Vitreous finds from the Iron Age archaeological complex at Bilsk (Ukraine) as evidence of trade by land and sea

The Bilsk archaeological complex comprises the remains of many structures associated with an impressive Iron Age fortified site and extends over a vast area in central-east Ukraine. Its importance is marked by the presence of apparently imported objects, including some vitreous ones (represented mainly by glass and faience beads), which provide researchers with materials for studying past trade in the area. A representative set of vitreous fragments was subjected to an analytical study with several instrumental techniques (namely: scanning electron microscopy coupled with energy dispersive spectrometry, laser ablation inductively coupled plasma mass spectrometry, micro-Raman spectroscopy and micro-X-ray diffraction) in order to characterise the beads on compositional basis. The complementary data from different techniques revealed a complex picture for the raw materials, identifying several sources of silica and, consequently, several production centres for the items included in the analysed set. This information in turn led to a better understanding of the trade networks that operated in the region between the 7th and 4th century BCE. Colouring and opacifying agents are also discussed.