X-ray fluorescence spectroscopy is a non-destructive technique employed for elemental analysis of a wide range of materials. Its advantages are especially valued in archaeometry, where portable instruments are available. Considering ancient glass, such instruments allow for the detection of some major, minor, and trace elements linked to the deliberate addition of specific components or to impurities in the raw materials of the glass batch. Besides some undoubted advantages, portable XRF (p-XRF) has some limitations that are addressed in this study. The performance assessment of four different p-XRF units and the reconciling of their output were conducted. The results show the limitations in cross-referencing the data obtained from each unit and suggest procedures to overcome the issues. The p-XRF units were tested on the set of Corning reference glasses and on a small set of archaeological glasses with known composition. The compatibility of the output was assessed using multivariate statistical tools. Such a workflow allows us to consider data from multiple sources in the same frame of reference.

Several types of (mostly) blue-green glass beads from Iron-Age archaeological sites in Central Italy were studied using a range of spectroscopic techniques: portable X-Ray Fluorescence spectrometry, Fibre Optics Reflectance Spectroscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectrometry, micro-Raman spectroscopy and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Complementary information was gathered from each technique and discussed in the frame of the archaeological typology of the objects. The systematic evaluation of the results allowed us to draw some conclusions on the raw materials employed for primary production and to highlight some provenance indicators in the glass. Some of the beads found in the Iron Age (IA) contexts were preliminarily attributed to the Final Bronze Age (FBA) production based on their typology, and the compositional data obtained in this work confirmed that they were low magnesium high potassium (LMHK) glass, typical of FBA in the Italian peninsula. Other beads were assigned to low magnesium glass (LMG) or high magnesium glass (HMG), thus giving further information on the fluxing agents employed in the Early Iron Age (EIA) and beyond. Colour variations among the beads reflected their chemical composition, with different bead typologies coloured in a specific way. In some instances, it was possible to establish different origins for the colouring raw materials. The provenance of the samples was difficult to place, but the chemical evidence suggested a subdivision within the raw glass used to produce the beads: for one set of samples, a local origin of the glass could be hypothesised, whereas several production sites in the Near East were suggested for most of the beads considered in this study. Some preliminary clues for the local working of imported glass were also highlighted for one typological group.

Due to the absence of direct data on glass-making facilities in the Mediterranean Europe prior to the Hellenistic period, the Yahorlyk workshop (VI century BC) gains a particular importance. The workshop is situated along the coast of Yahorlyk bay, a shallow and long body of water in the Southern Ukraine, Kherson region. It was investigated on numerous occasions since 1972 and yielded abundant evidence of iron-production and bronze-working. The glass objects (remains of vitreous by-products, broken and complete beads etc.) are also common. Over 60 samples of glass were analyzed by A.S. Ostroverkhov and V.A. Galibin in 1980-ies. These results eneabled A.S. Ostroverkhov to put forward a hypothesis of local glass production at the Yahorlyk site. This paper tests this hypothesis on the basis of re-analysis of old dataset and a small series of samples treated by modern, enhanced methods of chemical analysis XRF, SEM-EDS and ICPMS in Hercules laboratory at Evora (Portugal). The old dataset, when revisited, revealed evidence of three types of glass that were worked by Yahorlyk craftsmen: low magnesia, high magnesia and a particular «third» type, which characteristic for glass pieces of undefined shape. These types are not only different by ratio of potassium and magnesium but also have a variable chemical composition in general. Namely, the percentage of alumina varies greatly: it are almost absent in low magnesia glass and relatively high in high magnesia glass. It is low in the objects of the «third» type as well, making this chemical type similar to low magnesia glass. The samples of sands were selected at different outcrops around the settlement and the content of rare earth elements (REE) was studied. Several samples were rejected as possible sources of sand for glass production. However, two samples (Qua and Iv-s) demonstrate significant similarities with REE composition in glass beads from Yahorlyk site. Low magnesia glass beads (biconical beads) form two distinct groups on the graph of REE. Thus, at least two different types of sands were employed in their production. None of the local sand samples resembles chemical composition of biconical beads. Low magnesia glass was imported from elsewhere and the beads were produced from that material on the site. High magnesia glass beads (mostly eye-beads) appear to correlate in the REE graphs of two sand samples Qua (sand from a quarry on the southern coast of Dnieper bay) and Iv-s (sand from the plane where one of the Dnieper presently non-existent branches entered Yahorlyk bay). The latter has too high content of alumina to be a source of sand for the beads analyzed recently. However, there were several beads with equally high alumina content in the old dataset. The former sediment sample (Qua) corresponds the REE composition of high magnesia beads from the Yahorlyk site and can be a source of raw material for their production. High magnesia glass could be produced at the Yahorlyk workhop and later worked into eye beads there. Thus, new analyses proved an old hypothesis of A.S. Ostroverkhov about local glass-making at the Yahorlyk workshop. This fact makes the site of Yahorlyk a crucial archaeological source for research on Archaic glass-working in the Pontic Region as well as in the ancient Greece and Mediterranean basin in general. У статті висвітлено результати вивчення скляних намистин з Ягорлицького поселення та зразків піску довкола нього. У дослідженні використовувались методи природничих наук, а саме XRF, SEM-EDS та ICPMS. Хімічний склад намистин із золистого скла та піску свідчить про їх спорідненість за макроелементами та рідкісноземельними елементами. Отримані результати підтверджують гіпотезу А.С. Островерхова про місцеве виробництво скла.

This work reports the results of the analyses performed on a set of glass finds from the “Gaetano Chierici” collection in the Civic Museums of Reggio Emilia. Forty-eight typologically heterogeneous glass finds were included in the list of the analyzed objects, dating from the fifth century BCE to the first century CE. The objects primarily consisted of glass beads; however, bangles, pinheads, and one vessel fragment were also included in the set. The items were analyzed using non-invasive spectroscopic methods that were implemented with portable equipment on the museum’s premises. Fiber optic reflectance spectroscopy was used to identify the coloring species in the glass matrix, while X-ray fluorescence spectrometry provided compositional information. Both techniques allowed for a discussion of the mechanisms of coloring and opacification, as well as the raw materials used for this purpose. The results provided a complex picture of the various colorants used to manipulate the appearance of the glass, which was a crucial aspect in the creation of the personal adornments represented by these glass items. The data revealed evidence of different sources of raw glass and colorants. Most of the samples were colored with cobalt, but iron and copper also influenced the color of many of them. Both white and yellow were utilized for the glass decorations, and these colors were achieved with the addition of either antimony-containing crystals or tin-containing ones. This finding suggests that the transition from antimonate to stannate started as early as the second century BCE. The “Gaetano Chierici” collection contains representative objects distributed throughout the investigated period. The results obtained here are a starting point for future studies of glass technology and provenance in the area.