Finally, the peak at 284 cm\({}^{-1}\) achieved from each measurements presented in Figure 6, could be most likely assigned to calcite [30], but that is not to exclude that it might be the result of the superimposition of that band of calcite with the one in the 290-300 cm\({}^{-1}\) range of red and yellow earth spectra [25; 26], so in this case, it was not that diagnostic. Summing up the results of vibrational spectra analysis, it can be stated that there was yellow ochre on sample 6. The light red/orange hue of sample 5 was instead probably intentionally obtained either as the overlapping of yellow and red painting or as a mixture of pigments with different yellow and red shades; more precisely, yellow ochre, red ochre and massicot were employed in this case [36]. Finally, on red, light red/orange and yellow samples, the feasibility of visible reflectance analysis was evaluated. In Figure 8a the reflectance spectra of samples 1 (bright red), 4 (purple red), 5 (light red/orange) and 6 (yellow) are shown. Figure 6: ATR-FTIR spectra of: (**a**) light red-orange sample 5; (**b**) yellow sample 6. The reflectance spectrum of sample 1 (the cinnabar-based sample) exhibited the typical semiconductor sigmoidal shape, characterised by a drastic rise around the inflexion point positioned in this case at 600 nm [37]. The features of red sample 4 (the haematite-based one) were instead mainly characterised by a positive slope at 590 nm, whereas a second positive slope is evident at around 700 nm. That shape matches what it is reported in the literature for red iron-based pigments [37; 38; 39]. As regards the yellow sample 6, it showed a profile that appeared very similar to that of the red sample, but in its case, the most pronounced slope stands at 540 nm; two absorbance bands at about 100 nm are also visible. The red and green bands are visible in the same figure, but in the same figure, the red and green bands are visible in the same figure. Figure 8: (**a**) Visible reflectance spectra of samples 1, 4, 5 and 6; (**b**) first derivatives of the spectra presented in (**a**). Figure 7: Raman spectra of (**a**) red sample 2 (\(\omega_{\text{exc}}\) = 1064 nm); (**b**) light red/orange sample 5 (\(\lambda_{\text{exc}}\) = 785 nm); (**c**) yellow sample 6 (\(\omega_{\text{exc}}\) = 1064 nm). 485 and 640 nm (readable as minima in the spectrum) were also detected. Once more the spectral trend resulting from the measurements here discussed conforms to the spectra of iron-based yellow pigments found in the literature [37; 38; 39]. Actually, the spectrum of sample 5 (that basically resulted in a red and yellow overlapped painting) showed a trend quite similar to that obtained from the iron-based pigments; however, in this case, the rapid slope is positioned almost between the red and the yellow samples, namely, at about 575 nm; no trace of massict was revealed by visible reflectance measurements on sample 5. The precise determination of the point of flex for each spectrum was performed by reading the maximum of the corresponding first derivative curve (Figure 8b). All those observations are perfectly in accordance both with the literature [37; 38; 39] and with the previously discussed results concerning red and yellow pigments.