Analysis of prehistoric glass from Slovenia

A series of prehistoric glass beads and other glass items (bracelets, brooches with glass overlays, spindles, amphoriskos) from Slovenia was analyzed by a combined PIXE-PIGE method. The items were selected from seven late prehistoric horizons spanning uniformly from the 11th c. BCE to 2nd and 1st c. BCE. Totally 74 measurements on 60 objects were made on bulk material and on some ornamental bands. The beads of the Late Bronze Age (LBA) were made of mixed alkalis that we estimate to be plant ash origin (precipitated potash and non-precipitated ash of halophytic plants). According to the type of pigmentation (Co or Cu) there are hints, either direct or indirect, to connect particular beads with Egyptian workshops. Egyptian influence continues well into the Early Iron Age (EIA), until the 5th c. BCE when the low Zr values signalize glass of Levantine origin. Sorting the measured glass by discriminant analysis considering the elements Al, Ti, Mn and Fe we observe grouping of the beads according to historic horizons. This indicates particular beads were made in specific workshops and spread over a large area by exchange and commerce. Local production for traded or recycled glass may be presumed in LBA, as well as in later phases of the EIA, around 5th-4th c., when the beads show a variety of forms.