Print Email Facebook Twitter Degradation processes in colourless Roman glass: Cases from the Bocholtz burial Title Degradation processes in colourless Roman glass: Cases from the Bocholtz burial Author Huisman, D.J. Pols, S. Joosten, I. van Os, B.J.H. Smit, A. TNO Bouw en Ondergrond Publication year 2008 Abstract A group of Roman glass objects from the Bocholtz burial in the SW of Limburg (The Netherlands) was found to have been subject to varying degrees of degradation. Many of the 25 colourless glass objects were fragmented to pieces <0.1 cm ("sugared"), whereas the three transparent blue-green glass objects were in near-pristine state. Analyses using SEM, XRF and EDS revealed that the fragmentation was the direct result of the intense leaching of Na2O from the glass structure and its replacement with water. The resulting gel layers with low-Na2O contents and large amounts of water are sensitive to cracking when they dry out. Thin-walled glass appears to be less sensitive to cracking from the resulting stress than thick-walled glass. Local differences in the moisture regime during burial also influence the severity of the glass degradation. Glass with low concentrations of CaO seems to be the most sensitive to this form of degradation. The typical blue-green Roman glass is less sensitive as it generally has considerably higher concentrations of CaO. "Sugared" glass has - until now - only been reported in a small number of high-status burials. However, glass fragments that are degraded as strongly as some of the objects in the Bocholtz burial may have been overlooked in other archaeological settings (e.g. settlements), especially in coarse-grained soils or soils containing debris or rock fragments. As a result, the archaeological record for Roman glass may be biased towards the "typical" blue-green transparent glass objects. © 2007 Elsevier Ltd. All rights reserved. Subject Geosciences"Sugaring"DegradationGel layerGlassGlass colourLeachingSoil moisturearchaeologyconcentration (composition)degradationglassleachingscanning electron microscopyX-ray fluorescenceBelgiumBeneluxBocholtEurasiaEuropeLimburg [Belgium]Western Europe To reference this document use: http://resolver.tudelft.nl/uuid:5c5e8361-e038-4c70-8c4d-9ae4d94602bf TNO identifier 240653 ISSN 0305-4403 Source Journal of Archaeological Science, 35 (2), 398-411 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.