The four Spanish limestone tombs of Urgell at the Cloisters in New York were once believed to hav... more The four Spanish limestone tombs of Urgell at the Cloisters in New York were once believed to have been commissioned in 1314 by Ermengol X, Count of Urgell, for a memorial chapel at the monastery of Las Avellanas in northern Spain. Historical evidence suggests instead that the tombs were not at the monastery until the seventeenth and eighteenth centuries, and may be assemblages of fourteenth-century and later tomb sculpture brought to the monastery from other sites. Results of a materials study support a fourteenth-century origin and a common local source for all elements of the tombs, and provide evidence that the four tombs in their current configurations were in place together at the end of the seventeenth century. However, they also strongly suggest a much earlier, though not necessarily original, relationship among some of the various elements, particularly in the large composed tomb identified as that of Ermengol VII.
This study presents the analyses of a group of glass mosaic tesserae from the middle Byzantine pe... more This study presents the analyses of a group of glass mosaic tesserae from the middle Byzantine period excavated at Amorium in central Anatolia. Quantitative analysis of the tesserae was performed using X-ray microanalysis in the scanning electron microscope (SEM-EDS/WDS) to characterize the overall compositions of the glasses as well as the colorants and opacifiers. All of the tesserae were found to have soda-lime-silica compositions with relatively low levels of magnesia and potash, consistent with so-called natron glass. Green opaque tesserae were found to be opacified in part by crystalline lead stannate, while opaque turquoise tesserae were found to contain inclusions consisting mainly of calcium phosphate, probably in the form of bits of bone or ivory, as well as many bubbles or voids which also help to opacify the glass.
This study presents the analyses of enamel compositions from a group of European enamelled gold j... more This study presents the analyses of enamel compositions from a group of European enamelled gold jewelry dating from the sixteenth and seventeenth century, as well as from a group pf enamelled gold objects from the late nineteenth century. Quantitative analyses of the enamel compositions were done using X-ray microanalysis in the scanning electron microscope (SEM-EDS/WDS) to characterize the overall compositions as well as identify the opacifiers, colourants and associated elements.
Among the most notable contributions of Islamic craftsmen to the art of glassmaking are thirteent... more Among the most notable contributions of Islamic craftsmen to the art of glassmaking are thirteenth-and fourteenth-century gilded and enameled glasses from Egypt and Syria. In order to better understand their manufacture, quantitative chemical analyses were performed on samples of glass substrates and enamels from a group of medieval Egyptian and Syrian vessels and mosque lamps in The Metropolitan Museum of Art, using energy dispersive and wavelength dispersive X-ray spectrometry in the scanning electron microscope. For comparison, analyses were also carried out on two nineteenth-century European vessels in the Islamic style. Whereas earlier technical investigations of the medieval material had helped to define the various glass and enamel formulations employed, the present study provides a more comprehensive overview of the glass and enamel types and pigments in use, as well as identifying pigment mixtures in individual enamels. Different combinations of enamel types consistently used together on individual vessels were recognized; on further investigation, these may prove to be indicative of dating or a particular production site.
The four Spanish limestone tombs of Urgell at the Cloisters in New York were once believed to hav... more The four Spanish limestone tombs of Urgell at the Cloisters in New York were once believed to have been commissioned in 1314 by Ermengol X, Count of Urgell, for a memorial chapel at the monastery of Las Avellanas in northern Spain. Historical evidence suggests instead that the tombs were not at the monastery until the seventeenth and eighteenth centuries, and may be assemblages of fourteenth-century and later tomb sculpture brought to the monastery from other sites. Results of a materials study support a fourteenth-century origin and a common local source for all elements of the tombs, and provide evidence that the four tombs in their current configurations were in place together at the end of the seventeenth century. However, they also strongly suggest a much earlier, though not necessarily original, relationship among some of the various elements, particularly in the large composed tomb identified as that of Ermengol VII.
This study presents the analyses of a group of glass mosaic tesserae from the middle Byzantine pe... more This study presents the analyses of a group of glass mosaic tesserae from the middle Byzantine period excavated at Amorium in central Anatolia. Quantitative analysis of the tesserae was performed using X-ray microanalysis in the scanning electron microscope (SEM-EDS/WDS) to characterize the overall compositions of the glasses as well as the colorants and opacifiers. All of the tesserae were found to have soda-lime-silica compositions with relatively low levels of magnesia and potash, consistent with so-called natron glass. Green opaque tesserae were found to be opacified in part by crystalline lead stannate, while opaque turquoise tesserae were found to contain inclusions consisting mainly of calcium phosphate, probably in the form of bits of bone or ivory, as well as many bubbles or voids which also help to opacify the glass.
This study presents the analyses of enamel compositions from a group of European enamelled gold j... more This study presents the analyses of enamel compositions from a group of European enamelled gold jewelry dating from the sixteenth and seventeenth century, as well as from a group pf enamelled gold objects from the late nineteenth century. Quantitative analyses of the enamel compositions were done using X-ray microanalysis in the scanning electron microscope (SEM-EDS/WDS) to characterize the overall compositions as well as identify the opacifiers, colourants and associated elements.
Among the most notable contributions of Islamic craftsmen to the art of glassmaking are thirteent... more Among the most notable contributions of Islamic craftsmen to the art of glassmaking are thirteenth-and fourteenth-century gilded and enameled glasses from Egypt and Syria. In order to better understand their manufacture, quantitative chemical analyses were performed on samples of glass substrates and enamels from a group of medieval Egyptian and Syrian vessels and mosque lamps in The Metropolitan Museum of Art, using energy dispersive and wavelength dispersive X-ray spectrometry in the scanning electron microscope. For comparison, analyses were also carried out on two nineteenth-century European vessels in the Islamic style. Whereas earlier technical investigations of the medieval material had helped to define the various glass and enamel formulations employed, the present study provides a more comprehensive overview of the glass and enamel types and pigments in use, as well as identifying pigment mixtures in individual enamels. Different combinations of enamel types consistently used together on individual vessels were recognized; on further investigation, these may prove to be indicative of dating or a particular production site.
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Papers by Mark Wypyski
the tombs were not at the monastery until the seventeenth and eighteenth centuries, and may be assemblages of fourteenth-century and later tomb sculpture brought to the monastery from other sites. Results of a materials study support a fourteenth-century origin and a common local source
for all elements of the tombs, and provide evidence that the four tombs in their current configurations were in place together at the end of the seventeenth century. However, they also strongly suggest a much earlier, though not necessarily original, relationship among some of the various elements, particularly in the large composed tomb identified as that of Ermengol VII.
the tombs were not at the monastery until the seventeenth and eighteenth centuries, and may be assemblages of fourteenth-century and later tomb sculpture brought to the monastery from other sites. Results of a materials study support a fourteenth-century origin and a common local source
for all elements of the tombs, and provide evidence that the four tombs in their current configurations were in place together at the end of the seventeenth century. However, they also strongly suggest a much earlier, though not necessarily original, relationship among some of the various elements, particularly in the large composed tomb identified as that of Ermengol VII.