## 3 Results
### Bright Red, Red, Purple Red, Light Red/Orange and Yellow
The presence of cinnabar, hypothesised on the basis of the elemental analysis, was then confirmed by the results of Raman spectroscopy; the spectra of samples 1 (Figure 5e) and 3 (Figure 5d) have in fact its unmistakable features characterised by very strong bands at 253, 284 (sh) and 343 cm\({}^{-1}\)[29]; the weak peak at 1086 cm\({}^{-1}\) is due to calcite [30]. Figure 4: ATR-FTIR spectra of: (**a**) sample 1; (**b**) sample 2; (**c**) sample 3; (**d**) sample 4. In sample 2 (Figure 4b) the peaks at 1032, 1009, 913, 533 and 468 cm\({}^{-1}\) are once again attributable to red ochre containing kaolinite [23; 24; 25; 26; 27; 30; 31; 32]. Raman analysis confirmed the outcomes of FTIR analysis on the previously discussed samples; the spectra of red ochre characterised by peaks at 291, 406 and 605 cm\({}^{-1}\) were obtained (Figure 5a,b) [33]. Additionally, in this case, the peak at 1086 cm\({}^{-1}\) was due to calcite, whereas the band at 147 cm\({}^{-1}\) can be ascribed to lead oxide in its tetragonal form known as litharge [34]. The weak peak at 253 cm\({}^{-1}\) could be associated with the presence of a low percentage of cinnabar, even though mercury does not appear in the EDS spectrum; we underline that the Raman spectrum in Figure 5b was acquired by means of a punctual analysis performed by micro-Raman (whereas no spot analysis was performed with SEM-EDS on that sample), which implies that cinnabar was not uniformly distributed on the painting layer; moreover, the relative intensities of EDS peaks associated with Hg for samples 1 and 3, where cinnabar has been clearly detected, are quite low, so it seems plausible that the Hg signals were not detectable through SEM-EDS in sample 2. The small concentration of cinnabar in this sample shows that the painter apparently mixed different minerals to obtain the desired red hue. As already seen in samples 1 and 3, red ochre is frequently used as a layer beyond the final cinnabar coat but is rather unusual as a mixing element in a red ochre layer and is therefore a bit surprising. The spectrum reported in Figure 4d for sample 4 shows a trend that is rather more associable with Fe\({}_{2}\)O\({}_{3}\) (haematite) than red ochre, because of the wavenumber and especially the shape of the bands at 540 and 472 cm\({}^{-1}\)[26; 27; 32]; the broad bands at 1090 and 794 cm\({}^{-1}\) are once again ascribable to silicate minerals, but not, as is typical in ochres, to kaolinite, giving strength to the hypothesis that pure haematite was present in this sample. It must be remarked that in this case Raman spectroscopy was very helpful, since the spectrum shown in Figure 5c is practically identical to the one of haematite, showing peaks at 223, 288, 404, 490 and 604 cm\({}^{-1}\)[30]; that definitively made it possible to assign the nature of the purple red pigment in sample 4. ATR-FTIR spectra shown in Figure 6a,b refer respectively to light red/orange sample 5 and to yellow sample 6. Along with the strong bands at 873 and 712 cm\({}^{-1}\) due to calcite and those at 1032, 1009 cm\({}^{-1}\) of silica [24; 27], there are main peaks of yellow ochre at 913, 797, 532 and 468 cm\({}^{-1}\)[26]. Raman analysis confirmed the presence of yellow ochre in sample 6 (Figure 7c), particularly because of the peak at 391 cm\({}^{-1}\) attributed to goethite [33], whereas in sample 5 (Figure 7b) the peak at 405 cm\({}^{-1}\) is attributable to red ochre [25], as in the already discussed sample 2 (included in Figure 7a for comparison). It must be noted that the micro-Raman analysis performed on sample 5 (Figure 7b), gave the strong band at 143 cm\({}^{-1}\) of lead oxide, probably present in this case in its yellow orthorhombic form called massicot [35], and the peak at 463 cm\({}^{-1}\) of quartz [26].