Gilded and enamelled glasses of Islamic style, coming from a 13th century landfill in Melfi castle, a Swabian emperor Frederick II fortress, were subjected to a multi-techniques approach in order to explore the complex and very fascinating ancient production technology of gilding and enamelling on glass. Non-destructive μ-Raman spectroscopy was employed on the most important and well-preserved objects, optical (OM) and electron (SEM) microscopies were used to investigate the sections stratigraphy of tiny fragments sampled from the borders of the already damaged objects. In order to provide the chemical analyses of the bodies and the enamels, energy dispersive X-rays spectroscopy (EDS) and X-rays photoelectron spectroscopy (XPS) were also employed. The body of the objects proved to be made of silica-soda-lime glass, while the enamels of lead-rich glass (“soft enamels”) and coloured by lapis lazuli and cobalt for blue, hematite and minium for red, lead-tin yellow for green and calcium phosphate for white. The gilding was found to be applied on a red enamel basis. The presence of carbon inside the gildings and the detection of two different gold signals by XPS suggested the hypothesis of the use of the so-called “liquid gold”. This study gave thus an important contribution to the understanding of the production of this class of rare and precious objects, also confirming that the materials and technological procedures are consistent with the Islamic tradition, probably due to the presence of Islamic artisans at the court of Frederick II.
Multi-spectroscopic approach to explore the technological features of medieval gilded and enamelled glasses from Melfi (PZ)
GIANNOSSA, LORENA CARLA;DITARANTO, NICOLETTA;LAVIANO, Rocco;SABBATINI, Luigia;MANGONE, Annarosa
2012-01-01
Abstract
Gilded and enamelled glasses of Islamic style, coming from a 13th century landfill in Melfi castle, a Swabian emperor Frederick II fortress, were subjected to a multi-techniques approach in order to explore the complex and very fascinating ancient production technology of gilding and enamelling on glass. Non-destructive μ-Raman spectroscopy was employed on the most important and well-preserved objects, optical (OM) and electron (SEM) microscopies were used to investigate the sections stratigraphy of tiny fragments sampled from the borders of the already damaged objects. In order to provide the chemical analyses of the bodies and the enamels, energy dispersive X-rays spectroscopy (EDS) and X-rays photoelectron spectroscopy (XPS) were also employed. The body of the objects proved to be made of silica-soda-lime glass, while the enamels of lead-rich glass (“soft enamels”) and coloured by lapis lazuli and cobalt for blue, hematite and minium for red, lead-tin yellow for green and calcium phosphate for white. The gilding was found to be applied on a red enamel basis. The presence of carbon inside the gildings and the detection of two different gold signals by XPS suggested the hypothesis of the use of the so-called “liquid gold”. This study gave thus an important contribution to the understanding of the production of this class of rare and precious objects, also confirming that the materials and technological procedures are consistent with the Islamic tradition, probably due to the presence of Islamic artisans at the court of Frederick II.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
