## 3 Results and Discussion
### Laboratory EPMA-EDS Results
Note: for the sample S10 (**b**) the EDS spectrum reflects the elemental composition at the point analysis marked as 01.  
reddish coloration, such as the red lead (i.e., minium), and white color, such as the white lead. As far as the detection of chemical elements attributable to earths (Si, Al, Mg, K, Fe, Na, Ti) is concerned, another guess is the use of a mixture made of white lead added to red lead and green earth, all compounds used by the artist for flesh undertones. In fact, the green earths neutralized the effect of the pinks and reds of the flesh colors. Only S23, from a chemical point of view, slightly differs from all others due to the additional detection by EDS of Hg and S, suggesting the presence of vermilion. The sample S23 was in fact taken from the face of the angel, at the height of the cheek. The addition of a Hg-based red was likely intentional to make cheek tones more reddish. As for the samples with yellowish tonalities (S13, S24, S26, S27), the EDS spectra reveal high amounts of Pb followed by Sb and smaller amounts of Si, Ca, Na, K, Al, Mg, Cl, Fe, S and Ti. The detection of high Pb contents, accompanied by Sb, pointed to possible use of a lead-based pigment, presumably a lead-antimony yellow (\"Naples yellow\"). The use of such a yellow pigment is in agreement with most used yellow shades in [PERSON]'s palette [8; 10; 12]. Furthermore, traces of mercury and sulfur were also detected in S24. In fact, the S24 sample taken from the angel's hair shows yellow-gold tones, which suggests that the artist has mixed yellow pigment with a red one to obtain more golden shades of yellow. The EDS elemental analysis performed on green samples (S4, S5, S8, S9) led us to hypothesize a probable use of green earth as a mixture of aluminosilicate minerals (i.e., hydrous alumino-silicate of Mg, Fe and K), where the green color of the clays is caused by the presence of green Fe-containing minerals belonging to the group of clay micas (i.e., celadonite or glaucomaite) [10]. Obviously, it is evident that EDS results cannot complete the identification of such components and the contribution of vibrational spectroscopy techniques could be crucial for their identification. Also the sample S9, with yellowish green hue, shows similar chemical composition with respect to previous samples, further suggesting that although green has warmer yellowish tones, chemical elements detected still imply the use of green earths as a pigment. This is in agreement with the literature, according to which green earth colors used in paint range from neutral yellow-green to pale greenish-gray to dark matte olive green [15; 16; 17]. Going on, a comparable elemental composition, mainly based on Pb, Ca, Si, Al, Mg, Na, Fe, K, S, Cl and Ti, can be observed for blackish (S11, S16) and grayish (S12, S14, S17, S18) samples. However, these elements are not sufficient to hypothesize the use of specific pigmenting substances, testifying to a similar method used by [PERSON] for these shades. The major difference is in the detection of Pb, which exhibits a higher concentration in samples with greyish tones. Therefore, it is possible to assume the use of a white lead to blend the blacker colors. The brownish sample S20 shows high concentrations of Ca and Pb followed by Al, Si, Mg, and Fe, and low concentrations of Mn, P, K, Na, Ti, leading to the hypothesis that the artist used natural earth and others pigments for the browns, and probably a Sienna [6; 9; 18], a pigment made from clay, mainly composed of iron oxide and manganese oxide, and other minerals common in soils. Given the relevant Pb content, partly attributable to the preparatory layers, the addition of white lead to soften the brownish tones has not to be excluded. Finally, regarding the two samples with blue shades (S15, S21), a different chemical composition was detected. According to EDS data, sample S15 could be a malt, a blue potash glass pigment where the blue color is due to the presence of Co [19; 20; 21; 22].