# Spectroscopic and Microscopic Characterization of Flashed Glasses from Stained Glass Windows
## 3 Results and Discussion
### Chemical Characterization
#### 3.2.2 Laser-Induced Breakdown Spectroscopy
\begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{2}{c}{**Samples**} & \multicolumn{2}{c}{**Elemental Composition as Determined by LIBS**} \\ \hline \multirow{3}{*}{Pink1} & CL & **Si**, B, Mn, **Fe**, **Pb**, Al, Ca, K, **Ba**, Sr, Ti, **Na** \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, K, Ba, Sr, Ti \\ \hline \multirow{3}{*}{Pink2} & CL & **Si**, B, Mg, Al, **Ca**, **Cu**, **Na**, **K**, Fe, Ti \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, K, Ba, Sr, Ti \\ \hline \multirow{3}{*}{Brown1} & CL & **Si**, B, Mg, Al, **Ca**, **Na**, K, Ba, Sr, Ti \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, K, Ba, Ti \\ \hline \multirow{3}{*}{Brown2} & CL & **Si**, B, Fe, Mg, **Ca**, Al, **Cu**, **Na**, K, Ti \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, K, **Ba**, Ti \\ \hline \multirow{3}{*}{Blue1} & CL & **Si**, B, Mg, **Ca**, Al, **Cu**, **Na**, Fe, K, Ba, Ti \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, Fe, K, Ba, Ti \\ \hline \multirow{3}{*}{Blue2} & CL & **Si**, B, **Mg**, **Ca**, **Al**, **Cu**, **Na**, **Co**, K, Ba, Ti \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, K, Ba, Ti \\ \hline \multirow{3}{*}{Blue3} & CL & **Si**, B, **Co**, **Mg**, **Ca**, Al, **Cu**, **Na**, **Ba, Ti, Zn \\ \cline{2-3}  & BG & **Si**, **Mg**, Al, **Ca**, **Na**, **Ba, Ti \\ \hline \multirow{3}{*}{Black} & CL & **Si**, Mg, **Fe**, **Mn**, **Ca**, Al, **Ni**, **Na**, **Co**, **K, Ba, Cr, Sr, Ti \\ \cline{2-3}  & BG & **Si**, Mg, Al, **Ca**, **Na**, **K**, Ti \\ \hline \multirow{3}{*}{Green1} & CL & **Si**, B, Mg, Mn, **Ca**, **Al**, **Pb**, **Cr**, **Ti**, **Cu**, **Co**, **K**, **Na** \\ \cline{2-3}  & BG & **Si**, **Mg**, Al, **Ca**, **Na**, **K**, Ti \\ \hline \multirow{3}{*}{Green2} & CL & **Si**, B, **Fe**, Cr, Mg, Al, **Ca**, **Cu**, **Co**, **K**, **Ba**, Sr, **Na** \\ \cline{2-3}  & BG & **Si**, **Mg**, Al, **Ca**, **Na**, **Ba**, **Sr, Ti \\ \hline \multirow{3}{*}{Green3} & CL & **Si**, B, Mn, **Cr**, **Mg**, **Pb**, Al, **Ca**, **Cu**, **Co**, **Ba**, **Na** \\ \cline{2-3}  & BG & **Si**, **Mg**, Al, **Ca**, **Na**, **Ti** \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Elemental composition of base glass and colored layers of flashed glasses as determined by LIBS. The main components and possible chromophores are indicated in bold black and bold red, respectively. BS: Base glass, CL: Colored layer. deformations of the base glass substrate during the production of the flashed glass. The presence of Fe lines, and the minor contribution of Mn lines, indicate the presence of the chromophores [45] responsible for the slight pink coloration of these colored layers. The rest of the components (Si, Al, Ca, K, Ba, Sr, and Ti) are attributed to impurities, stabilizer agents, and elements used in the fabrication of the glass. Figure 5b shows the LIB spectrum derived from the Pink2 sample revealing a qualitatively similar composition than that of the Pink1 sample, except for the additional presence of Cu chromophore, as determined also by FESEM-EDS. The contribution of Fe to the dark pink coloration of the Pink2 sample is revealed to be minor. Emission lines assigned to Si, Ca, Al, K, and Na correspond to the main glass components, while other emissions due to Ti, Mg, and Sn are attributed to stabilizing agents and impurities of the raw materials. The LIB spectrum from the colored layer of the Brown1 sample (Figure 5c) displays emission lines of Fe, Mn, and Cr corresponding to the chromophores. Other lines in the spectrum are attributed to Si, B, Mg, Ca, Al, K, Ba, Sr, Ti, and Na. The composition of the colored layer from sample Brown2, displayed in Figure 5d, differs from that of sample Brown1, as in the latter, Cu is the main chromophore with little Fe contribution. Sr and Ba lines are not observed for the Brown2 sample. The LIB spectra acquired on the colored layers of Blue1, Blue2, and Blue3 samples (Figure 5e,f,n) are qualitatively similar with the exception of the lines associated with their chromophores.