Stained-glass window medieval

The belief that a glass is a supercooled liquid in which atomic motions have slowed to the extent that characteristic relaxation time exceeds the observation period (1000 years for stained medieval windows) is debated and the possibility that glass corresponds to a... 

Vassas, C. D., Chemical, Thermal-Analysis, and Physical Study of Glasses of Medieval Stained-Glass Windows, Int. Congr. Glass, Artistic Hist. Commun., 9th, 1971 (1972) 241-266 (French). 

THE glorious medieval stained-glass windows of European cathedrals have been the subject of several chemical analyses to support conservation projects, to identify workshops and their practices, and to attempt the association of colors with specific metal ions in various oxidation states. However, little information of this sort has been generated from the beautifully decorated, enameled, and gilded copper ecclesiastical objects used in medieval cathedrals that are recognized under the generic name of Limoges enamels. 

Figure 5 Medieval stained glass window from Erfurt (Germany) with a dense crust of weathering products, a cross section, SEMpicture (left) and element mapping (EDX) (right) (Note elements are specified in the picture (Ca, K, S, Si))...

Degradation processes in medieval stained glass windows have been studied using FT-IR spectroscopy and the pigments applied to early specimens have been characterized using the FT-Raman technique. Similar methods have been used to study early enamels and cloisonne specimens. 

The decreasing levels of SO2 and increasing frequency of car traffic has resulted in a new multi-pollutant situation in many urban and industrial areas. In order to possibly quantify the corrosion effects caused by this new multi-pollutant situation an extended exposure program was performed that took place between 1997 and 2001 and involved some 30 test sites in 18 countries in Europe and North America [91]. Specimens of carbon steel, zinc, copper, bronze, limestone, paint-coated steel, and glass representative of medieval stained glass windows were exposed for up to four years. At each site, the environmental data measured included climatic parameters (temperature, relative humidity, and sunshine radiation), gaseous pollutants (SO2, NO2, HNO3, and O3), particles (presented as PMio, i.e., concentration of particles with diameter < 10 pm), and precipitation (total amount, conductivity, and concentration of, i.e., H+, S04 , N03, Cl", NH4+). 

Glass Making Glass and the art of glassmaking have been known for millennia. Beautiful stained-glass windows can be seen in medieval and modern churches ancient glass containers for perfume and oil are displayed in many museums. Today, glass is indispensable in almost every facet of life. 

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