Archaeological and archaeometric study of the glass finds from the ancient harbour of Classe (Ravenna- Italy): new evidence

Abstract

Introduction: The present study focuses on Late-Roman/Early Medieval glass found in the productive area within the ancient harbour of Classe near Ravenna, one of the most important trade centres between the 5 th and 8 th centuries AD of the Northern Adriatic area. Aims of the study were the identification of the main glass compositions and their contextualisation in Late-Antique groups; the identification of provenance of raw glass, and, consequently, of commercial routes; the extent, if any, of recycling glass cullet, as an alternative to the import of fresh raw glass; the identification of possible connections between archaeological typology and glass chemical composition.Results: 32 glassworking wastes and 25 drinking vessel fragments for a total amount of 57 fragments were devoted to chemical analysis in XRF and EPMA. All the analysed fragments are silica-soda lime glasses, produced with natron as a flux, and are compositionally similar to Late-Antique groups HIMT, Série 3.2 and Levantine1. Raw glass chunks, glassworking wastes and objects of comparable compositions are identified into HIMT and Série 3.2 groups, while the Levantine 1 group includes only objects and glassworking wastes. Systematic comparisons between Classe and Aquileia, the two most important Late-Antique archaeological sites of North-Eastern Italy, were also carried out, and the same compositional groups were identified, although Série 3.2 in the Classe assemblage is more represented. Sr and Nd isotopic analysis confirmed that the composition of the three glasses derive from coastal sands of the Syro-Palestinian and Egyptian shore, with a slight shift in comparison to the published data. Little evidence of recycling was identified in the assemblage. Conclusions:In the 5 th century, a secondary glass workshop devoted to the shaping of glass vessels starting from raw glass chunks and, possibly, glass cullet, was active in the area of the harbour. Raw glass of HIMT and Série 3.2 was imported from the Levant and Egypt. Comparisons between Classe and Aquileia show that during the Late Antiquity these sites seem to be supplied of raw glass by the same trade routes. In addition, some connections between types and chemical compositions were highlighted.

The Supply of Glass at Portus Ilicitanus (Alicante, Spain): A Meta‐Analysis of HIMT Glasses

“…Seventeen out of 47 HIMT samples analysed from Aquileia and the late Roman harbour of Classe correspond to HIMTb (Maltoni et al . , ). In the rest of Italy, in contrast, as well as at Carthage, HIMTa tends to be the dominant type (Schibille et al .…”

“…Given the overlap of the two groups at low iron concentrations, a second criterion was applied, whereby all samples with Fe 2 O 3 < 2% were attributed to HIMTa. Data were taken from Rius et al (), Mirti et al (), Freestone et al (, ), Foy et al (), Uhlir (), Arletti et al (, ), Wolf et al (), Blin and Vanpeene (), Gómez‐Tubío et al (), Carmona et al (), Da Cruz (), Foster and Jackson (), Rehren et al (), Castelo et al (–12), Schibille (), Palomar et al (), Schiavon et al (), Schibille et al (, ), Conte et al (), Möncke et al (), Rosenow and Rehren (), Agua et al (), Di Bella et al (), Gliozzo et al (), Gliozzo et al (,b, ,b), Maltoni et al (, ), Rehren and Brüggler (), Jackson and Paynter (), Smith et al (), Ceglia et al (), De Juan Ares and Schibille (,b) and Siu et al (). [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…), as well as at Ravenna and Aquileia (Maltoni et al . , ). In contrast, HIMT seems less widespread in Syria–Palestine and Asia Minor (Fig.…”

The elusive early medieval glass

“…This could simply be the result of the fact the coarse pottery dating is very imprecise for northern Italy and slovenia (and Croatia) in the early medieval period. yet assemblages to up to the 8 th century can be discerned at least in Italy and it is the 9 th -10 th century that represents a particular problem when glass vessels are concerned (sternini 1995: 262;Mirti et al 2001;stiaffini 2006: 669-670;Ferri 2006;Maltoni et al 2015). Another possible explanation for this absence could be the scarcity of fresh raw glass and the rising level of recycling in the 9 th and 10 th century (saguì, Lepri 2015: 229).…”

“…To je lahko preprosto posledica dejstva da je datiranje grobe keramike za severno Italijo in slovenijo (in hrvaško) v zgodnjem srednjem veku zelo neprecizno. Vendar sestavi najdb s steklom do 8. st. vsaj v Italiji obstajajo in šele 9. in 10. st. predstavljata poseben problem (sternini 1995: 262;Mirti et al 2001;stiaffini 2006: 669-670;Ferri 2006;Maltoni et al 2015). Druga možna razlaga je lahko pomanjkanje svežega surovega stekla in posledično naraščajoče recikliranje stekla v 9. in 10. st. (saguì, Lepri 2015: 229).…”