Non destructive characterization by FOM and ESEM-EDX of ancient glass objects from the Aegean with an approach of the manufacturing technique

Abstract

The aim of the present work is the application of the non destructive techniques of fiber optics microscopy (FOM) and environmental scanning electron microscopy with energy dispersive x-ray analysis (ESEM-EDX), for the characterization of a group of decorated colored glass objects, with relation to the manufacturing technique. All the glasses are in the form of small fragments, which have come to light at archaeological excavations in the area of Dodecanese in Greece and are dated at a period between the fifth and fourth century bc. Today they belong to the National Archaeological Museum of Athens. The great antiquity of the glass fragments did not allow any sampling or even micro-sampling. Thus FOM and ESEM-EDX methods were used for their microscopic examination and elemental compositional analysis. The compositional data obtained led to significant results on the level of the adopted glass technology, suggesting an identification of the coloring agents used for the production of the glass objects colorations: Pb and Sb are indicated as responsible colorants for the opaque yellow decorations, while only Sb is present in the white ones. Green glasses exhibit high levels of Fe. The dark grey coloration is attributed to Ni content, while Fe along with Mn and Ni elements are present in black glasses. Co is found to be the responsible colorant for blue glasses. In this work, the results obtained from the microscopic examination provided substantial information on the level of the employed glass manufacturing technique used, allowing us to assume that the core-forming was the main technique used for the production of the glass artifacts.