# The Archaeometallurgical Evaluation of Three Bronze Socketed Axes, Discovered in Eastern Romania
## 3 Results and Discussions  
From the microphotographs obtained by OM for the representative areas, each of the three analyzed socketed axes show interesting characteristics in terms of corrosion and use. Specifically, socketed axe A has a relatively uniform, thin layer of corrosion on the surface, completely covering the metal core (Figure 3a). Near the blade, in the outer layer, there were identified traces of deep scratches (Figure 3b), attributed to the use of the item before deposition, and at the interface of the metal core were found chemical compounds resulting from the corrosion processes occurring on the base alloy, namely, copper oxides--red--and the basic copper carbonates--green (Figure 3c). Socketed axe B presents a corrosion layer distributed very heterogeneously over the entire surface of the item (Figure 3d), in which deposits of the basic carbonates and copper oxides were randomly located on the micro-zones in the form of crusts (Figure 3e), and at the interface with the metal core were found thin layers of copper oxides, also disposed unevenly (Figure 3f). Socketed axe C presents a discontinuous, thin layer of corrosion with unevenly arranged deposits of oxides (cuprite/tenorite), chlorides (nantochite) and copper basic carbonates (malachite/azurite), cassiterite and silver veins, unevenly distributed in the form of crusts or thin layers (Figure 3g-i). SEM-EDX analyses were performed on both the surface corrosion layer and the stratigraphic structure at the interface with the base alloy to highlight the correlation between the chemical composition of the artifact, the nature of the corrosion products and the elements taken from the soil (contamination). From the SEM micrographs of the corrosion layer of socketed axe A (Figure 4S1-1, S1-2 and S1-3) was identified a structure with a non-homogeneous distribution, characterized by the presence of cracks, microcavities and microphases differentiated as superficial structures in the form of irregularly shaped granules. Figure 3: OM images of the three representative areas of the surface of the socketed axes: (**a**) uniformity of the corrosion layer for axe A; (**b**) scratches caused by use before deposition for axe A; (**c**) the oxides and basic carbonates of copper for axe A; (**d**) disposal of the corrosion products in the patina for axe B; (**e**) the basic carbonates and copper oxides for axe B; (**f**) copper oxides for axe B; (**g–i**) the corrosion layer with the disposal of the chemical compounds of the patina for axe C.  
The EDX analyses of these surfaces identified the chemical elements corresponding to the basic alloy (Cu and Sn) and the ore impurities (Pb and Fe), as well as the elements of the corrosion products (C, O and Cl) and of the contamination from the soil, such as Si, Al, Mg, P and S (Table 1). This composition shows that the artifact has undergone corrosion and segregation processes under the influence of an environment with fluctuating humidity and temperature, rich in oxygen and carbon dioxide, in the presence of alkaline and alkaline-earth cations, phosphates, carbonates, aluminosilicates and silicon dioxide (quartz micro-crystallites). The SEM micrographs of the corrosion layer of socketed axe B, also performed on three representative areas, are shown in Figure 4(S2-1,S2-2,S2-3). Through the analyses, the surface structures, with a non-homogeneous granulometric distribution of the corrosion crusts and metallic micro-phases with uneven geometric profiles, can be observed. The elemental EDX analyzes of the corrosion layer of socketed axe B, performed on the three areas (S2-1, S2-2 and S2-3), corresponding to the SEM micrographs in Figure 4, is shown in Table 1.  
Thus, in samples S2-1 and S2-3 were highlighted the chemical elements corresponding to the basic alloy (Cu and Sn), and the micro-elements from the ore were based on Ni, Pb and Fe.