Bodies and Glazes of Architectural Ceramics from the Ilkhanid Period at Takht-e Soleyman (North-Western Iran)

Bodies and glazes of tiles from the Ilkhanid period found at the UNESCO World Heritage site of Takht-e Soleyman were studied to identify materials and certain technical characteristics of the architectural ceramics as part of a larger project to establish different productions. In addition, ceramic vessels and technical ceramics excavated at the site were analysed for comparison. µXRF, SEM/EDX, and Raman spectroscopy were used for the material investigations. Qualitative non-invasive µXRF results allowed for categorisation of the glazes and ceramic bodies based on their overall composition. Quantitative analysis by SEM/EDX on a subset of the samples delivered detailed results on the bodies and glazes. Tiles, made from clay or stonepaste, were almost exclusively decorated with a mixed alkaline lead glaze. The PbO content of this type of glaze ranged from 8 wt% to 25 wt%. The clay bodies of some tiles corresponded to the material of the locally used kiln furniture. Moreover, glaze residues preserved on the kiln furniture proved to be from a mixed lead alkaline glaze with a PbO content of 15 wt% to 25 wt%, a composition that is comparable to the tiles’ glazes. For more insights into the local or regional production of the tiles, supplementary in-depth studies including petrographic analysis would be needed to confirm and further specify the results

A comparative compositional study of Egyptian glass from Amarna with regard to cobalt sources and other colourants

A selection of Late Bronze Age glass objects from the site of Amarna (Egypt) was analysed for their overall chemical composition, colourants and transition metals associated with the sources of cobalt ore. The objects were analysed by means of Particle Induced X-Ray and Gamma-ray Emission and Rutherford Backscattering Spectrometry at the IBC, HZDR, Dresden and the New AGLAE facility, C2RMF, Paris. The data was subsequently compared with further measurements obtained by portable X-Ray Fluorescence (and by Laser-Ablation Inductively-Coupled-Plasma Mass-Spectrometry) in order to sound the potential of these non-destructive methods to obtain new insights into the production process of glass from Amarna and its provenancing

Towards truly simultaneous PIXE and RBS analysis of layered objects in cultural heritage

For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Although the complementarity of both techniques has long been acknowledged, its full potential has not been yet developed due to the lack of general purpose software tools for analysing the data from both techniques in a coherent way. In this work we provide an example of how the recent addition of PIXE to the set of techniques supported by the DataFurnace code can significantly change this situation. We present a case in which a non homogeneous sample (an oxidized metal from a photographic plate -heliography- made by Niepce in 1827) is analysed using RBS and PIXE in a straightforward and powerful way that can only be performed with a code that treats both techniques simultaneously as a part of one single and coherent analysis. The optimization capabilities of DataFurnace, allowed us to obtain the composition profiles for these samples in a very simple way.Comment: 9 pages, 3 figure

Micro-SR-XRF and micro-PIXE studies for archaeological gold identification – The case of Carpathian (Transylvanian) gold and of Dacian bracelets

Abstract Trace-elements are more significant for provenancing archaeological metallic artifacts than the main components. For gold, the most promising elements are platinum group elements (PGE), Sn, Te, Sb, Hg and Pb. Several small fragments of natural Transylvanian gold – placer and primary – were studied by using micro-PIXE technique at the Legnaro National Laboratory AN2000 microbeam facility, Italy and at the AGLAE accelerator, C2RMF, Paris, France and by using micro synchrotron radiation X-ray fluorescence (micro-SR-XRF) at BESSY synchrotron, Berlin, Germany. The goal of the study was to identify the trace-elements, especially Sn, Sb and Te. A spectacular application to five Dacian gold bracelets authentication is presented (Sn and Sb traces)

Product of the art market? The representation of silver corncobs at the Ethnologisches Museum in Berlin

In the 1960s two similar silver corncobs attributed to the Chimú-Inca period were sold by New York based art dealers to the Museum für Völkerkunde in Berlin, now the Ethnologisches Museum, and to the Denver Art Museum. The composition of the Berlin piece shows the use of different alloys, suggesting the reuse of different pre-Columbian objects. Only the hard-solders used to join the different parts of the corncobs contain an amount of zinc that might indicate a modern intervention. The hypothesis of this article is that economic stability in the 1960s combined with the desire to restore Second World War losses in museums collections particularly in Germany paved the way for doubtable purchases including forgeries.En los años 1960 dos mazorcas de maíz similares, hechas en plata, atribuidas al período chimú-inca han sido vendidas por dos comerciantes de arte de Nueva York al Museum für Völkerkunde, hoy Ethnologisches Museum, de Berlín, y al Denver Art Museum. La composición de las dos piezas muestra el uso de diferentes aleaciones, lo que sugiere la reutilización de diferentes objetos precolombinos. Solo las soldaduras utilizadas para unir las diferentes partes de las mazorcas contienen una cantidad de zinc que podría indicar una intervención moderna. La hipótesis de este artículo es que la estabilidad económica en la década de 1960 combinada con el deseo de restablecer las pérdidas de la Segunda Guerra Mundial en colecciones de museos, especialmente en Alemania, facilitó el camino para compras dudosas incluyendo falsificaciones.Pendant les années 1960, deux représentations d’épis de maïs en argent, semblables, considérées comme chimú-inca, ont étés vendues à Berlin au Museum für Völkerkunde, aujourd’hui Ethnologisches Museum, et au Denver Art Museum, par deux marchands d’art new yorkais. La composition des deux pièces montre l’utilisation de différents alliages, ce qui suggère la réutilisation de plusieurs objets précolombiens. Seul, l’alliage utilisé pour joindre les différentes parties de l’épi de maïs par brasure contient une quantité de zinc qui fait penser à une intervention moderne. L’hypothèse de cet article est que la stabilité économique des années 1960 et la volonté de rétablir les pertes causées par la Seconde Guerre Mondiale dans les collections des musées, particulièrement en Allemagne, ont contribué à l’achat d’objets d’art d’authenticité douteuse et même de faux

Dacian bracelets and Transylvanian gold: ancient history and modern analyses

The recovery of the Dacian gold bracelets was the most thrilling archaeological event of the last years in Romania. The artefacts are exhibited in the Historical Treasure section of the National History museum of Romania, Bucharest, being recovered from the international antique markets through a concerted effort of the Romanian, French, and German authorities. This paper reviews the X-Ray Fluorescence (XRF) analyses carried out on these exquisite artefacts. These measurements followed the visual examination of qualified experts, which concluded that the gold spiralled bracelets showed strong stylistic similarities with the Dacian silver bracelets discovered until that date in archaeological contexts. Since the most likely source – for geographical and historical reasons – for the metal used to manufacture these artefacts was the Transylvanian Apuseni mountains, additional measurements on several fragments of natural Transylvanian gold, both from placers and primary deposits, were performed using Synchrotron Radiation X-ray Fluorescence (SR-XRF) at the BESSY synchrotron, Berlin, and micro Particle Induced X-ray Emission (micro-PIXE) at the AGLAE accelerator, Paris, and at the AN2000 accelerator of LNL, Padova. The conclusion of this study was that the recovered spirals are genuine Dacian artefacts, made by cold hammering, chiselling and punching Transylvanian unrefined gold – gold panned from riverbeds mixed with primary gold, most likely extracted from surface veins.La saisie des bracelets en or de Dacie a été un des événements archéologiques les plus remarquables de ces dernières années en Roumanie. Les objets sont exposés dans le Trésor Historique du musée National d’Histoire de Roumanie, Bucarest, et ont été récupérés du marché international d’antiquités grâce aux efforts concertés des autorités Roumaines, Françaises et Allemandes. Cet article fait le bilan de l’analyse de ces objets exquis, réalisée par fluorescence à rayons X (FX). Ces mesures suivent l’examen visuel par des experts qualifiés qui ont conclu que les bracelets en or à spirales montrent des similitudes stylistiques fortes avec les bracelets en argent de Dacie découverts en contexte archéologique. Comme pour des raisons historiques et géographiques la source la plus probable du métal utilisé pour la fabrication de ces objets se trouve dans les Carpates transylvaniens, des mesures complémentaires ont été réalisées sur différents fragments d’or natif de Transylvanie, provenant tant de placers comme de gisements primaires, par fluorescence de rayons X avec radiation de synchrotron (SR-XRF) au synchrotron BESSY, à Berlin, et par émission de rayons X induite par particules chargées (micro-PIXE) à l’accélérateur AGLAE, à Paris, et à l’accélérateur AN2000 du LNL à Padoue. L’étude à permis de conclure que les bracelets en spirale récupérés sont des objets Daciens authentiques, produits par martelage à froid, ciselure et poinçonnage d’or de Transylvanie non affiné – de l’or de rivière obtenu par batée et mélangé avec de l’or primaire, certainement extrait de filons de surface

Authenticity investigation on Limoges painted enamels by means of micro x-ray fluorescence analysis

Aufgabe der Kunstgeschichte ist die Suche nach Kriterien, die es erlauben, authentische Kunstwerke von Kopien oder Werken im Stil historischer Stücke zu unterscheiden. Die Nachfrage nach Stücken einer Kunstgattung übersteigt häufig das Angebot, was die Produktion von Nacharbeiten oder Fälschungen lukrativ macht. Dieses trifft auch auf die Werke des Kunsthandwerkes der Renaissance zu, die sich im 19. Jh. großer Beliebtheit erfreuten. Dazu zählen auch die Limousiner Maleremails, die hauptsächlich in der Zeit vom späten 15. Jh. bis teilweise noch in das frühe 18. Jh. in der Stadt Limoges in Frankreich produziert wurden. Besonderes Merkmal der Limousiner Maleremails ist, dass niedrigschmelzende Glasflüsse direkt miteinander verlaufend auf Kupfer aufgetragen wurden, so dass die Farben nicht durch Metallstege voneinander getrennt sind. Mit analytischen Methoden sollten zeittypische Veränderungen der Emailflüsse festgestellt werden, um strittige Objekte durch Analysen in einen zeitlichen Kontext einordnen zu können. Zu diesem Zweck wurde ein Gerät entwickelt, mit dem sich Mikro-Röntgenfluoreszenzanalysen direkt in den Sammlungen durchführen lassen. Das Spektrometer verwendet eine Polykapillar-Röntgenoptik, um einen kleinen Messfleck(Durchmesser ¡Ü 100 µm) zu erzeugen und kommt durch die Verwendung eines Silicium-Driftkammerdetektors ohne die Kühlung mit flüssigem Stickstoff aus. Weiterhin zeichnet es sich durch Transportfähigkeit, eine flexible Probenpositionierung ohne Probenkammer und eine Vorrichtung zum Messen in einem konstanten Heliumgasstrom aus. Durch Messen in Helium ist eine Detektion aller Elemente von Natrium bis Uran möglich. Eine standardgebundene Quantifizierungsmethode für die Analytik an Glas und Email wurde erarbeitet. Die Messungen an den Objekten wurden bei einer Messzeit von 100 s durchgeführt. Die Richtigkeit, mit der die Hauptbestandteile erfasst werden können, liegt in der Regel bei 10 % rel. Nachweisgrenzen von 30 ppm wurden für die Übergangselemente erreicht. In einer Datenbank wurden die Ergebnisse der Elemente von Aluminium bis Zink (außer Argon und Schwefel), sowie Arsen, Rubidium, Strontium, Silber, Zinn, Antimon, Blei, Bismut und Uran zusammen getragen und bezüglich zeittypischer Veränderungen ausgewertet. Als ergänzende Methoden wurden die Elektronenstrahl-Mikroanalyse und die Laserinduzierte Plasmaspektrometrie verwendet. An 165 Kunstwerken, die aus zehn internationalen Sammlungen stammen, wurden Untersuchungen durchgeführt. Anhand der Maleremails aus der Zeit zwischen 1500 und 1760, sowie dem späten 19. Jh. konnte festgestellt werden, dass sich die Objekte des späten 19. Jh. durch ihre Zusammensetzung von denen der früheren Herstellungsperioden unterscheiden. Ein Charakteristikum ist dabei die Verwendung von Chrom, Uran, Cadmium, Selen und Iridium, die auf eine Produktion im oder nach dem 19. Jh. schließen lassen. Generell sind ab 1800 auch die Gehalte der Begleitelemente und Verunreinigungen, die durch das Flussmittel oder das Silicatmaterial in das Email gelangten, geringer. Bei den Nacharbeiten finden sich als wesentliches Merkmal nur Emails mit hohen Bleigehalten über 20 Gew.%, während die originalen Werke ganz oder nahezu bleifreie Emailflüsse aufweisen. Bei den getrübten weißen Emailflüssen wird ab der Mitte des 18. Jh. das ursprünglich verwendete Zinn-Blei-Weiß durch Bleiarsenat-Weiß ergänzt. Schwieriger, aber auch möglich, sind weitere Eingrenzungen des Herstellungszeitraumes für die originalen Maleremails über Elementverhältnisse in bestimmten Emailflüssen, wie z.B. den Gehalten von Arsen und Blei in cobaltgefärbten Flüssen. Gedruckte Version im Mensch & Buch Verlag Berlin [http://www.menschundbuch.de] erschienen.Finding criteria to distinguish between authentic art objects and later objects made in the style of or simply as copies of earlier works presents often a major challenge for art historians. The demand for pieces in a particular style of art frequently outstrips the supply which leads to the remunerative manufacturing of imitations and forgeries. This is especially true for applied arts from the Renaissance which saw a remarkable revival in the nineteenth century. Such objects include Limoges painted enamels, which were mainly produced from the late 15th century to the early 18th century in the French town of Limoges. The Application of low-temperature melting glass fluxes in various colour on a copper base without separation by metal strips is characteristic for Limoges painted enamels. The aim of this study was to determine changes in the compositions of the enamel fluxes over the centuries by material analysis. The results obtained help to attribute doubtful objects to a certain production period. For this purpose a portable spectrometer was developed which allows micro x-ray fluorescence analysis to be carried out on the collections. This spectrometer utilizes a polycapillary x-ray "lens" to focus the x-ray spot down to ¡Ü 100 µm and does not require cooling with liquid nitrogen by application of a silicium drift chamber detector. Furthermore, the spectrometer features a high flexibility in sample positioning without a sample chamber, a device for measuring in a constant flow of helium gas, and is easy to transport. By measuring in helium atmosphere is was possible to detected all elements from sodium to uranium. An empirical quantification method based on standards for analysing glass and enamel was established. Measurement time for the analysis of art objects was 100 s. The accuracy of the determination of the main components was 10 % relatively. Detection limits of approx. 30 ppm were reached for the first row transition metals. All quantitative results of the elements from aluminium to zinc (excluding argon and sulphur) as well as arsenic, rubidium, strontium, antimony, lead, bismuth and uranium were gathered in a database. Additional methods such as electron probe microanalysis and laser induced breakdown spectrometry were also utilized. All results were evaluated for chronological changes. About 165 objects from ten international collections were analysed. The analysis of painted enamels from 1500 to 1760 and the late 19th century showed, that the objects from the 19th century differ in composition from those produced in the earlier production period. One difference is the use of chromium, uranium, cadmium, selenium and iridium, which is characteristic for production dates in or after the 19th century. The content of trace elements, which come into the glass matrix by the use of poorly purified fluxing agents or silicate material, tends to be lower in objects produced from 1800 onwards. For 19th century objects it is distinctive that only enamel fluxes with high lead contents (over 20 wt.%) were applied. Genuine objects usually exhibited fluxes with a low lead content. After the middle of the 18th century, the traditionally used opaque white, a enamel containing high percentages of tin and lead, is a time substituted by a lead arsenate white. A more delicate issue - but still possible - is the definition of the production dates of genuine painted enamels between the 16th and 18th century. For this purpose the ratios of elements in specific enamel fluxes are helpful, e.g. the content of arsenic and bismuth in cobalt including fluxes. Printed version available from MENSCH & BUCH VERLAG, Berlin [http://www.menschundbuch.de]

Between Fakes, Forgeries, and Illicit Artifacts—Authenticity Studies in a Heritage Science Laboratory

Since its inauguration in 1888, the Rathgen Research Laboratory of the National Museums in Berlin has been challenged by authenticity questions on cultural heritage objects. In the setting of an ever-growing market, often intertwined with the increasing global impact of illicit traffic, scientific investigations can contribute equally to art-historical, or archaeological expertise when solving questions of authenticity, and should therefore always be included when significant values are at stake. Looted or stolen artifacts, copies, fakes, and forgeries have been an intrinsic element of the market since ever, and only selectively addressed in a trans-disciplinary, more holistic way. This paper makes the case for a reliable, state-of-the-art analysis and illustrates the potential benefits of such a scientific approach to authenticity questions in selected examples: 1. the case of German art forger, Wolfgang Beltracchi; 2. brass objects of alleged Benin and Ife provenance