Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork

A complete study of the decayed gilded decorations of the stalactite vaults in the Hall of the Kings in the Alhambra complex (Granada, Spain) has been carried out for the first time. Preliminary investigations were carried out in situ using a portable Raman spectrometer and enabled the identificatio...

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Autores: de-la-Torre-López, María José, Domínguez-Vidal, Ana, Campos-Suñol, María José, Rubio-Domen, Ramón, Schade, Ulrich, Ayora-Cañada, María José
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2014
País:España
Recursos:Universidad de Jaén
Repositorio:RUJA. Repositorio Institucional de la Producción Científica de la Universidad de Jaén
OAI Identifier:oai:ruja.ujaen.es:10953/4471
Acesso em linha:https://hdl.handle.net/10953/4471
Access Level:acceso abierto
Palavra-chave:Gilding
Alhambra
Plasterwork
Tin
Calcium oxalate
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spelling Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterworkde-la-Torre-López, María JoséDomínguez-Vidal, AnaCampos-Suñol, María JoséRubio-Domen, RamónSchade, UlrichAyora-Cañada, María JoséGildingAlhambraPlasterworkTinCalcium oxalateA complete study of the decayed gilded decorations of the stalactite vaults in the Hall of the Kings in the Alhambra complex (Granada, Spain) has been carried out for the first time. Preliminary investigations were carried out in situ using a portable Raman spectrometer and enabled the identification of tin (II) oxide in the black areas nearby the golden flakes. This suggested the presence of an altered tin foil. Then, a comprehensive characterization of these decorations was achieved through the use of complementary nondestructive techniques working on microsamples. Two main metallic structures were identified by means of scanning electron microscopy coupled to energy dispersive X-ray spectroscopy: (1) a thin (1–2 μm) gold leaf (probably original), and (2) redecorations with a laminated structure formed by a gold leaf placed over a thicker (10–15 μm) tin foil. Synchrotron Fourier transform infrared microspectroscopy revealed the use of proteinaceous glue to fix the gold leaf directly on the plasterwork, whereas in the case of the laminated structures, either glue or a natural resin was found. Raman microspectroscopy provided insight into the main decay processes affecting the gildings: the detachment of the metals due to the alteration of the organic materials employed as adhesives (forming calcium oxalates) and the oxidation of the tin foil. In addition, two technologies of false gilding have been encountered. One was based on a tin foil tinted to look like gold by means of a varnish (composed of a drying oil and a natural resin), and the second was made up with a tin–copper alloy (bronze) that appears severely degraded to copper oxalate and tin (II) oxide, as revealed by Raman microspectroscopy. Copyright © 2014 John Wiley & Sons, Ltd.Wiley202520252014info:eu-repo/semantics/articleinfo:eu-repo/semantics/acceptedVersionapplication/pdfhttps://hdl.handle.net/10953/4471reponame:RUJA. Repositorio Institucional de la Producción Científica de la Universidad de Jaéninstname:Universidad de JaénInglésJ. Raman Spectrosc., 45, pages 1052–1058info:eu-repo/semantics/openAccessoai:ruja.ujaen.es:10953/44712026-06-24T12:41:07Z
dc.title.none.fl_str_mv Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
title Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
spellingShingle Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
de-la-Torre-López, María José
Gilding
Alhambra
Plasterwork
Tin
Calcium oxalate
title_short Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
title_full Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
title_fullStr Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
title_full_unstemmed Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
title_sort Gold in the Alhambra: study of materials, technologies, and decay processes on decorative gilded plasterwork
dc.creator.none.fl_str_mv de-la-Torre-López, María José
Domínguez-Vidal, Ana
Campos-Suñol, María José
Rubio-Domen, Ramón
Schade, Ulrich
Ayora-Cañada, María José
author de-la-Torre-López, María José
author_facet de-la-Torre-López, María José
Domínguez-Vidal, Ana
Campos-Suñol, María José
Rubio-Domen, Ramón
Schade, Ulrich
Ayora-Cañada, María José
author_role author
author2 Domínguez-Vidal, Ana
Campos-Suñol, María José
Rubio-Domen, Ramón
Schade, Ulrich
Ayora-Cañada, María José
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Gilding
Alhambra
Plasterwork
Tin
Calcium oxalate
topic Gilding
Alhambra
Plasterwork
Tin
Calcium oxalate
description A complete study of the decayed gilded decorations of the stalactite vaults in the Hall of the Kings in the Alhambra complex (Granada, Spain) has been carried out for the first time. Preliminary investigations were carried out in situ using a portable Raman spectrometer and enabled the identification of tin (II) oxide in the black areas nearby the golden flakes. This suggested the presence of an altered tin foil. Then, a comprehensive characterization of these decorations was achieved through the use of complementary nondestructive techniques working on microsamples. Two main metallic structures were identified by means of scanning electron microscopy coupled to energy dispersive X-ray spectroscopy: (1) a thin (1–2 μm) gold leaf (probably original), and (2) redecorations with a laminated structure formed by a gold leaf placed over a thicker (10–15 μm) tin foil. Synchrotron Fourier transform infrared microspectroscopy revealed the use of proteinaceous glue to fix the gold leaf directly on the plasterwork, whereas in the case of the laminated structures, either glue or a natural resin was found. Raman microspectroscopy provided insight into the main decay processes affecting the gildings: the detachment of the metals due to the alteration of the organic materials employed as adhesives (forming calcium oxalates) and the oxidation of the tin foil. In addition, two technologies of false gilding have been encountered. One was based on a tin foil tinted to look like gold by means of a varnish (composed of a drying oil and a natural resin), and the second was made up with a tin–copper alloy (bronze) that appears severely degraded to copper oxalate and tin (II) oxide, as revealed by Raman microspectroscopy. Copyright © 2014 John Wiley & Sons, Ltd.
publishDate 2014
dc.date.none.fl_str_mv 2014
2025
2025
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
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dc.identifier.none.fl_str_mv https://hdl.handle.net/10953/4471
url https://hdl.handle.net/10953/4471
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv J. Raman Spectrosc., 45, pages 1052–1058
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Wiley
publisher.none.fl_str_mv Wiley
dc.source.none.fl_str_mv reponame:RUJA. Repositorio Institucional de la Producción Científica de la Universidad de Jaén
instname:Universidad de Jaén
instname_str Universidad de Jaén
reponame_str RUJA. Repositorio Institucional de la Producción Científica de la Universidad de Jaén
collection RUJA. Repositorio Institucional de la Producción Científica de la Universidad de Jaén
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