M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)
Analysis - ZIMMER Károly: Spectrochemical investigation and classification of Hungarian glass finds
Figure 1 shows the concentration distribution of the Ba, S, Si, K and Ca content of a fragment of a glass jug in the longitudinal and transversal directions of the fragment. It can be stated on the basis of the distribution curves that Ba and S have exactly the same run, i. e. the two elements are present in the glass in the form of BaS0 4 . The longitudinal distribution illustrates particularly well that BaS0 4 occurs in higher concentrations in the bulk of the fragment, whereas Si is enriched rather on the surface and close to the surface of the fragment. 9mm trans verzoll S 5 \\ Ba Si £ S w ° c N —Ca 4A if r i —i i i i 1 3 5 7 9 H f 'longitudinal m r i i i i i » » i i « i i » 1 3 5 7 9 11 13 1mm measuring positions Fig.l Concentration distribution of some elements in the glass samples The surface of some glass finds were covered with a "corrosion" layer of varying thickness, which was mostly coloured, had rough, in some cases glassy, in other cases porous structure. The concentration distribution of elements was investigated in the surface coating and in the bulk of these glasses, For instance, in the bulk of one of the glasses, one side of which was covered with a brown layer of 0.4 mm thickness, the concentration distribution of the elements was determined at points 0.2 mm apart. The results are shown in Fig. 2. It can be seen that in the brown coating (points 1 and 2) Fe, Mn, Cu and CI are present in higher whereas Si, Al, K and Ca are present in lower concentrations than in the bulk of the glass. Conœrning Na, no such statement can be made. The significant fluctuation of the concentration of elements in the glass fragments, and in part the monotonous (unidirectional) change of concentrations can be attributed to the primitive technology of glass manufacturing. Depending on the cooling conditions of the glass melt, the bulk or the surface of glass may become enriched in certain elements, as shown in Figs. 1 and 2. The other reason for monotonous concentration changes is the lasting contact with soil. This may be the reason for +he formation of coating on the glass fragments, depending on the composition of glass and soil, and for the adsorption of ions
