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Gold mosaics, made from gold and glass, are one of the best expressions of Late Antique Byzantine and Early Islamic art. The gold alloys, whose composition seems to indicate that gold coins were re-used to fabricate the tesserae, can be used to provide information on the mosaics chronology. Monetary Byzantine gold is in fact characterized by the presence of Pt, which contents in the gold alloy change over time, but Pt must be measured in 0.2-0.4 µm thickness gold leaves that were beaten to be sandwiched between two glass layers.
To analyze this samples the D²XRF set-up at the BAMline at the BESSY synchrotron in Berlin was used. The combination of a crystal for wavelength dispersion and an energy resolving single photon counting pnCCD allows the realization of this very simple wavelength dispersive detection system. With this system an MDL of 1 μg/g for the determination of Pt in Au under optimal conditions can be reached.
Gold leaf tesserae from nine archaeological sites, covering the period that goes from the 5th c. to the 8th c., were analyzed. The presence of Pt in the majority of the samples confirmed the re-use of coins. The Pt contents separate the samples in three groups, one of which having the same chemical characteristics as the Byzantine gold could be compared to dated coins for chronology. The higher Pt contents for one of other groups suggest
The international Qumran project coordinated at the BAM, Berlin, resulted in an integrated methodology for determining the original and acquired properties of the skin-based writing surfaces of the Dead Sea Scrolls. This methodology offers a powerful tool for addressing such questions as the provenance, sorting and comparison of manuscripts. In addition, we have developed specific protocols for on-site studies, which were successfully applied to the fragments from the Schøyen collection in Norway. Our studies show that the Dead Sea Scrolls writing surfaces can be divided roughly into three groups: leather, parchments of a light tint, and those of various shades of brown. The latter ones are invariably tanned, whereas the middle group is characterized by the presence of various inorganic salts. Some of the pale parchments, among them the Temple Scroll (11Q19), are remarkably similar to medieval European parchment. Therefore we have formulated the working theory that in the Judaea of the Hellenistic period two different parchment-making traditions existed side by side: an ‘eastern’ one (represented by the tanned parchments of Qumran, closely resembling Aramaic documents from the fifth century BC, and a ‘western’ one (represented by the untanned/lightly tanned ones similar to early Christian Greek parchments).
This division has found support during our first pilot study of the Geniza fragments, in which Babylonian and Palestinian traditions seem to follow the “eastern” and “western” technologies, respectively.
The evolution and socio-geographic distribution of writing inks in late Antiquity and the early Middle Ages build the second focus of the BAM group. We use X-ray fluorescence analysis (XRF) to determine the chemical composition of the inks and NIR-reflectography for their typology. Here the early appearance of the metal containing inks clearly belongs to the western tradition as opposed to the continuous use of soot inks in the East.
The lecture will discuss the sensitive issue of authentication of the objects of cultural heritage of immense cultural and monetary value if certified to be genuine. It will be made clear that material analysis alone, especially its non-destructive variety conducted by specialists in a single technique, can not prove that the object is genuine. The best material analysis can do, after all appropriate tests have been conducted, is to announce that nothing has been found that contradicts the assumption of genuineness. Moreover, the results of the natural analysis can never be used as the only justification of the authentication in the cases of composite objects such as manuscripts or epigraphs. A certification always requires the expertise of the specialist in the field (be it a historian, paleographer, epigrapher, etc.), whose judgment can be at the most supported by appropriate material analysis.
The most effective approach for testing suspicious artifacts has been established by the forensic science. Here, not the authentication, but the determination of the forgery stands in the focus of the work. Investigation protocols developed within 150 years and constantly improved include a clear statement of the analysis purpose and the definition of plausibility criteria for the possible outcome. The younger sister of the forensics, archaeometry has to overcome additional obstacles such as the heterogeneity of historic material coupled with the scarcity of suitable reference material. Over the last two decades the popularity of archaeometric studies has increased enormously, with the industry-driven development of so-called non-destructive technologies (NDT) that do not require sampling. Further technological developments led to the appearance of NDT methods with extremely small interaction windows (µm range). Each of these methods has limitations that have to be carefully considered when planning the tests of a heterogeneous and often partially degraded historical material. This approach is inherently multi-instrumental, therefore archaeometric and forensic departments unite a number of specialists who work together defining the tasks and the methods involved for their successful completion.
The experimental knowledge about the inks of antiquity and late antiquity rarely goes beyond their visual description. In rare cases, inks typology has been determined by means of microscopy and reflectography, i.e. using their physical and optical properties, respectively. Soot, plant, and iron gall inks form different typological classes of historical black writing materials. Soot ink is a fine dispersion of carbon pigments in a water-soluble binding agent; plant-based ink consists of tannin solution; iron gall-ink presents a boundary case between soot and plant ink— a water soluble preliminary stage (similar to inks from the second group) oxidizes and evolves into a black, insoluble material (similar to the carbon pigments of the first group) when the writing is exposed to air. Each ink class has distinct properties that would readily permit their easy differentiation, if only these historical inks always belonged to just one of the classes above. In reality, inks may contain additives that obscure a clear picture.
All the black inks of the DSS have been hitherto identified as soot inks. Yet some manuscripts, with 1QapGen ar among them, display ink corrosion that is incompatible with the pure soot ink. This type of corrosion commonly observed in medieval manuscripts written with iron gall inks, results from the catalytic action of metallic component in the ink. Early analysis of this ink conducted by Nir El and Broshi in 1996 found copper in the corrosive inks and attributed its presence to the use of bronze inkwells. Re-investigation of the 1QapGen ar ink suggests, however, that the ink composition, soot + copper, agrees well with the ink recipe recorded in the 1st century CE by Dioscorides. Similar inks have been already attested on contemporary Egyptian papyri. The first part of the paper is dedicated to the new results on the inks and corrosion pattern of the 1QapGen ar.
In the second part of the presentation I will focus on the luxury scrolls, a distinct codicological type introduced by E. Tov. Our studies show that the preparation of the writing materials cannot supplement the list of codicological criteria offered by Tov. Therefore, one can divorce the writing material production from its inscription in contrast with the medieval scriptoria practices that included parchment production and copying of the manuscripts.
Material study of inks
(2016)
Our experimental knowledge about the inks of antiquity and late antiquity rarely goes beyond their visual description. In rare cases, inks typology has been determined by means of microscopy and reflectography, i.e. using their physical and optical properties, respectively. Soot, plant, and iron gall inks form different typological classes of historical black writing materials. Soot ink is a fine dispersion of carbon pigments in a water-soluble binding agent; plant-based ink consists of tannin solution; iron gall-ink presents a boundary case between soot and plant ink— a water soluble preliminary stage (similar to inks from the second group) oxidizes and evolves into a black, insoluble material (similar to the carbon pigments of the first group) when the writing is exposed to air. Each ink class has distinct properties that would readily permit their easy differentiation, if only these historical inks always belonged to just one of the classes above. In reality, inks may contain additives that obscure a clear picture.
Even crude observations suggest that the inks of antiquity differed greatly in their composition. We believe, that reconstructing the ink recipes with the help of advanced non-destructive analytical techniques could serve as a powerful accessory in the studies of ancient papyri.
The proposed paper will present a short survey of the methods of material analysis and the challenges offered by ancient inks. (Two) examples of ink studies from the collections of the Israel Museum in Jerusalem and Egyptian Museum in Berlin will conclude the paper.
Le monde de la Génizah du Caire et plus particulièrement la collection de Cambridge (CUL) a recu l’attention des chercheurs depuis le XIXe siècle mais peu de recherches ont été faites à ce jour sur l’aspect matériel des manuscrits. Pourtant l’archéométrie est un outil précieux pour mieux comprendre les sociétés qui ont créés ces documents.
Analysis of writing materials in Genizah fragments written during the first half of the XIth century
(2017)
My doctoral dissertation in progress focuses on ink composition on some fragments found in the Cairo Genizah and written by the leaders of the Jewish communities in Fustat during the first half of the XIth century. This is a project at the intersection of historical (Hebrew paleography) and scientific (physics, chemistry and materials science) disciplines. Indeed, I’m analyzing the corpus I constituted (written by Ephraim ben Shemarya and Yephet ben David from the Palestinian congregation and Elhanan ben Shemarya, Abraham ben Sahlan and Sahlan ben Abraham from the Babylonian community). The interests of such a study are numerous: provide insights on trade, local technologies, and social structures. If sufficient data is collected, the tabulated results have the potential for use as an indirect geochronological marker, in particular in the case of iron-gall ink. The composition of the vitriol used for the iron-gall ink preparation depends on the place of extraction. While attributing the vitriol used to a specific source of extraction is seldom possible, a number of origins can be excluded thanks to such analysis. Though ink composition alone cannot be used as a direct geochronological marker, superposition of chemical, palaeographical, codicological, and textual data would help to date and localize and serve as an additional argument for a typology and dating of other Hebrew scripts.
L'archéométrie est une discipline riche qui peut nous apporter beaucoup d'informations sur l'étude des manuscrits et qui, conjuguée à la paléographie et la codicologie, peut s'apporter un outil précieux pour mieux appréhender les sociétés qui ont produits ces manuscrits.
Nous verrons ici quelques exemples de techniques scientifiques non destructives, principalement appliqués à la Génizah du Caire, appliquées à l'étude des manuscrits.