Chemical composition of La Tène glass from Devín castle was set by semi-quantitative spectral analysis. Considering the obtained results, all the analysed samples could be classified into the group of sodium-calcium-siliceous glass. Chemical characteristics reflect the usage of sodium flux in the glass production. Big portions of calcium (Ca) and magnesium (Mg) in the analysed samples are indicating flux obtaining from phytohaline plants fly ash, what is characteristic to Mediterranean region. Hence, the glass melt was imported. The semi-quantitative chemical composition showed particular elements, which were used as dyeing oxides. A final glass colour depended on the dyeing oxide used and the atmosphere in a glass furnace. Cobalt-blue glass colouring was caused by cobalt oxide (CoO), while paler shades were probably obtained by changed CoC concentration and higher contents of Fe2O3, PbO and Sb2O3. Dark purple shades were obtained by adding of manganese (Mn) compounds and by reduction atmosphere. Oxidation atmosphere and adding of compounds containing iron (Fe) and copper (Cu) produced olive-green colouring.
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.