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1.
《文物保护研究》2013,58(3):199-210
Abstract

Descente des vaches (1836) by Théodore Rousseau in the Mesdag Collection in The Hague is barely readable and its paint layers are in poor condition. The surface of the painting is strongly deformed and cracked, the whole painting has darkened and especially the greens have lost all or most of their colour resulting in brown passages. Large passages of the painting that were painted with multiple thick and medium-rich layers have darkened dramatically. This paper proposes that the degradation of Emerald green (Cu(C2H3O2)2·3Cu(AsO2)2, copperacetoarsenite) – the main green pigment used in this painting – is a significant factor in the cause of the darkening. Electron backscatter images reveal that the Emerald green particles are shown different degrees of degradation: from partially to completely disintegrated. Elemental maps show that arsenic is distributed throughout the paint cross section, with relatively higher concentrations around iron- and aluminium-containing particles, and in the varnish layer. Imaging-Fourier-transform infrared microscopy detects copper soaps in the degraded Emerald green-containing layers. Analytical data from four paint cross sections strongly suggest that Emerald green reacts with free fatty acids derived from the binding medium forming copper soaps and mobile arsenic-based species. Chemical laboratory experiments fully support this hypothesis. Emerald green and palmitic acid in chloroform form copper palmitate and arsenic trioxide (arsenolite, cubic) under room temperature and normal light conditions. The degradation of Emerald green particles in Descente des vaches has resulted in a loss of light-reflecting surfaces and in newly formed compounds in the paint, both contribute to the colour change from green to brown.  相似文献   

2.
《文物保护研究》2013,58(3):183-186
Abstract

A yellowish copper vanadate mineral has been found in Swedish mural paintings from the fifteenth century. Small patches occur in malachite-green paint. Thirteen samples from five churches have been analyzed by optical and scanning electron microscopy with energy–dispersive X-ray spectrometry, transmission electron microscopy, X-ray powder diffraction, and polarized light microscopy. The substance is evidently the rather uncommon mineral volborthite, with the chemical formula Cu3V2O7(OH)2.2H2O. Very small quantities have also been noted for another mineral, presumably calcio-volborthite, CaCu(VO4)(OH), also named tangeite. The results show that the conservator should always be observant for pigments not earlier noticed or reported. There are some old mines in Central Europe, e.g. in Germany, which contain malachite as well as copper vanadate minerals, and this is probably the origin of the yellow patches in the paintings.  相似文献   

3.
4.
Nine ancient Egyptian sarcophagi of the twenty-fifth to twenty-sixth dynasty, one Ptolemaic Hawk Mummy, and one Amarna fresco were examined in the collections of the San Diego Museum of Man. Binding media, pigments, wood identification, deterioration and alteration products were identified. The pigment palette represents the basic suite of ancient Egyptian pigments: charcoal black, red ochre, yellow ochre, Egyptian blue, green earth, calcite, and gypsum. In the case of the Hawk mummy, oxammite was identified as a degradation product, together with magnesium phosphate, the first identification of oxammite in ancient artefacts. In a child’s coffin, realgar and orpiment were additionally identified. The binding media for practically all of the coffins studied was confirmed as gum Arabic with only one example of gum tragacanth found from a wall plaque from Amarna. Wood identification showed that Ficus sycomorus had been used, rather than the assumed cedar of Lebanon for coffin manufacture. One unidentified species of shrubby wood was also found. Some of the coffins had been restored, with one having a completely repainted face, in rutile, and the child’s coffin has an attached foot-box with modern screws. Possible indications of ancient reuse were found during the study.  相似文献   

5.
《文物保护研究》2013,58(3):117-122
Abstract

Samples of pigments from a wall-painting of a house of the first Pompeian style (400 Bc–168 BC) found in Pella, Greece, were analyzed by the non-destructive methods of X-ray fluorescence and X-ray diffraction. Red pigments were identified as cinnabar and iron oxide pigments (haematite and goethite). Blue was the well-known Egyptian blue and yellow was identified as goethite. A characteristic feature of the wall-painting was the presenceof green earth, i.e. celadonite and glauconite, encountered for the first time in this series of investigations.  相似文献   

6.
ABSTRACT

This article presents historical and scientific analysis, as well as the conservation treatment of a newly rediscovered Roman wall painting fragment, now in the collection of the Harvard Art Museums. Although the piece has not previously been published, it was among a group of fragments removed from a Roman villa near Boscotrecase in southern Italy, an area that has been key to the study of Roman wall painting and other decoration. Technical imaging confirms the use of painting techniques consistent with other high-quality paintings in the area. Materials analysis revealed a palette consistent with published findings of Roman wall paintings, including abundant use of Egyptian blue and green earth. Of interest was the use of Egyptian blue as an optical brightener in select white passages. Despite the high quality of the painting, no cinnabar was present, and all red passages were achieved using hematite. Multiple different white minerals were identified including calcite, aragonite, and gypsum. The widespread presence of gypsum is unusual and may point to alteration.  相似文献   

7.
ABSTRACT

Composition, microstructure, and binding media of the decorative earthen plaster fragments from the Buddhist cave temple of Bezeklik (fifth–fourteenth century CE), China, were analyzed by X-ray fluorescence, X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, Fourier-transform infrared spectroscopy, sieve analysis, and other methods. In addition, gas chromatography–mass spectrometry was used for identification of the organic adhesive found mixed in the earthen plaster. Studies indicated the presence of proteinaceous material, mainly beeswax, with animal glue, pine resin, and plant sterol mixed in the earthen plaster as the biopolymer. The organic additives improved the basic qualities of the mud by acting as stabilizers, hardeners, and water proofers. The loamy sand soil sourced for Bezeklik plasters shows low cohesion and disaggregation of grains occurred for want of clay-sized particles in the plaster. Due to frequent handling and transportation, the fragments are now showing distress in the form of loss of earthen support and paint layers. Based on the analytical findings, traditional binders such as sepiolite clay, slaked lime, and fish glue were introduced and fragments consolidated for display.  相似文献   

8.
《文物保护研究》2013,58(1):22-26
Abstract

Very small paint samples from Cosimo Tura's ‘The Annunciation with Saint Francis and Saint Louis of Toulouse’ were submitted to amino acid analysis in order to determine the nature of the binding media. The four panels appeared to have been painted with egg tempera, and showed extensive localized deterioration in the blue areas but not in the other coloured areas. Following the Picotag method, the samples were hydrolyzed in an acid vapor, derivatized with iso-thiocyanatobenzene, and analyzed using reversed phase high pressure liquid chromatography (HPLC). Amino acid analysis demonstrated that the red and brown areas were painted using egg yolk as the binding medium, while the blue areas were painted with animal-skin glue (distemper). Analysis of the green paint indicated a mixture of egg yolk and glue. The use of these techniques makes it possible to identify proteinaceous materials in art objects from samples in the microgram range.  相似文献   

9.
《文物保护研究》2013,58(3):107-119
Abstract

Samples of pigments from excavated wall-paintings at the great civilization center of the Greek Bronze Age, Thera, have been analysed by the non-destructive methods of X-ray fluorescence, X-ray diffraction and mineralogical microscopic examination. The results showed that three types of blue pigment were used, namely the well-known Egyptian blue, glaucophane, which is a sodium magnesium (or iron) aluminium hydroxide silicate which occurs as a natural mineral on Santorini, and a mixture of Egyptian blue and glaucophane. Black pigments were rather puzzling in that some of them are carbon as expected, and some are manganese compounds. The rest of the pigments are very similar to those previously examined from Mycenae and Knossos.  相似文献   

10.
ABSTRACT

Mechanical properties of aged beeswax were studied by an indirect measurement, using hydrogenated beeswax as a model material. The adequacy of the model was evaluated by comparison of its chemical composition and thermal properties with those of samples of historical beeswax. It was found that the gradual decrease in content of unsaturated compounds in beeswax contributes significantly to changes of its mechanical properties. As a consequence, beeswax artefacts become increasingly prone to mechanical damage during natural ageing. Understanding the difference between mechanical properties of recent and historical beeswax is primarily important from the point of view of safe handling and storage of such artefacts. Besides, this knowledge could help conservation scientists, e. g. when preparing model samples for testing new conservation methods.  相似文献   

11.
《文物保护研究》2013,58(3):34-40
Abstract

In preparation for a major exhibition at the National Gallery of Scotland in 2005, a thorough technical examination of VISION OF THE SERMON by Paul Gauguin was undertaken for the first time since the painting's acquisition in 1925. An inter-disciplinary approach to the research was adopted in an attempt to assess how innovative were the materials and techniques employed by Gauguin in this iconic work. The importance of the unique customs and religious piety of Brittany in 1888 to the iconography of Vision is discussed, as well as the various ways in which the original appearance of the painting has altered over time. Changes have occurred through both the natural ageing of materials and as a result of human intervention, particularly an aqueous lining and reframing. Analysis suggests that the paint medium consists of several different drying oils, confounding years of speculation that it may contain wax. The discovery that the original surface coating contains beeswax and tallow has grave implications for the feasibility of future conservation treatments. Following Gauguin's accusation of plagiarism by Emile Bernard, a tentative comparison is made between Vision and the latter's Breton Women in the Meadow. This reveals that while compositional similarities exist, Vision is far more complex, both in conception and execution.  相似文献   

12.
Pigments on a figurative wall painting in Poudeh village, central Iran, were analysed by micro X-ray fluorescence spectrometry, micro Raman spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectrometry, micro Fourier transform infrared spectroscopy, X-ray diffractometry, and polarised light microscopy. Red lead, ultramarine blue, chrome yellow, brass powder, white huntite, and lammerite (Cu3(AsO4)2) were identified as red, blue, yellow, golden, white, and green pigments, respectively, while gypsum and barite were used as extender. In addition, glushinskite (MgC2O4·2H2O) was identified as a deterioration product of white huntite. Moreover, several analytical studies suggested that lammerite was a degradation product of emerald green (Cu(CH3COO)2·3Cu(AsO2)2) originally used as green pigment in the painting. The formation of lammerite is suggested to be due to the migration of arsenic throughout the paint layer. Based on the pigments identified, the wall painting is dated from the mid-nineteenth century to the mid-twentieth century.  相似文献   

13.
《文物保护研究》2013,58(4):264-272
Abstract

The removal of calcareous accretions from archaeological bronzes can be a difficult step in their conservation. Chemical cleaning with chelating agents might be an alternative to mechanical methods. In this study the use of the chelating agent sodium tripolyphosphate (STPP) was examined to determine whether it is effective in discriminating between calcium carbonate and copper patina, and non-corrosive to copper alloys in the presence of air. Comparative experiments with STPP and disodium ethylenediamine-tetraacetate (Na2-EDTA) were carried out on synthetic malachite, cuprite, calcium carbonate, naturally polished malachite surfaces and sheets of bronze and brass. In addition to the properties of the chelating agent, the solubility of the salts and the pH values of the solutions are crucial factors in the removal of compounds of low solubility. The quantity of metal ions dissolved, estimated by atomic absorption spectral analysis and scanning electron microscopy, showed that the calcareous accretions could be removed satisfactorily, but STPP also dissolved constituent parts of the patina, such as malachite and cuprite, and may harm bronze or brass. Compared to Na2-EDTA, STPP is less effective in dissolving calcium carbonate. It is less harmful to the patina and base metal, but may lead to patination of the underlying metal.  相似文献   

14.
《文物保护研究》2013,58(3):226-244
Abstract

This study describes the examination and analysis of four mixed media paintings from the 1960s and 1970s by Canadian artist Jack Chambers (1931–1978). The documentary evidence about his materials and methods is summarized and compared with the results of analysis of multilayer paint samples. The combination of Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) allowed the components of the paint media to be characterized: ortho-phthalate alkyd resins, iso-phthalate alkyd resins, drying oils, dammar, Pinaceae resin, and turpentine were identified in varying proportions. Many pigments and fillers were identified by FTIR and Raman and are enumerated. The effect that Chambers’ complex technique has had on the aging and degradation of the paintings is discussed. The severe cracking of the paint layers in one of the four paintings may be the result of a high proportion of dammar and turpentine diluent mixed with the alkyd paint and may also be related to the type of alkyd resin medium. Different history and environmental conditions may also be factors.  相似文献   

15.
Copper trihydroxychloride [Cu2Cl(OH)3] exists with four polymorphs: atacamite, paratacamite, clinoatacamite, and botallackite. They have all been used as green pigments, usually under the name atacamite. For many years, atacamite was regarded as a pigment mainly used in ancient South America, China, and Egypt. However, the last decades have shown that atacamite has been found in European medieval paintings, and quite often in Sweden. This paper gives a brief overview of the history of atacamite and its polymorphs. Green pigments from medieval murals in 56 Swedish churches were analyzed. The results show that atacamite and malachite are common, while green earth is less frequent and green vivianite rare. In particular, atacamite often occurs in medieval wall paintings on the island of Gotland in the Baltic Sea. The atacamite minerals are rare in Europe and are not found in the Swedish bedrock. Their occurrence in Swedish murals and their origin is discussed. Atacamite may be synthesized by various methods and is in fact often observed on corroded outdoor bronze statues in marine surroundings.  相似文献   

16.
《文物保护研究》2013,58(4):145-161
Abstract

For the study of Italian paintings and their techniques the examination of the binding media (glue, egg, oil) has considerable importance, but with the usual scientific methods of analysis the results have never been conclusive. Each sample may include more than one layer of paint and many constituents; egg yolk alone contains protein, oils, cholesterol. In the present project, in order to identify these diverse materials and also to eliminate interference from contamination (glue, wax or oil) used in later restoration processes, it was decided to mount original paint samples, including a bit of the ground, as cross-sections in a polyester resin embedding material and then to make the constituents visible under the microscope by using selective staining techniques. Only in this way could the foreign materials be distinguished from the original and the structure of the original layers be understood. Finally, other tests such as the fluorescent antibody technique and thin-layer chromatography could be applied to confirm the results of the staining. In removing over 500 specimens fronl paintings in the Walters Art Gallery precautions were taken to assure sample authenticity, and during the testing at the University of Michigan careful methods of standardization and control were devised, using both fresh and old samples of egg tempera and oil. Two stains, Ponceau S for protein and Sudan Black B for oil, provided the most workable means of identifying the binding media in the majority of the samples studied. A final report will have to await correlation of the material, but certain observations may be made at this stage: (a) 14th century, in primarily tempera paintings a limited use of oil was found associated with a specific green pigment, copper resinate; (b)15th century, the majority of the paintings were entirely of egg tempera, but layers containing oil in the underpainting or in the above-mentioned copper green occurred more frequently; (c)16th century, egg tempera was not replaced by oil, but both were used in a complex layering technique, the media varying layer by layer and area by area; (d)17th century, the mixed technique gradually declined, but egg tempera continued to be associated with the painting of flesh and occasional highlights.  相似文献   

17.
《文物保护研究》2013,58(4):149-154
Abstract

The small areas of white metallic pigment seen on the south wall of J. M. Whistler's ‘Peacock Room’ in the Freer Gallery of Art are platinum; this has been used, with a yellow-brown ground, to overpaint a preceding layer of silver which, in one place only, is over a preceding layer of gold. The yellow metallic pigment is confirmed as gold and the blue colour of the south wall and elsewhere is based on Prussian blue. On a separate wood panel a green was tentatively identified as copper resinate, and iron-oxide-based pigments appear to be present. In all areas investigated a white, used as a ground and in admixture, was essentially lead white and calcium carbonate. The significance of these results is discussed briefly.  相似文献   

18.
《文物保护研究》2013,58(2):54-61
Abstract

Samples of pigments from excavated wall paintings of Vergina’s second tomb were analyzed by the non-destructive methods of X-ray fluorescence, X-ray diffraction and mineralogical microscopic examinations. The results showed that one type of blue pigment was used, the well-known Egyptian blue. The red pigments, except one which is haematite, are cinnabar (HgS), and the grey pigments are carbon. None of the black pigments contained manganese compounds.  相似文献   

19.
《文物保护研究》2013,58(3):212-222
Abstract

It is still unclear why some of the blue enamel on sixteenth- and seventeenth-century stained window glass is flaking off, while enamel layers with other colours are still in relatively good condition. In order to obtain a better understanding of this conservation problem, 31 historical recipes used for the fabrication of blue enamel were compared with results from the chemical analysis of 25 historic samples. The chemical composition and the microstructure of the enamels were analysed in cross-section by means of electron probe microanalysis (EPMA). This study demonstrated that the variation in chemical composition of the samples can be explained by the use of the wide range of recipes existing at that time. Although this study gave an insight into the composition, heterogeneity and use of colouring substances, no clear relation could be found between the parameters analysed and the deterioration rate of the blue enamel paint layer.  相似文献   

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