Medieval glass

Figure 8 Archaeological glass, medieval, with enamel-like surface layer, an overview...

The windows in some medieval cathedrals show greater thickness at the bottom than at the top, owing to the slow flow of the glass under the influence of gravity. 

Natron and ash of seaweeds provided the sodium which served as the flux in all glasses till the Medieval period. Wood ashes then came into use, which changed the glass formulation to such a degree that potassium salts became the principal fluxing alkaUes. 

Venice became the world s glassmaking center in medieval times. Small, flat panes were produced by cutting and rolling flat hot, blown glass. This technique was used for the buildings constrncted by early European settlers in America. 

Clusters of metal atoms can form colloidal suspensions. Colloidal clusters of copper, silver, and gold in glass are responsible for some of the vivid colors of stained glass in medieval cathedrals. Even aqueous suspensions of metal clusters are known (Fig. 8.45). 

The adhesive was developed for application to seal food containers with alumina foils and to seal glass plates. In this case, the vinyl polymerization step can be carried out by UV light radiation through the already mounted glass plates with a photoactive radical initiator to cure the viscous adhesive material. Another application of this material is the development of diffusion barrier containing protective coatings on medieval stained glasses (31). 

Pollard, A. M. (1979), X-Rays Fluorescence and Surface Studies of Glass with Application to the Durability of Medieval Window Glass, Ph.D. thesis, Univ. York. 

Schreiner, M., I. Prohaska, J. Rendl, and C. Weigel (1998), Leaching studies of potash-lime-silica glass with medieval glass composition using AAS and IRRS, in Tennent, N. (ed.), Conservation of Glass and Ceramics, James and James, London. 

Schreiner, M., G. Woisetschlager, I. Schmitz, and M. Wadsak (1999), Characterization of surface layers formed under natural conditions on medieval stained glass and ancient copper alloys using SEM, SIMS and AFM, ]. Anal. Atomic Spectrom. 14(3), 395 03. 

In an analytical study of the relationship between the chemical composition and corrosion behaviour of Medieval window glass from York Minster (Pollard, 1979), a total of more than 200 samples were analysed, dating mainly from the 12th, 14th and 15th Centuries. A summary of the findings has been... 

Figure 5.11 Plot of 87Sr/86Sr vs eNd for some examples of English Medieval cathedral window glass. (Wilson, Pollard and Evans unpublished data key in Table 5.4)...

Cox, G.A. and Gillies, K.J.S. (1986). The X-ray fluorescence analysis of Medieval blue soda glass from York Minster. Archaeometry 28 57-68. 

Gillies, K.J.S and Cox, A. (1988a). Decay of medieval stained glass at York, Canterbury and Carlisle. Part 1. Composition of the glass and its weathering crusts. Glastechnische Berichte 61 75-84. 

Iliffe, C.J. and Newton, R.G. (1976). Using triangular diagrams to understand the behaviour of Medieval glass. Verres et Refractaires 30 30-34. 

Jantzen, C.M. and Plodinec, M.J. (1984). Thermodynamic model of natural, Medieval and nuclear waste glass durability. Journal of Non-Crystalline Solids 67 207-223. 

Newton, R.G. (1978). Colouring agents used by Medieval glassmakers. Glass Technology 19 59-60. 

Schreiner, M. (1988). Deterioration of stained medieval glass by atmospheric attack. Part 1. Scanning microscopic investigations of the weathering phenomena. Glastechnische Berichte 61 197-204. 

Figure 9.9 REE abundances from archaeological glass, showing the effect of chondrite normalization, (a) shows the raw abundances of the REE measured on a set of English medieval window glasses, with the saw-tooth pattern evident, and little indication of differences between any of the samples (apart from perhaps one which has lower overall REE concentrations), (b) shows the same data normalized to the chondrite data (Table 9.1). The saw-tooth has largely disappeared, and close inspection suggests that two samples have a positive europium anomaly, possibly indicating a different geographical origin.

Bertoncello, R., Milanese, L., Russo, U., et al. (2002). Chemistry of cultural glasses the early medieval glasses of Monselice s hill (Padova, Italy). Journal of Non-Crystalline Solids 306 249-262. 

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