Ordine coloniale e stato nazionale: rapporto simmetrico?

Gironda V. Ordine coloniale e stato nazionale: rapporto simmetrico? In: Gironda V, Nani M, Petrungaro S, eds. Imperi coloniali. Italia, Germania e la costruzione del mondo coloniale. Gli alberi. Vol 71. Napoli: L'ancora del Mediterraneo ; 2009: 17-34

Imperi coloniali. Italia, Germania e la costruzione del mondo coloniale

Nani M, Petrungaro S, Gironda V, eds. Imperi coloniali. Italia, Germania e la costruzione del mondo coloniale. Modena: L'ancora del Mediterraneo ; 2009

Distinguer les vraies porcelaines impériales de la Dynastie Qing de leurs répliques anciennes par spectroscopies non-invasives de fluorescence des rayons X et Raman

International audience: The combined use of non-invasive on-site portable techniques, Raman microscopy and X-ray fluorescence spectroscopy, on seven imperial bowls and two decorated dishes, attributed to the reigns of the Kangxi, Yongzheng, Qianlong, and Daoguang emperors (Qing Dynasty), allows identifying the coloring agents/opacifiers and composition types of the glazes and painted enamels. Particular attention is paid to the analysis of the elements used in the (blue) marks and those found in the blue, yellow, red, and honey/gilded backgrounds on which or in reserve, a floral motif is principally drawn. The honey-colored background is made with gold nanoparticles associated with a lead- and arsenic-based flux. One of the red backgrounds is also based on gold nanoparticles, the second containing copper nanoparticles, both in lead-based silicate enamels like the blue and yellow backgrounds. Tin and arsenic are observed but cassiterite (SnO2) is only clearly observed in one of the painted decors (dish) and in A676 yellow whereas lead(calcium/potassium) arsenate is iden-tified in most of the enamels. Yellow color is achieved with Pb-Sn-Sb pyrochlore (Naples yellow) with various Sb content although green color is mainly based on lead-tin oxide mixed with blue enamel. The technical solutions appear very different from one object to another, which leads one to think that each bowl is really a unique object and not an item produced in small series. The visual examination of some marks shows they are made in overglaze (A608, A616, A630, A672). It is obvious that different types of cobalt sources are used for the imprinting of the marks: cobalt rich in manganese for bowl A615 (Yongzheng reign), cobalt rich in arsenic for bowl A613 (but not the blue mark), cobalt with copper (A616), and cobalt rich in arsenic and copper (A672). So, we have a variety of cobalt sources/mixtures. The high purity of cobalt used for A677 bowl indicates a pro-duction after ~1830-1850

A non-invasive on-site Raman and pXRF study of the pigments and glassy matrix of 17th-18th century enamelled French watches

International audiencePainted enamelling technique on watches as a new form of fine art emerged circa 1630 in France. This study reports the on-site characterization of twelve enamelled watches dating to the 17th and 18th centuries from the collections of Musée du Louvre in Paris. Due to the rareness and high quality of the artefacts, analyses were carried out with a non-invasive approach by mobile Raman microspectroscopy and partially by pXRF. The enamels were found to contain pigments such as Naples Yellow pyrochlore, hematite, carbon, lapis lazuli, arsenic sulphide, manganese oxides and opacifiers such as cassiterite and lead arsenate. Lead-rich silicate compositions were identified for the corresponding glassy matrix of the enamels. An interesting outcome is that different hues of the enamels had been obtained by mixing many colouring agents, rather than using pure pigments as in the case of Limoges enamelled objects. The characteristic Raman signature of lead arsenate apatite detected in some of the 17th century blue enamels is related to the use of arsenic-rich European cobalt ores, as also characterized in the blue areas of French (soft-paste) porcelain decors and high quality Limoges enamels for the same period [1-3]. The presence of colloidal gold (Au° nanoparticles) was also indirectly detected by Raman analysis in the red-related areas of the 18th century watches. At least, three types of Naples Yellow pigment were identified with Sb-rich, Sn-rich and mixed compositions [4]. [1] Ph. Colomban, L. Arberet, B. Kırmızı, On-site Raman analysis of 17th and18th century Limoges enamels: Implications on the European cobalt sources and the technological relationship between Limoges and Chinese enamels, Ceram. Int. 43 [13] (2017) 10158-10165.[2] Ph. Colomban, T.-A. Lu, V. Milande, Non-invasive on-site Raman study of blue-decorated early soft-paste porcelain: the use of arsenic-rich (European) cobalt ores – Comparison with huafalang Chinese porcelains, Ceram. Int. 44 [8] (2018) 9018-9026. [3] Ph. Colomban, M. Maggetti, A. d’Albis, Non-invasive Raman identification of crystalline and glassy phases in a 1781 Sèvres Royal Factory soft paste porcelain plate, J. Eur. Ceram. Soc. 38 [15] (2018) 5228-5233. [4] Ph. Colomban, B. Kırmızı, C. Gougeon, M. Gironda, C. Cardinal, Pigments and glassy matrix of the 17th-18th century enamelled French watches: A non-invasive on-site Raman and pXRF study, J. Cult. Herit. (2020) in press

The Enamels of the First (Soft-paste) European Blue-and-white Porcelains: Rouen, Saint-Cloud and Paris Factories: Complementarity of Raman and X-ray Fluorescence analyses with Mobile Instruments to identify the cobalt ore.

International audienceThe first porcelains made in Europe during the 17 th century and the very beginning of the 18 th century, i.e. before the discovery of kaolin in Saxony (Germany), are rare and technical analyses very limited. In contrast with Meissen Böttger porcelain based on kaolin, these porcelains are made with sand and 'chymie', like Ottoman fritware. A selection of the blue-and-white artefacts belonging to the French national collection is analyzed on-site with mobile pXRF and Raman setups: two were assigned to the Poterat Factory at Rouen, three to the Saint-Cloud Factory and two to the Pavie Factory (Paris). Three types of enamels are identified, lead-rich (as expected) but also two different lead-alkaline-earth-alkali enamels, one artefact being covered both with lead-rich and lead-poor enamel. The polymerisation index deduced from the relative intensity of SiO 4 bending and stretching bands indicates different temperatures of firing. Tin is detected in most of the enamels by XRF but cassiterite opacification is only observed for the Pavie factory artefacts. Arsenic is detected in the blue areas due to the use of European cobalt ores. Comparison of trace and minor elements as well as the type of enamel used suggest that the pot assigned to the Rouen factory fits much better with a production from the Saint-Cloud factory. The two porcelains assigned to the Pavie factory exhibit similar XRF and Raman signatures that support the attribution based on visual criteria. Combination of the mobile non-invasive XRF and Raman instruments may allow the reliable classification of artefacts on-site. Raman scattering is very efficient to detect (on-site) As-based minor phases

pXRF Data Evaluation Methodology for On-Site Analysis of Precious Artifacts: Cobalt Used in the Blue Decoration of Qing Dynasty Overglazed Porcelain Enameled at Customs District (Guangzhou), Jingdezhen and Zaobanchu (Beijing) Workshops

In a noninvasive determination, Raman and XRF analyses showed the possibility of identifying specific phases and elements characteristic of the use of recipes and ingredients imported from Europe, according to the information documented in Chinese and European archives. Two sets of objects, supposed to have been produced during the Qing Dynasty (1662–1912) at the Forbidden City (‘imperial bowls’ of the Baur Foundation, Geneva) and in the customs district of Guangzhou (Musée Ariana, Geneva), were analyzed with pXRF and also for some objects with Raman microspectroscopy also on-site. The heterogeneity of the colored zones, in three spatial directions, requires the development of a new methodology. We focused particular attention on the cobalt used in the colored areas and marks, drawn either on the body layer (standard underglaze) or on the glaze itself (overglaze). Comparison is made with previous data on Chinese and Vietnamese porcelains from the Yuan (1271–1368) and Ming Dynasty (1368–1644) periods. Combined data for objects attributed to Guangzhou from the Kangxi and Yongzheng periods indicates the use of the same raw materials containing cobalt, associated with arsenic, nickel, zinc, copper and bismuth, according to the European sources. Similarity of the glaze composition and impurities promotes the production of the glazed body with the same raw materials as those used at Jingdezhen. A consistent shift in data for Qianlong style items, which are significantly richer in manganese, is compatible with their partial mixing with Asian cobalt. The deliberate selection of conflicting objects—namely, examples belonging to the other places of production or different periods—are well-observed outside the ‘Guangzhou’ cluster. Some artifacts have anachronistic purity characteristics that support a production after ca. 1850. For instance, two objects on which certain attributions had been made concerning the stylistic analysis are definitive examples of ceramics using a refined ‘cobalt’, and therefore now may be assigned to the later production period of the first half of the 19th century

Material Characterisation of William Burges’ Great Bookcase within the Disruption of a Global Pandemic

This contribution presents the results of a technical investigation on the pigments of William Burges’ Great Bookcase (1859–62), preserved at the Ashmolean Museum. It is the first thorough material investigation of a remarkable piece of Gothic Revival painted furniture, notably an artwork by Burges, whose work has so far received little attention from a technical point of view. This study was developed during the Covid-19 pandemic, which significantly affected the planned research activities since the investigation relied extensively on collaborations with institutions within and beyond the University of Oxford. The disruption caused by the lockdown and other restrictions went far beyond any prediction and led us to redefine the project’s outcome and methodology ‘on the fly’ while maintaining its overall vision. However, thanks to the timeliness of a substantial research grant received from the Capability for Collection Fund (CapCo, Art and Humanities Research Council), we could ultimately turn this research into a unique opportunity to test the potential of recently acquired instruments, namely the Opus Apollo infrared camera and the Bruker CRONO XRF mapping spectrometer. Therefore, besides reporting on the findings, this contribution outlines the strategy adopted and assesses the new equipment’s capability for the non-invasive analysis of complex polychromies

pXRF Data Evaluation Methodology for On-Site Analysis of Precious Artifacts: Cobalt Used in the Blue Decoration of Qing Dynasty Overglazed Porcelain Enameled at Customs District (Guangzhou), Jingdezhen and Zaobanchu (Beijing) Workshops

In a noninvasive determination, Raman and XRF analyses showed the possibility of identifying specific phases and elements characteristic of the use of recipes and ingredients imported from Europe, according to the information documented in Chinese and European archives. Two sets of objects, supposed to have been produced during the Qing Dynasty (1662–1912) at the Forbidden City (‘imperial bowls’ of the Baur Foundation, Geneva) and in the customs district of Guangzhou (Musée Ariana, Geneva), were analyzed with pXRF and also for some objects with Raman microspectroscopy also on-site. The heterogeneity of the colored zones, in three spatial directions, requires the development of a new methodology. We focused particular attention on the cobalt used in the colored areas and marks, drawn either on the body layer (standard underglaze) or on the glaze itself (overglaze). Comparison is made with previous data on Chinese and Vietnamese porcelains from the Yuan (1271–1368) and Ming Dynasty (1368–1644) periods. Combined data for objects attributed to Guangzhou from the Kangxi and Yongzheng periods indicates the use of the same raw materials containing cobalt, associated with arsenic, nickel, zinc, copper and bismuth, according to the European sources. Similarity of the glaze composition and impurities promotes the production of the glazed body with the same raw materials as those used at Jingdezhen. A consistent shift in data for Qianlong style items, which are significantly richer in manganese, is compatible with their partial mixing with Asian cobalt. The deliberate selection of conflicting objects—namely, examples belonging to the other places of production or different periods—are well-observed outside the ‘Guangzhou’ cluster. Some artifacts have anachronistic purity characteristics that support a production after ca. 1850. For instance, two objects on which certain attributions had been made concerning the stylistic analysis are definitive examples of ceramics using a refined ‘cobalt’, and therefore now may be assigned to the later production period of the first half of the 19th century