## 3 Results and Discussion
### SEM-EDS Analysis
#### 3.3.2 Bronze Samples  
Sample 13. The investigations are mainly focused on one area, which seems to have impurities (Figure 10 on the left). The morphology is homogenous and completely different from the other two samples previously described. However, different kinds of inclusions infer differences in color on the surface. The most abundant oxide is CuO which varies from 20.59 to 94.53 (Table 3), depending on the analyzed areas. SnO is also present with quite high values (from 1.73 up to 55.02). It was interesting to note that in areas 11 and 13 where CuO is low, SnO has high values and vice versa. Fe2O3 shows low concentration, followed by Al2O3. Si, Mg, P, S, Cl and K oxides have concentrations close to the detection limit of the instrument. Lead occurs in very low amounts and not in all spectra. In this case, Na and Zn oxides are not detected. Sample 16. Figure 11 shows the scheme of the analyzed areas and the photo imaging. The morphology appears homogenous in most of the sample, as for sample 13. The imaging of detail 49 (in light blue) was interesting, in which differences in color on the surface of the samples are visible, probably due to the presence of different kinds of inclusions. CuO is the major oxide, ranging from 26.42 to 93.94. SnO is also present with high content, especially in area 43, where it reaches the highest values (33.58). On the contrary, CuO has the lowest value (26.42 respect to 93.94 and 91.08 of the other area analyzed), as for sample 13. Always in area 43, PbO occurs with high values (3.66) and high values of Fe2O3 (21.70), instead, both had lower values in the other two areas. Na, Mg, Al, P, S, Cl and also Si and Ca oxides have concentrations close to the detection limit of the instrument. K and Zn oxides were not detected. Figure 10: Schematic of the areas investigated by SEM-EDS for sample 13. Area 1 was analyzed in detail in point 3 (colored in white). Area 5, colored in light blue, presented a layer of green patina (detail 9) covered by a rust-colored layer (detail 7). Area 11 represents the white patina and area 13 the orange one (colored in red). SEM images are related to detail 3 (in white), detail 7 (in light blue), detail 11 (in red). Sample 20. This fragment was extensively investigated, starting from the area on the right including the green patina and an underlying orange from which we could see the underlying layer (Figure 12). SEM images showed a homogenous morphology of the sample. CuO is the most abundant oxide (Table 3) with a maximum value of 97.67, but in some areas analyzed the presence of CuO was lower (9.43 or 12.53). In the areas where low values of CuO occur, high values of SnO are observed (52.08 and 57.81, respectively). Fe\({}_{2}\)O\({}_{3}\) was also analyzed in all the areas, showing a heterogeneous distribution. Na, Mg, P, S, CI, K and Ca oxides have concentrations close to the detection limit of the instrument. Si and Al oxides occur in very low values content, excluding the results of area 29. Zn was not detected. Figure 11: Schematic of the areas investigated by SEM-EDS for sample 16. The area 43, colored in white, presented a green patina from which a rust-colored area can be glimpsed. On the top, the azurite-rich area (area 47) and its detail (detail 49) was both colored light blue. SEM image is related to detail 49 (in light blue). Figure 12: Schematic of the areas investigated by SEM-EDS for sample 20. Area 15, colored in blue, presented the green patina and an underlying orange and detail 17, colored in light blue, was the rust-colored area. Area 19, colored in yellow, included a green patina and a white patina which was then further investigated in the detail 21. Area 29, colored in white, presented a thick green patina with a pitted appearance. Finally, a thin layer of copper color (area 23, colored in black) and two different details 25 and 27. SEM images are related to detail 17 (in blue), detail 21 (in yellow) and detail 27 (in black). Sample 25. Figure 13 shows the scheme of the analyzed sample.