Papers by Katharina Uhlir
Microchemical Journal, 2016
Abstract 40 Sasanian silver coins of the emperor Khusro II (591–628) belonging to the Coin Collec... more Abstract 40 Sasanian silver coins of the emperor Khusro II (591–628) belonging to the Coin Collection of the Kunsthistorisches Museum Vienna (KHM) as well as 188 coins of the same emperor acquired at the free coin market were analyzed using micro-X-ray fluorescence analysis (μ-XRF) in the course of the research project “Sylloge Nummorum Sasanidarum”. These studies revealed the presence of mercury in the XRF spectra of a bigger part of the coins. First investigations with complementary techniques showed that the mercury is present as a surface layer. Therefore, further detailed studies were performed on polished sections using the Particle Induced X-ray Emission technique with a proton microprobe (μ-PIXE) that offers quantitative and spatially resolved elemental information with micron resolution, scanning micro-X-ray fluorescence (μ-XRF) analyses for a better understanding of the elemental distribution on the surface and polished sections of the coins and finally confocal micro-XRF (3D μ-XRF or CMXRF) analyses for revealing information on the surface layering and elemental in-depth distribution. The synergistic application of these methods offered detailed and improved information on the structure of the mercury-layer on the surface of the silver coins supporting assumptions dating back to 1976/78 indicating medical treatments using Hg as basis for this phenomenon.
Es wurden Glasproben von antiken Glasgefäßen mittels energiedispersiver Mikro-Röntgenfluoreszenza... more Es wurden Glasproben von antiken Glasgefäßen mittels energiedispersiver Mikro-Röntgenfluoreszenzanalyse (µ-RFA) und energiedispersiver Röntgenmikroanalyse im Rasterelektronenmikroskop (REM/EDS) untersucht. Die Proben stammen von Fundstücken aus Ephesos/Türkei. Hierbei handelt es sich einerseits um Gläser, welche aus einem luxuriös ausgestatteten Wohn- bzw. Amtsbereich (Hanghaus 1) stammen, andererseits um Glasfunde aus der Agora von Ephesos, wo Reste von antiken Glasöfen eine Nutzung als Glaswerkstätte nahelegen. Es sollten drei Fragestellungen geklärt werden:a) Eine Klassifizierung und Charakterisierung der analysierten Glasproben bezüglich ihrer Zusammensetzung, b) ein Vergleich der Glasproben aus der Agora mit jenen aus Hanghaus 1, um die Möglichkeit der lokalen Produktion zu prüfen und c) die Feststellung der möglichen Provenienz aller Gläser.Für die quantitative Analyse wurde ein neu entwickeltes µ-RFA-Gerät verwendet, dessen Instrumentcharakteristika im Vorfeld genau untersuch...
Restaurator. International Journal for the Preservation of Library and Archival Material
The investigation and conservation of the Vienna Genesis, a Late Antique manuscript on purple par... more The investigation and conservation of the Vienna Genesis, a Late Antique manuscript on purple parchment, included the study of parchment production and purple dyeing in the sixth century. The process of parchment making and of purple dyeing was recreated and compared with the Vienna Genesis and other manuscripts from the sixth and eighth centuries. Parchment made from the hides of young lambs and dyed with orchil resembled the folios of the Vienna Genesis. The results of material analysis and the study of parchment technology influenced decisions for the conservation and storage of the manuscript. Fragile areas of ink and parchment were stabilised with strips of adhesive coated Japanese tissue paper. The single folios are stored in folders of Japanese paper and museum matboard within a sink mat.
The Vienna Genesis (Austrian National Library, Codex Theologicus graecus 31) is a fragmentary Gre... more The Vienna Genesis (Austrian National Library, Codex Theologicus graecus 31) is a fragmentary Greek manuscript of the Book of Genesis written on purple dyed parchment with silver ink. It is assumed that the book was created in the first half of the 6th century in the Near East. 24 folios with 48 miniatures have survived and have been stored at the Austrian National Library since 1664. The Vienna Genesis is famous for its rich cycle of biblical illuminations. The silver ink´s degradation, which has resulted in extensive damage to the parchment, was already observed in the 17th century. In a three-year research project the parchment, the silver inks, the pigments and dyes were investigated. The detailed material analysis formed the base for conservation and preservation of the manuscript. The book describes the different studies of the project and their results: •How was parchment made in Late Antiquity? •How was parchment dyed purple? •What is the purple dye of the Vienna Genesis? •Which pigments were used by the different painters? •What is the composition of the silver ink and what are the causes of the severe damage? •How can the Vienna Genesis be best conserved for the future?
Ägypten und Levante, 2018
The article reports on the results of the project of non-destructive X-ray fluorescence analysis ... more The article reports on the results of the project of non-destructive X-ray fluorescence analysis of 15 artefacts, deposited in the Egyptian and Near Eastern Collection of the Kunsthistorisches Museum Wien. Artefacts from the sites of Giza, Kubbaniya, Mostagedda, Tura and Toshka were chosen, predominantly from documented archaeological contexts. The periods represented are Early Dynastic, the Old Kingdom, the Middle Kingdom and the Nubian C-Group. The finds were excavated and published by H. Junker and G. Brunton, yet they were analysed for the first time only in the framework of this project. The analysis confirmed the use of copper with impurities in the Early Dynastic period and of arsenical copper in the Early Dynastic period, the Old Kingdom, the Middle Kingdom and the Nubian C-Group. Moreover, on a Dynasty-4 carinated bowl with spout (AS 7441) was discovered previously unknown inscription, most probably of the Vizier Seshathetep Heti.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2017
The Coronation Gospels or Krönungsevangeliar is a manuscript kept in Vienna at the Kunsthistorisc... more The Coronation Gospels or Krönungsevangeliar is a manuscript kept in Vienna at the Kunsthistorisches Museum Wien, datable to the end of VIII century A.D. and produced at Charlemagne court. It is an example of a purple codex, i.e. its parchment is coloured in purple. It has to be considered as one of the most important medieval codices, according to its use to take oath in the coronation ceremony of kings and emperors of the Holy Roman Empire up to 1792. In order to gather information of the manufacture of the manuscript and its present conservation state, a diagnostic investigation campaign has been carried out in situ with totally non-invasive techniques. X-ray Fluorescence Spectrometry (XRF), UV-visible diffuse reflectance spectrophotometry with optical fibres (FORS), spectrofluorimetry, optical microscopy and multispectral analysis have been applied in order to identify the colourants used in the decoration of the manuscript, with the main concern to the dye used to impart the purple hue to the parchment. The information collected was useful in order to address some of the questions raised by art historians concerning its history.
Science for Cultural Heritage, 2010
X-ray Spectrometry, 2010
A portable focused-beam X-ray fluorescence (XRF) spectrometer was designed and manufactured takin... more A portable focused-beam X-ray fluorescence (XRF) spectrometer was designed and manufactured taking into account a huge variation in material, size and shape of museum objects. The spectrometer is equipped with a vacuum chamber enclosed with a Kapton-window allowing the detection of chemical elements from Na upwards, which enables the characterization of glass and enamel objects. Two low-power X-ray tubes, one with a Mo-anode the other with a Cr-anode, operating from 4 to 50 kV and 0 to 2.5 mA with a maximum power of 50 W and a point focus of about 180 µm can be used as excitation source alternatively. A polycapillary lens with a spot size of 150 µm is used for focusing the primary beam to access small details of the different objects, e.g. fine brush strokes in paintings. The vacuum chamber can be evacuated to about 1 mbar. A miniature camera is installed inside the chamber for inspecting the analyzed area through the Kapton-window. Two laser pointers mounted inside the chamber coincide with the focal point of the polycapillary at the investigated spot. The excitation and X-ray fluorescence radiation paths in air are about 1 mm each, minimizing the absorption losses. The spectrometer was designed to maximize the accessibility to all parts of the investigated objects through the use of translation stages and an innovative design of the detection head, especially the vacuum chamber. This article shows the capability of the spectrometer to reach measuring positions in concave parts of objects and presents the determined detection limits of elements. Copyright
Journal of Analytical Atomic Spectrometry
Laser-Induced Breakdown Spectroscopy (LIBS) was used for the depth-profile analysis of one Sasani... more Laser-Induced Breakdown Spectroscopy (LIBS) was used for the depth-profile analysis of one Sasanian coin of the emperor Khusro II (591-628) from the Coin Collection of the Kunsthistorisches Museum Vienna. The...
X-Ray Spectrometry
Rembrandt's painting Old Woman Praying, 1629/30, is the most valuable and exceptional work of art... more Rembrandt's painting Old Woman Praying, 1629/30, is the most valuable and exceptional work of art of the Residenzgalerie Salzburg (RGS). It is painted on a gilded copper plate with dimensions of only approximately 15 × 12 cm. The painting probably belongs to a series of three small-scale tronies, all executed on gilded copper plates. This particular picture preparation, which represents a special feature in Rembrandt's work, is quite unusual in the history of art. Previous investigations on the comparable paintings The Laughing Man, 1629/30, in the Mauritshuis, The Hague and the Self Portrait, 1630, in the National Museum, Stockholm showed that the gilding of the copper plate was applied over a lead white ground. To characterize the painting in the RGS, X-ray fluorescence (XRF) mapping was performed in a collaboration between the Research Office Residenzgalerie, Land Salzburg, the XGLab S.R.L, Milan, and the Conservation Science Department of the Kunsthistorische Museum Vienna (KHM). The results indicate a different structure for this painting than that used for The Laughing Man and the Self Portrait. The gilding was applied directly onto the copper plate, but with three areas with the gilding missing. It seems likely that in these sections, the gold was purposely removed to provide a different darker effect. XRF mapping yielded valuable insights into the structure of the painting and its technique as well as the principal pigments used for its composition.
Scientific investigation and study of the 16th century glass jewellery collection of Archduke Fer... more Scientific investigation and study of the 16th century glass jewellery collection of Archduke Ferdinand II at the Kunsthistorisches Museum Vienna The “Kunstkammer” (Collection of Sculpture and Decorative Arts) of the Kunsthistorisches Museum in Vienna holds a unique 16th century glass jewellery collection composed of 391 pieces. Originally, these pieces were part of Archduke Ferdinand’s II “Kunst- und Wunderkammer”, located at Ambras Castle near Innsbruck. As an encyclopedic collection it attracted scholars, sovereigns and travelers from all over Europe. Among those precious works of art were fragile glass items such as figurines, earrings, buttons, floral bouquets and chains, mounted on silk cushions. The glass jewellery collection’s history seems to be closely linked to Archduke Ferdinand II. In 1570 he had a glasshouse installed, which was to produce glass exclusively for his personal demand. To meet his high artistic standards, he engaged Venetian glassworkers, who worked in Inn...
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Papers by Katharina Uhlir