# Study on the Middle Bronze Age Disc-Butted Axe Ornament from Archaeometallurgical Point of View
## 3 Results and Discussions
Thus, the basic alloy, both the hammer and the ornament were depleted during the burial period, by segregating the active metallic elements (from the series of electrochemical activities to the left of the tin) and migrated into the soil under the influence of groundwater. For example: Fe, Zn, Ni etc. which are found in other artifacts obtained from the same ores (derived from the area of the Eastern Carpathians), are not present in these structures. As far as the ornamental layer is concerned (sample S2), the profile of the variation of the concentration of alloying components was studied, as stated, in specific points, considering the surface morphology in compact areas, with ornament, cracks and gaps. Therefore, the central incision areas were studied: left of the incision (S2-1), in the incision canal (S2-2) and right of the incision (S2-3) towards the core of the sample. Three micro-surfaces (S2-A, S2-B and S2-C) were also analysed in the compact plateau area to the right of the second incision, which have different corrosion structures, in terms of uniformity and colour. Table 2 shows the EDX analysis of areas S2-1, S2-2 and S2-3 on the outer surface of the ornamental layer (Figure 4). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Area**} & \multicolumn{5}{c}{**Elemental Composition (wt \%)**} \\  & **Cu** & **Sn** & **As** & **Ni** & **Fe** & **Error** \\ \hline S2-1 & 85.55 & 13.07 & 0.71 & 0.77 & - & 2.56 \\ S2-2 & 87.78 & 10.60 & 0.52 & 0.68 & 0.42 & 2.33 \\ S2-3 & 90.64 & 8.13 & 0.31 & 0.59 & 0.46 & 3.11 \\ S2-4 & 33.02 & 62.27 & 3.71 & - & 1.61 & 1.12 \\ S2-5 & 43.02 & 53.56 & 3.42 & - & - & 1.27 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Elemental chemical composition of the areas on the outer surface of the gilding and in the section of the two edges, the fresh crack and the old cracked incision, respectively. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Area**} & \multicolumn{5}{c}{**Elemental Composition (wt \%)**} \\  & **Cu** & **Sn** & **As** & **Ni** & **Fe** & **Error** \\ \hline S2-1 & 85.55 & 13.07 & 0.71 & 0.77 & - & 2.56 \\ S2-2 & 87.78 & 10.60 & 0.52 & 0.68 & 0.42 & 2.33 \\ S2-3 & 90.64 & 8.13 & 0.31 & 0.59 & 0.46 & 3.11 \\ S2-4 & 33.02 & 62.27 & 3.71 & - & 1.61 & 1.12 \\ S2-5 & 43.02 & 53.56 & 3.42 & - & - & 1.27 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Elemental chemical composition of the base alloy in the three areas of the S1 sample. The S2 sample on the outer surface is much improved in Cu compared to Sn. This explains its shiny malachite green colour and the noble protective patina behaviour of the tin film. It is common knowledge that redox cementation reactions occur at the red-hot Cu alloy interface during thermal gilding using Sn ores. Since the interface is a polyelectrolyte system, the Cu alloy will play the role of cathode, and the tin alloy the role of anode. Thus, the Cu\({}^{+,2+}\) oxide or sulphide films on the surface of the ungilded axe are, after gilding, reduced to Cu0, following the interaction with the active metals (Zn, Fe, etc.) in the tin film alloy. It segregates together with the cations of the active metals (Zn\({}^{2+}\), Fe\({}^{2+}\), etc.) in the tin layer towards its surface. Thus, following the processes of dissolution in the melt by segregation in the porous structure depleted in active metals, the cations of active metals drive the precipitated microstructures by Cu(0) cementation to the gilded surface, where, under the influence of hydroxide and carbonate ions, they pass into malachite. By comparing the three selected areas, one may notice that the S2-3 sample in the middle has the highest Cu concentration, compared to the one in the ornament incision (S2-2) and the one on the edge (S2-1). However, the Sn and As concentration varies inversely, while Ni and Fe have different variations, except for Fe, which is absent in the edge area (S2-1) due to the processes of electrochemical segregation and dissolution in aqueous medium with migration into the soil.