In 1982, a sixteenth-century botanical manuscript (MS 95) was discovered in the private archives ... more In 1982, a sixteenth-century botanical manuscript (MS 95) was discovered in the private archives of the De Paoli family, in the Upper Vara Valley in the Ligurian province of La Spezia. Based on non-invasive diagnostic techniques, analysis of the watermark and iconographical comparisons, we know that the manuscript MS 95 was produced in the area between Liguria and Tuscany. This essay highlights the importance of diagnostic analysis in cases where no information exists concerning the author and the provenance of a document. The identification of the materials used in the production of this manuscript and that of the iconographical representations reveal that the anonymous author was part of a vernacular culture that consulted printed books and library manuscripts and that local pigments and materials were probably used.
ABSTRACT Around 100 porcelain objects of the 18th century Rossetti, Vische and Vinovo manufacture... more ABSTRACT Around 100 porcelain objects of the 18th century Rossetti, Vische and Vinovo manufactures (Piedmont, Italy) from the Palazzo Madama Museum collection were analysed by means of an X-ray fluorescence portable detector. The present study represents the first chemical characterization of these early (1737–1825) European porcelains. Chemical composition data were submitted to multivariate clustering techniques that underscored a complete classification of the three manufactures and the presence of three subgroups for the Vinovo production. These resulting subgroups did not mirror the classification expected on the basis of the historiographic literature. The overall data pointed to technological continuity not only through all the Vinovo phases but even continuing from the earlier Vische manufacture.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015
Folium and orchil are dyes of vegetal origin. Folium is obtained from Chrozophora tinctoria (L.) ... more Folium and orchil are dyes of vegetal origin. Folium is obtained from Chrozophora tinctoria (L.) A. Juss., whereas orchil is obtained from Roccella and other genera of lichens. These dyes were used in the past to impart purple hue to paintings and textiles as substitutes for the more prised Tyrian purple dye, obtained from shellfish. Despite several citations in ancient technical treatises dating back at least to the Greek-Roman age, the identification of these dyes in artworks is rare. In the case of folium, an additional drawback is that its composition is presently unknown. In this work different non-invasive (FT-IR, FT-Raman, fibre optic reflectance spectrophotometry, spectrofluorimetry, X-ray fluorescence spectrometry) and micro-invasive (surface enhanced Raman spectroscopy, matrix assisted laser desorption ionisation-time of flight-mass spectrometry, inductively coupled plasma-mass spectrometry) techniques were used in order to increase the diagnostic information available on these dyes. Measurements were carried out on the dyes extracted from raw materials and on painted or dyed parchments. The possibility to distinguish between folium and orchil by chemical analysis is discussed.
This paper will present portable X-ray fluorescence (pXRF) analysis applied in situ to three 11th... more This paper will present portable X-ray fluorescence (pXRF) analysis applied in situ to three 11th-12th century manuscripts covers considered as masterpieces of Northern Italy medieval jewellery: Pace di Ariberto (Milano), Liber Evangeliorium of Vercelli and Pace di Chiavenna. These objects show a sumptuous decoration of golden leaves, plates and filigrees, enamels and casted gems. The aim of this research is to obtain information on manufacturing techniques and composition of the ace and artistic connections. XRF analysis was performed in order to determine the composition of the metals and enamels, and quantitative results, obtained using certified standards, undergo data treatment with multivariate analysis. The present paper will present a part of the results obtained on both the metals and glass materials, underlying the potential of pXRF in producing reliable results also when working in non-ideal conditions.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
Two Byzantine VI century manuscripts known as Vienna Dioskurides and Vienna Genesis, held in the ... more Two Byzantine VI century manuscripts known as Vienna Dioskurides and Vienna Genesis, held in the Austrian National Library at Vienna, were analysed with in situ non-invasive techniques. Raman spectroscopy, UV–Vis diffuse reflectance spectrophotometry with optic fibres and X-ray fluorescence spectrometry were used to characterise the palette of these early Middle Ages manuscripts. The analytical study was performed to have a better knowledge on the colourants used by ancient miniature painters, a subject known more on the basis of traditional sources (i.e. medieval treatises) than of analytical evidences. Indeed these illuminated manuscripts are, to the authors’ knowledge, among the oldest ever being analysed, so that the colourants found in them can be considered among the oldest evidences of their use. The main feature of Vienna Dioskurides and Vienna Genesis palettes is their richness, exemplified by the simultaneous presence of gold and ultramarine blue; in Vienna Dioskurides cinnabar is also present. Information regarding ultramarine blue is surprising, being the analytical evidence of the use of this precious pigment at least three centuries before its use in Western manuscripts, a feature justified by the fact that the Byzantine Empire was the dominant culture in early Middle Ages in the Mediterranean World. Other colourants include azurite and indigo, red lead, orpiment, red and yellow ochres, while a mixture of blue and yellow colourants, known as vergaut, was used to render green hues. Organic colourants were also used, such as madder and Tyrian purple, the latter employed to dye the parchment of Vienna Genesis.
Among the materials coming from the excavation of the Museo Egizio of Torino there is a series of... more Among the materials coming from the excavation of the Museo Egizio of Torino there is a series of funerary masks of Roman period realized by a “cartonnage” techniques. These materials needed a conservation and rebuilding process due to their bad repair [1-3].
During this restoration process a non invasive analytical study was realized using portable X-ray Fluorescence spectrometry and Raman spectroscopy. All the materials composing the different masks were measured, starting from the papyri and going on to the plaster used as glue; crossing to the colored parts that draw the so nice face image. A statistical base of the obtained results was supported by the comparison with similar materials, as ink, pigments, papyri and raw plasters.
In particular, analysis of both red and black inks and colors (red, yellow, blue and green) on different supports were performed. All the objects are ranged in a chronological window between the XI-XII and the XXIII dynasty that can be used to better define the manufacturing context of the production.
Analyzing the results a complete characterization of the painted layers and inks were succeeded; observing the presence of Egyptian blue, pararealgar, madder lake and red ochre, despite of the limitation of portable instrumentations [4,5]. We also report an interesting occurrence of titanium elements in some inks.
The research activity was realized in collaboration with the Società Cooperativa Archeologica (SCA), which is contributing to the scientific and conservative process act to the valorization of the Assiut archeological finds.
In the small mountain hamlet of Ala di Stura (Piedmont, Lanzo Valleys), a large but relatively un... more In the small mountain hamlet of Ala di Stura (Piedmont, Lanzo Valleys), a large but relatively unknown artistic heritage is present, made of 110 mural paintings divided among meridians and paintings with religious themes. These artworks are datable among XVI and XXI century. To support the work of touristic promotion carried out by the Commune of Ala di Stura, micro samples have been withdrawn from the most relevant artworks in order to execute Raman and scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis and to have useful information concerning conservation, dating and global knowledge on the artworks themselves that are little known outside Piedmont. Analyses allowed to elucidate phenomena of chromatic alteration (changing of lead pigments), to individuate pigments acting as time markers (synthetic ultramarine blue, arsenical green pigments) and to have information on the origin and exploitation of pictorial materials used by the artists who worked in Ala di Stura. Of particular interest is the fact that all pigments identified in the older paintings, and many among those identified in the newer ones, could be derived from minerals sources present in the Lanzo Valleys, among which is olivenite, a rare copper arsenate used as a green pigment that has rarely cited in the scientific literature.
Two series of printed volumes, respectively, created in Parma and in Vienna at the end of XVIII c... more Two series of printed volumes, respectively, created in Parma and in Vienna at the end of XVIII century, were analysed in order to characterise the palettes used in the hand-coloured miniatures and to determine whether decoration had been carried out simultaneously to, or shortly after, the time of printing. The application of complementary non-invasive analytical techniques allowed to yield a thorough knowledge of the colorants present and to determine that artists used a mixing of ancient, traditional materials such as cinnabar, minium or indigo, and materials of recent introduction in late XVIII century such as gamboge, Prussian blue or blue verditer. There was no evidence of colorants created successively to the age of printing, so that it can be concluded that decoration could have been done at the time of printing. Interesting is the use of metal pigments in the Vienna volumes, either in powder form and in foil form as a basis to obtain iridescence effects, a clue to evaluate the great skillfulness of the artist. Among the colorants identified, particularly relevant is the identification of gamboge, a colorant almost exclusively used among Far Eastern Asian painters according to the literature; this fact suggests that information on the use of pictorial materials can be strongly updated by diagnostic analyses.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Jan 1, 2012
The characterisation of palettes used in manuscript illumination is a hard analytical task, due t... more The characterisation of palettes used in manuscript illumination is a hard analytical task, due to value and fragility of the analysed items. Analysis on miniatures must be necessarily non-invasive and fast and requires the use of several techniques since no single technique is able to provide all information needed. In this work a four-step analytical protocol is proposed for non-invasive in situ characterisation of miniature paintings. The protocol allows the identification of coloured materials through the use in sequence of complementary techniques, so as to fully exploit the information given by each instrument. Preliminarily to the instrumental investigations on ancient books and miniatures is the compilation of spectroscopic databases obtained from “standard” samples prepared on parchment, according to recipes described in medieval artistic treatises. The protocol starts with an extensive investigation with UV–visible spectrophotometry in reflectance mode, collecting spectra from all the most significant painted areas in the manuscript; chemometric classification is then performed on the spectra to highlight areas possibly containing the same materials. The second step involves in-depth inspection of miniatures under optical microscopy that guides the interpretation of reflectance spectra. XRF spectrometry is then performed to characterise pigments and metal layers, to verify the presence of overlapping layers, to identify mordants in lakes and to recognise minor components that may yield information concerning provenance; in addition, chemometric classification can be performed on element concentrations to highlight similar areas. Finally, Raman spectroscopy is used to shed light on the uncertain cases, if still present. Such a procedure offers a wealth of information without causing stress to the manuscripts under analysis.
This work will present the results of p-XRF analysis applied in situ to three XI- XII century man... more This work will present the results of p-XRF analysis applied in situ to three XI- XII century manuscripts covers considered as masterpieces of Northern Italy medieval jewellery: the golden and silver valves of Evangeliario di Ariberto (Milano), the golden valve of Pace di Chiavenna and the golden and silver valves of Liber Evangeliorium of Vercelli binding. The golden valves show a sumptuous decoration of golden leaves, plates and filigrees, enamels and casted gems, while the silver ones, probably the covers of the case containing the manuscript, have a more simple and sober aspect, thus reflecting the different meaning and function of the two objects during the liturgy.
The aim of this research is to obtain information on manufacturing techniques and composition of the artefacts, considering possible analogies and difference which may be useful for art historians discussion on manufacture place and artistic connections. XRF analysis was performed with p-XRF in order to determine the composition of the metals and enamels, and quantitative results, obtained using certified standards, undergo data treatment with multivariate analysis. Relationship between composition and material manufacturing was clearly observed, all filigrees showing higher Cu and Ag values respect to sheets and plates. In particular, the Evangelists in Pace di Chiavenna shows the highest Au content among the golden sheets, while we underline the higher Ag contents of the central filigree round respect to the external ones, suggesting for this artefact two separate manufacturing of the filigree rounds. Analysis on Pace di Ariberto differentiated originals parts from substitutions, presenting lower Au contents, and recognized as niello the black decoration on the Christ figure. The Liber Evangeliorum cover shows a wider range of compositions for Cu-Au-Ag alloys. The silver sheets of the bottom are in fact brightly reddish because of higher Cu contents, while the golden plates show high Au contents: the resulting different and contrasting colours are used to obtain a peculiar chromatic effect.
In 1982, a sixteenth-century botanical manuscript (MS 95) was discovered in the private archives ... more In 1982, a sixteenth-century botanical manuscript (MS 95) was discovered in the private archives of the De Paoli family, in the Upper Vara Valley in the Ligurian province of La Spezia. Based on non-invasive diagnostic techniques, analysis of the watermark and iconographical comparisons, we know that the manuscript MS 95 was produced in the area between Liguria and Tuscany. This essay highlights the importance of diagnostic analysis in cases where no information exists concerning the author and the provenance of a document. The identification of the materials used in the production of this manuscript and that of the iconographical representations reveal that the anonymous author was part of a vernacular culture that consulted printed books and library manuscripts and that local pigments and materials were probably used.
ABSTRACT Around 100 porcelain objects of the 18th century Rossetti, Vische and Vinovo manufacture... more ABSTRACT Around 100 porcelain objects of the 18th century Rossetti, Vische and Vinovo manufactures (Piedmont, Italy) from the Palazzo Madama Museum collection were analysed by means of an X-ray fluorescence portable detector. The present study represents the first chemical characterization of these early (1737–1825) European porcelains. Chemical composition data were submitted to multivariate clustering techniques that underscored a complete classification of the three manufactures and the presence of three subgroups for the Vinovo production. These resulting subgroups did not mirror the classification expected on the basis of the historiographic literature. The overall data pointed to technological continuity not only through all the Vinovo phases but even continuing from the earlier Vische manufacture.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015
Folium and orchil are dyes of vegetal origin. Folium is obtained from Chrozophora tinctoria (L.) ... more Folium and orchil are dyes of vegetal origin. Folium is obtained from Chrozophora tinctoria (L.) A. Juss., whereas orchil is obtained from Roccella and other genera of lichens. These dyes were used in the past to impart purple hue to paintings and textiles as substitutes for the more prised Tyrian purple dye, obtained from shellfish. Despite several citations in ancient technical treatises dating back at least to the Greek-Roman age, the identification of these dyes in artworks is rare. In the case of folium, an additional drawback is that its composition is presently unknown. In this work different non-invasive (FT-IR, FT-Raman, fibre optic reflectance spectrophotometry, spectrofluorimetry, X-ray fluorescence spectrometry) and micro-invasive (surface enhanced Raman spectroscopy, matrix assisted laser desorption ionisation-time of flight-mass spectrometry, inductively coupled plasma-mass spectrometry) techniques were used in order to increase the diagnostic information available on these dyes. Measurements were carried out on the dyes extracted from raw materials and on painted or dyed parchments. The possibility to distinguish between folium and orchil by chemical analysis is discussed.
This paper will present portable X-ray fluorescence (pXRF) analysis applied in situ to three 11th... more This paper will present portable X-ray fluorescence (pXRF) analysis applied in situ to three 11th-12th century manuscripts covers considered as masterpieces of Northern Italy medieval jewellery: Pace di Ariberto (Milano), Liber Evangeliorium of Vercelli and Pace di Chiavenna. These objects show a sumptuous decoration of golden leaves, plates and filigrees, enamels and casted gems. The aim of this research is to obtain information on manufacturing techniques and composition of the ace and artistic connections. XRF analysis was performed in order to determine the composition of the metals and enamels, and quantitative results, obtained using certified standards, undergo data treatment with multivariate analysis. The present paper will present a part of the results obtained on both the metals and glass materials, underlying the potential of pXRF in producing reliable results also when working in non-ideal conditions.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
Two Byzantine VI century manuscripts known as Vienna Dioskurides and Vienna Genesis, held in the ... more Two Byzantine VI century manuscripts known as Vienna Dioskurides and Vienna Genesis, held in the Austrian National Library at Vienna, were analysed with in situ non-invasive techniques. Raman spectroscopy, UV–Vis diffuse reflectance spectrophotometry with optic fibres and X-ray fluorescence spectrometry were used to characterise the palette of these early Middle Ages manuscripts. The analytical study was performed to have a better knowledge on the colourants used by ancient miniature painters, a subject known more on the basis of traditional sources (i.e. medieval treatises) than of analytical evidences. Indeed these illuminated manuscripts are, to the authors’ knowledge, among the oldest ever being analysed, so that the colourants found in them can be considered among the oldest evidences of their use. The main feature of Vienna Dioskurides and Vienna Genesis palettes is their richness, exemplified by the simultaneous presence of gold and ultramarine blue; in Vienna Dioskurides cinnabar is also present. Information regarding ultramarine blue is surprising, being the analytical evidence of the use of this precious pigment at least three centuries before its use in Western manuscripts, a feature justified by the fact that the Byzantine Empire was the dominant culture in early Middle Ages in the Mediterranean World. Other colourants include azurite and indigo, red lead, orpiment, red and yellow ochres, while a mixture of blue and yellow colourants, known as vergaut, was used to render green hues. Organic colourants were also used, such as madder and Tyrian purple, the latter employed to dye the parchment of Vienna Genesis.
Among the materials coming from the excavation of the Museo Egizio of Torino there is a series of... more Among the materials coming from the excavation of the Museo Egizio of Torino there is a series of funerary masks of Roman period realized by a “cartonnage” techniques. These materials needed a conservation and rebuilding process due to their bad repair [1-3].
During this restoration process a non invasive analytical study was realized using portable X-ray Fluorescence spectrometry and Raman spectroscopy. All the materials composing the different masks were measured, starting from the papyri and going on to the plaster used as glue; crossing to the colored parts that draw the so nice face image. A statistical base of the obtained results was supported by the comparison with similar materials, as ink, pigments, papyri and raw plasters.
In particular, analysis of both red and black inks and colors (red, yellow, blue and green) on different supports were performed. All the objects are ranged in a chronological window between the XI-XII and the XXIII dynasty that can be used to better define the manufacturing context of the production.
Analyzing the results a complete characterization of the painted layers and inks were succeeded; observing the presence of Egyptian blue, pararealgar, madder lake and red ochre, despite of the limitation of portable instrumentations [4,5]. We also report an interesting occurrence of titanium elements in some inks.
The research activity was realized in collaboration with the Società Cooperativa Archeologica (SCA), which is contributing to the scientific and conservative process act to the valorization of the Assiut archeological finds.
In the small mountain hamlet of Ala di Stura (Piedmont, Lanzo Valleys), a large but relatively un... more In the small mountain hamlet of Ala di Stura (Piedmont, Lanzo Valleys), a large but relatively unknown artistic heritage is present, made of 110 mural paintings divided among meridians and paintings with religious themes. These artworks are datable among XVI and XXI century. To support the work of touristic promotion carried out by the Commune of Ala di Stura, micro samples have been withdrawn from the most relevant artworks in order to execute Raman and scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis and to have useful information concerning conservation, dating and global knowledge on the artworks themselves that are little known outside Piedmont. Analyses allowed to elucidate phenomena of chromatic alteration (changing of lead pigments), to individuate pigments acting as time markers (synthetic ultramarine blue, arsenical green pigments) and to have information on the origin and exploitation of pictorial materials used by the artists who worked in Ala di Stura. Of particular interest is the fact that all pigments identified in the older paintings, and many among those identified in the newer ones, could be derived from minerals sources present in the Lanzo Valleys, among which is olivenite, a rare copper arsenate used as a green pigment that has rarely cited in the scientific literature.
Two series of printed volumes, respectively, created in Parma and in Vienna at the end of XVIII c... more Two series of printed volumes, respectively, created in Parma and in Vienna at the end of XVIII century, were analysed in order to characterise the palettes used in the hand-coloured miniatures and to determine whether decoration had been carried out simultaneously to, or shortly after, the time of printing. The application of complementary non-invasive analytical techniques allowed to yield a thorough knowledge of the colorants present and to determine that artists used a mixing of ancient, traditional materials such as cinnabar, minium or indigo, and materials of recent introduction in late XVIII century such as gamboge, Prussian blue or blue verditer. There was no evidence of colorants created successively to the age of printing, so that it can be concluded that decoration could have been done at the time of printing. Interesting is the use of metal pigments in the Vienna volumes, either in powder form and in foil form as a basis to obtain iridescence effects, a clue to evaluate the great skillfulness of the artist. Among the colorants identified, particularly relevant is the identification of gamboge, a colorant almost exclusively used among Far Eastern Asian painters according to the literature; this fact suggests that information on the use of pictorial materials can be strongly updated by diagnostic analyses.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Jan 1, 2012
The characterisation of palettes used in manuscript illumination is a hard analytical task, due t... more The characterisation of palettes used in manuscript illumination is a hard analytical task, due to value and fragility of the analysed items. Analysis on miniatures must be necessarily non-invasive and fast and requires the use of several techniques since no single technique is able to provide all information needed. In this work a four-step analytical protocol is proposed for non-invasive in situ characterisation of miniature paintings. The protocol allows the identification of coloured materials through the use in sequence of complementary techniques, so as to fully exploit the information given by each instrument. Preliminarily to the instrumental investigations on ancient books and miniatures is the compilation of spectroscopic databases obtained from “standard” samples prepared on parchment, according to recipes described in medieval artistic treatises. The protocol starts with an extensive investigation with UV–visible spectrophotometry in reflectance mode, collecting spectra from all the most significant painted areas in the manuscript; chemometric classification is then performed on the spectra to highlight areas possibly containing the same materials. The second step involves in-depth inspection of miniatures under optical microscopy that guides the interpretation of reflectance spectra. XRF spectrometry is then performed to characterise pigments and metal layers, to verify the presence of overlapping layers, to identify mordants in lakes and to recognise minor components that may yield information concerning provenance; in addition, chemometric classification can be performed on element concentrations to highlight similar areas. Finally, Raman spectroscopy is used to shed light on the uncertain cases, if still present. Such a procedure offers a wealth of information without causing stress to the manuscripts under analysis.
This work will present the results of p-XRF analysis applied in situ to three XI- XII century man... more This work will present the results of p-XRF analysis applied in situ to three XI- XII century manuscripts covers considered as masterpieces of Northern Italy medieval jewellery: the golden and silver valves of Evangeliario di Ariberto (Milano), the golden valve of Pace di Chiavenna and the golden and silver valves of Liber Evangeliorium of Vercelli binding. The golden valves show a sumptuous decoration of golden leaves, plates and filigrees, enamels and casted gems, while the silver ones, probably the covers of the case containing the manuscript, have a more simple and sober aspect, thus reflecting the different meaning and function of the two objects during the liturgy.
The aim of this research is to obtain information on manufacturing techniques and composition of the artefacts, considering possible analogies and difference which may be useful for art historians discussion on manufacture place and artistic connections. XRF analysis was performed with p-XRF in order to determine the composition of the metals and enamels, and quantitative results, obtained using certified standards, undergo data treatment with multivariate analysis. Relationship between composition and material manufacturing was clearly observed, all filigrees showing higher Cu and Ag values respect to sheets and plates. In particular, the Evangelists in Pace di Chiavenna shows the highest Au content among the golden sheets, while we underline the higher Ag contents of the central filigree round respect to the external ones, suggesting for this artefact two separate manufacturing of the filigree rounds. Analysis on Pace di Ariberto differentiated originals parts from substitutions, presenting lower Au contents, and recognized as niello the black decoration on the Christ figure. The Liber Evangeliorum cover shows a wider range of compositions for Cu-Au-Ag alloys. The silver sheets of the bottom are in fact brightly reddish because of higher Cu contents, while the golden plates show high Au contents: the resulting different and contrasting colours are used to obtain a peculiar chromatic effect.
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Papers by Gaia Fenoglio
During this restoration process a non invasive analytical study was realized using portable X-ray Fluorescence spectrometry and Raman spectroscopy. All the materials composing the different masks were measured, starting from the papyri and going on to the plaster used as glue; crossing to the colored parts that draw the so nice face image. A statistical base of the obtained results was supported by the comparison with similar materials, as ink, pigments, papyri and raw plasters.
In particular, analysis of both red and black inks and colors (red, yellow, blue and green) on different supports were performed. All the objects are ranged in a chronological window between the XI-XII and the XXIII dynasty that can be used to better define the manufacturing context of the production.
Analyzing the results a complete characterization of the painted layers and inks were succeeded; observing the presence of Egyptian blue, pararealgar, madder lake and red ochre, despite of the limitation of portable instrumentations [4,5]. We also report an interesting occurrence of titanium elements in some inks.
The research activity was realized in collaboration with the Società Cooperativa Archeologica (SCA), which is contributing to the scientific and conservative process act to the valorization of the Assiut archeological finds.
Talks by Gaia Fenoglio
The aim of this research is to obtain information on manufacturing techniques and composition of the artefacts, considering possible analogies and difference which may be useful for art historians discussion on manufacture place and artistic connections. XRF analysis was performed with p-XRF in order to determine the composition of the metals and enamels, and quantitative results, obtained using certified standards, undergo data treatment with multivariate analysis. Relationship between composition and material manufacturing was clearly observed, all filigrees showing higher Cu and Ag values respect to sheets and plates. In particular, the Evangelists in Pace di Chiavenna shows the highest Au content among the golden sheets, while we underline the higher Ag contents of the central filigree round respect to the external ones, suggesting for this artefact two separate manufacturing of the filigree rounds. Analysis on Pace di Ariberto differentiated originals parts from substitutions, presenting lower Au contents, and recognized as niello the black decoration on the Christ figure. The Liber Evangeliorum cover shows a wider range of compositions for Cu-Au-Ag alloys. The silver sheets of the bottom are in fact brightly reddish because of higher Cu contents, while the golden plates show high Au contents: the resulting different and contrasting colours are used to obtain a peculiar chromatic effect.
During this restoration process a non invasive analytical study was realized using portable X-ray Fluorescence spectrometry and Raman spectroscopy. All the materials composing the different masks were measured, starting from the papyri and going on to the plaster used as glue; crossing to the colored parts that draw the so nice face image. A statistical base of the obtained results was supported by the comparison with similar materials, as ink, pigments, papyri and raw plasters.
In particular, analysis of both red and black inks and colors (red, yellow, blue and green) on different supports were performed. All the objects are ranged in a chronological window between the XI-XII and the XXIII dynasty that can be used to better define the manufacturing context of the production.
Analyzing the results a complete characterization of the painted layers and inks were succeeded; observing the presence of Egyptian blue, pararealgar, madder lake and red ochre, despite of the limitation of portable instrumentations [4,5]. We also report an interesting occurrence of titanium elements in some inks.
The research activity was realized in collaboration with the Società Cooperativa Archeologica (SCA), which is contributing to the scientific and conservative process act to the valorization of the Assiut archeological finds.
The aim of this research is to obtain information on manufacturing techniques and composition of the artefacts, considering possible analogies and difference which may be useful for art historians discussion on manufacture place and artistic connections. XRF analysis was performed with p-XRF in order to determine the composition of the metals and enamels, and quantitative results, obtained using certified standards, undergo data treatment with multivariate analysis. Relationship between composition and material manufacturing was clearly observed, all filigrees showing higher Cu and Ag values respect to sheets and plates. In particular, the Evangelists in Pace di Chiavenna shows the highest Au content among the golden sheets, while we underline the higher Ag contents of the central filigree round respect to the external ones, suggesting for this artefact two separate manufacturing of the filigree rounds. Analysis on Pace di Ariberto differentiated originals parts from substitutions, presenting lower Au contents, and recognized as niello the black decoration on the Christ figure. The Liber Evangeliorum cover shows a wider range of compositions for Cu-Au-Ag alloys. The silver sheets of the bottom are in fact brightly reddish because of higher Cu contents, while the golden plates show high Au contents: the resulting different and contrasting colours are used to obtain a peculiar chromatic effect.