## 3 Results and Discussion
### Pigments
#### 3.2.1 Red, Pink and Orange  
The Raman spectrum of the red pictorial film shows the characteristic bands of hematite, \(\alpha\)-Fe\({}_{2}\)O\({}_{3}\) (bands at 224, 290, 413, 500 and 613 cm\({}^{-1}\)) and calcite (bands at 713 and 1086 cm\({}^{-1}\)), indicating the use of a hematite-based pigment. Iron-oxide pigments have been widely used since prehistoric times because of their extreme stability and high coloring capacity. Their use was also recorded during the Middle Ages, and their presence was attested in other Calabrian Medieval wall paintings [19; 20].  
In order to compare the data obtained from Raman Spectroscopy, a chemical investigation of the pictorial film was performed by SEM-EDS.  
The results of the compositional micro-analysis of the reddish pictorial layer on sample S_1, performed by the EDS probe combined with SEM, are coherent with those of Raman spectroscopy. EDS investigations revealed the presence of high iron contents and a moderate percentage of silicon and aluminum, which can be attributed to the presence of red ochre pigments, confirming the results of Raman spectroscopy [32; 33] (Figure 9, Table 4).  
Bands at 226, 286 (hematite) and 1086 cm\({}^{-1}\) (calcite) were detected for the pinkish colored areas of the painting as well. Based on the foregoing, the pink tone was probably obtained by mixing the hematite with a white calcite-based pigment, such as bianco San Giovanni. As a matter of fact, bianco San Giovanni pigment, according to the procedure described by [PERSON], was generally prepared by drying lime and then reducing the newly-formed calcium carbonate to powder [34; 35]. On the other hand, it can not be ruled out that the hematite was lightened by adding a significant amount of pure lim  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample ID** & **Measurement Point** & **Chemical Element by EDS** & **Pigment** \\ \hline S\_1 & Red particles within the pictorial layer & **Fe, Ca, Al, Si, Cl, Mg, S** & Red ochre \\ S\_4 & Black inclusions within the pictorial layer & **C, Ca** (Na, Al, Si, Mg, S, K, Cl) & Carbon black \\ \hline \hline \end{tabular}
\end{table}
Table 4: EDS chemical analyses detected for painted layers of samples S_1 and S_4. Notes: more abundant elements in bold; minor elements in brackets.  
Figure 9: EDS spectrum punctually acquired on the red pictorial layer (sample S_2) (highlighted by the red square) and related SEM image.  
The Raman analysis for the orange pictorial film exhibited bands at 279, 713 and 1088 cm\({}^{-1}\), again suggestive of calcite, and bands at 248, 301, 528 cm\({}^{-1}\), which can be assigned to iron (III) hydrous oxide, \(\alpha\)-FeOOH, also known as \"goethite\". The Raman spectrum of goethite exhibits bands at 245 cm\({}^{-1}\), 299 cm\({}^{-1}\), 387 cm\({}^{-1}\), 480 cm\({}^{-1}\) and 550 cm\({}^{-1}\). The band at 245 cm\({}^{-1}\) is due to the symmetric stretching of Fe-O bonds, bands at 480 and 550 cm\({}^{-1}\) to asymmetric stretching of Fe-OH bonds, the band at 299 cm\({}^{-1}\) is assigned to the symmetric bending of Fe-OH bonds and that at 387 cm\({}^{-1}\) to the symmetric stretching of Fe-O-Fe/-OH bonds. In our case, the bands at 245 and 389 cm\({}^{-1}\) are consistent with those reported in the literature [36].