The Provenance of Glass

The four isotopes, as those of any element, have the same chemical properties. The four are not, however, uniformly distributed in the earth s crust the occurrence of three of them, in minerals and rocks, is associated with the radioactive decay of isotopes of thorium and uranium. In most minerals and rocks the relative amounts (or the isotopic ratios) of the isotopes of lead (often expressed relative to the amount of stable lead-204) are generally within well-known ranges, which are independent of the composition of the mineral or rock they are, however, directly related to the amounts of radioactive thorium and uranium isotope impurities in them. 

Minerals and rocks of similar composition but of different geographic or geologic origin generally include different relative amounts of thorium and uranium impurities after generally long periods of time they also include, therefore, different relative amounts of the isotopes of lead. The 

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FIGURE 22 Obsidian in the eastern Mediterranean Sea area. Studying the relative concentration of trace elements in obsidian makes it possible to identify the obsidian and to determine its provenance. Determining the relative amounts of barium and zirconium in ancient obsidian tools and in samples from different sources of the natural glass, for example, made it possible to identify the provenance of obsidian used in eastern Mediterranean Sea area sites (Renfrew and Dixon 1976). 

Freestone, I. C. (2005), The provenance of ancient glass through compositional analysis, in Vandiver, P. B., J. L. Mass, and A. Murray (eds.), Materials Issues in Art and Archaeology VII (Symposium, November 30-December 3, 2004, Boston, Massachusetts), Materials Research Society Symposium Proceedings, Vol. 852, Materials Research Society, Warrendale, Pennsylvania. 

The final group consists of 32 pieces of medieval glass from various sources which were part of the collection of The Cloisters Museum and were donated to the Corning Museum of Glass. Since the provenances of these specimens are not well established, the data for them cannot be used to characterize particular structures or glass workshops. These samples show the extensive variation in composition which does exist in medieval stained glass from different sources. Some, however, can be grouped upon the basis of similar composition. 

Several approaches to the description of molecular entanglements in polymers are available at present. A brief outline will be given here. The best known is the version of the binary hook [9,10] with some network features. At temperatures (T) exceeding the temperature of glass transition (Tg) for the polymer, the network density V(,i, is usually determined in the framework of the rubber-like elasticity, while for Tentanglement network is proven both theoretically and... 

This ancient recycling system makes it difficult for archeologists to determine the provenance of a glass object from its chemical composition alone. A structured recycling program for domestic glass waste started in 1975 and was initiated by the glassmaking compaifies. 

Jackson, C.M., Nicholson, P.T. (2010) The provenance of some glass ingots from the Uluburun shipwreck. Journal of Archaeological Science, 37,295-301. 

Henderson, J. (2009) The provenance of archaeological plant ash glasses, in From Mine to Microscope Advances in the Study of Ancient Technology (eds. 

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