Composition, Production and Procurement of Glass at San Vincenzo al Volturno: An Early Medieval Monastic Complex in Southern Italy

Abstract

136 glasses from the ninth-century monastery of San Vincenzo and its workshops have been analysed by electron microprobe in order to situate the assemblage within the first millennium CE glass making tradition. The majority of the glass compositions can be paralleled by Roman glass from the first to third centuries, with very few samples consistent with later compositional groups. Colours for trailed decoration on vessels, for vessel bodies and for sheet glass for windows were largely produced by melting the glass tesserae from old Roman mosaics. Some weakly-coloured transparent glass was obtained by re-melting Roman window glass, while some was produced by melting and mixing of tesserae, excluding the strongly coloured cobalt blues. Our data suggest that to feed the needs of the glass workshop, the bulk of the glass was removed as tesserae and windows from a large Roman building. This is consistent with a historical account according to which the granite columns of the monastic church were spolia from a Roman temple in the region. The purported shortage of natron from Egypt does not appear to explain the dependency of San Vincenzo on old Roman glass. Rather, the absence of contemporary primary glass may reflect the downturn in long-distance trade in the later first millennium C.E., and the role of patronage in the “ritual economy” founded upon donations and gift-giving of the time.

Les vitraux alto-médiévaux de Stavelot (Belgique)

“…La fabrication des vitraux de cette couleur pourrait également reposer sur le recyclage d'objets antérieurs car, à cette i n, h éophile mentionne la récupération de vaisselle et de tesselles bleues romaines mélangées à du verre incolore (h eophili, 1876). L'existence de ces recettes est prouvée à San Vincenzo (Schibille et Freestone, 2013 (Gratuze, 2013). Cette origine peut donc être écartée.…”

Tesserae Recycling in the Production of Medieval Blue Window Glass

“…Along with this written source, some archaeological finds support this hypothesis. For instance, half‐molten tesserae were found in glass ingots at San Vincenzo al Volturno (Dell’Acqua ; Schibille and Freestone ) and in Germany at Lorsch and Paderborn (Sanke et al . ), thus proving that, at least at some sites, tesserae were remelted for the production of glass.…”

“…For this reason, an increasing number of publications have grappled with the issue of glass recycling in ancient times (e.g., Foster and Jackson 2010;Freestone 2015;Jackson and Paynter 2015). It is generally accepted that archaeometric studies allow glass recycling to be recognized by the detection of colourant elements (e.g., Cu and Pb) in weakly coloured and transparent glass or, conversely, decolourants (Mn and Sb) in coloured glass (Freestone and Hughes 2006;Silvestri 2008;Silvestri et al 2008;Schibille and Freestone 2013). Silvestri (2008) established the first recycling index for quantifying the extent of recycling of Roman colourless (or naturally coloured) glass.…”

Pattern in Glass Use in the Roman and Byzantine Worlds: A Report on Current Research at the Institute of Archaeology and UCL Qatar

“…Unsurprisingly, settlements on the west coast of the Sinai have a mixture of glass from both provinces (Kato et al 2008). A much more varied supply picture, however, is seen further afield, both in the Mediterranean and the Roman provinces (Freestone et al 2002b(Freestone et al , 2008Cholakova 2010, 2014;Schibille and Freestone 2013). Very unexpected, and of major importance for our understanding of the Late Roman glass industry, was the recent study of an assemblage from Pergamon undertaken by members of the Research Network.…”