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We report results of the patina study of underwater archeological finding of medieval copper objects performed by means of the Raman and complementary spectroscopic techniques. The objects were found submerged in the sea as cargo part of the ship which sunk in the Gulf of Gdańsk in 1408. The excavated collection consists of 230 oval ingots of the size and mass up to about 60 cm and 18 kg (total of 2 tons), respectively. In the Raman spectra of the strongly porous ingot encrustation, the bands corresponding to the main patina representatives such as cuprite (Cu2O), atacamite (Cu2(OH)3Cl) and chalcopyrite (CuFeS2), and also chalcocite (Cu2S) and covellite (CuS) are observed and confirmed by the elemental analysis. Raman bands located at 1473 cm−1 and also at 909 and 511 cm−1 are ascribed to the organic Ca‐oxalate (whewellite, CaC2O4 · H2O) in agreement with the infrared spectra and surface morphology observed in microscope images. The presence of S, C, Ca, and Fe revealed by the energy dispersive X‐ray spectroscopy indicate on patina components resulting from reactions in the microbial environment in seawater and on contributions coming from iron bars, tar, and burnt remains which were also found in the excavated cargo. The results are consistent with literature data on copper ingots from Hungary traded along the south–north route in medieval Europe. Copyright © 2016 John Wiley & Sons, Ltd.

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In the 19th century, the evolution of white, yellow and other pigments was forced by numerous chemical discoveries. Dates of their inventions and patents, despite being well established in the literature, are not consistent with time of their implementation by painters. The survey of more than 300 hundred Polish artists' paintings from the period 1838 -1938 confirmed this observation. The reported research allowed building chronological database of the first use, periods of intensive exploitation and of the decline of use or absence of specific pigments in the Polish artists' studio practice. Portable XRF examination, Raman spectroscopy and SEM-EDX analysis enabled establishing dates of first applications of zinc white, chrome yellow, cadmium yellow, strontium yellow, zinc yellow, emerald green and viridian on paintings. Moreover, the research showed modifications of Naples yellow by zinc-or tin-based admixtures in the second half of the 19th century as well as evolution of additives to basic lead white such as earth pigments, chalk, barites, zinc white or lithopone. The accuracy of dating and authentication of the artworks analysed was strengthened by examination of composition of their grounds. In some cases individual habits of artists of using special kinds of primings or characteristic pigments were revealed giving a support for authentication studies. The data gathered in this research proved to be a reliable basis for attribution and dating of paintings of uncertain origin.

The surface layers resulting from prolonged exposure to the indoor environment and the bulk material of metal artifacts from the collection of National Museum in Gdansk are studied by means of spectroscopic techniques. The composition of the surface layers of the forged iron box lid covered with polychrome (XVI c.), and of the bronze female nude sculpture (antiquity) is obtained from the XRF and µ-Raman spectra. The elemental composition is confirmed by the LIP (Laser Induced Plasma) spectroscopic measurements. The quasi-nondestructive LIP technique applied for stratigraphic sampling performed with an accuracy of ca 2 µm across the multilayer surface coverage reveals such elements as C, Ba and Na in the uppermost layer. From coincidence of the XRF, Raman and LIP data the presence of surface contaminant CaCO3, the corrosion product FeO(OH) and patina Cu2 (OH)3Cl are concluded. It is shown that the complementary spectroscopic analysis allows for the in-depth study of the environmental impact on historical objects and delivers indications for the appropriate strategy of the planned conservation activities. Moreover, from the data collected from the technologies applied in the past, origin, provenance and routing of the artifacts can be concluded.

Abstract-Advantages of the complementary use of spectroscopic techniques are exemplified by the analysis of a historical bronze mortar from XV c. performed as part of the running collection conservation project by the National Museum in Gdansk. The bulk material and surface layers are analyzed by means of the XRF and µ-Raman techniques. Quasi-nondestructive LIP (Laser Induced Plasma) spectroscopy delivers additional data on the elemental composition and is applied also for stratigraphic sampling across the surface layers.A detailed understanding of the environmental impact on historical metal artefacts is of considerable importance for their preservation. In most cases, the poor state of historical metal objects and collections being a significant part of our cultural heritage results from prolonged exposure to adverse environmental conditions This paper presents the results of analysis of the material and patina of the historic bronze mortar (Fig. 1) by means ofRecently, systematic research on historic collections and case studies show that the combination of spectroscopic and optical techniques for elemental, compositional, and structural analysis enhance greatly the reliability of results [2][3]. Moreover, non-destructively operating instruments allow us to keep the impact on valuable and precious objects extremely low.complementary spectroscopic methods, which ensure reliable characterization of the object. The bronze mortar (XV c.) produced by casting has a bell shape and a rectangular handle * E-mail: izmuda@imp.gda.pl -see Fig. 1.Typically, the gothic mortars were decorated with reliefs based on architectural motives. The object under investigation originates most probably from Gdańsk and represents a modest version of the dish characterized by a smooth, not ornamented coat. Dishes of this type were popular in Northern Europe in the fifteenth century. The mantle just above the foot is slightly bellied with a little horizontal crack visible on the surface. The entire surface is covered with a homogeneous layer of brown patina with the exception of the foot edge. The light reflection on the surface may originate from the protection layer applied during previous conservation. Small t An elemental analysis of the object was carried out races of a greenish-coloured patina are present on the foot reverse and the handle, too.non-invasively by means of an X-ray fluorescence spectrometer (XRF) completed at IF-FM PASci. The spectrometer X-ray tube IS601.5 (Italstructures) used for excitation has produced an excitation beam collimated to a spot of 4 mm in diameter. The tube was operated at 50kV and 1mA, and ensured detection of elements in the range from K (19) to U (92). During measurements an accumulation time of 120s for recording of each spectrum was applied.The XRF results were supplemented by the LIBS data in order to increase the level of confidence of the detected elements. The LIB spectra were recorded under pulsed excitation with an Nd: YAG laser (Quantel) operated at 1064nm and energy density of 2J/cm -2 ...

Results of spectroscopic investigation of the historical copper and copper alloy objects covered by patina and surface contamination are reported and discussed in this work. For analysis of the surface layers (bulk material, primer/grounding, patina and atmospheric contamination) the Laser Induced Breakdown (LIBS), Raman and X-ray fluorescence (XRF) spectroscopic techniques are used. Useful data on chemical structure and composition are obtained from stratigraphic analysis performed by a stepwise layer penetration with successive laser pulses. The LIBS, XRF and Raman spectra confirm the presence of patina and contamination layers of the compositions influenced by the atmospheric environment. The elemental composition reveals in the case of the original copper substrate the presence of Cu with traces of Ag and Sb, and of impurities Fe and Pb, while objects made of copper alloys (brass) show different Zn/Cu ratios greater than 20% in all cases and admixtures of Sn and Pb. Consistent results are obtained from the elemental and Raman data indicating presence of the antlerite (Cu 3 (OH) 4 SO 4 ), carbon and microcrystalline calcite which are ascribed to patina, surface contamination (atmospheric soot) and primer layers, respectively. INTRODUCTIONFor historical metal objects the elemental and chemical compositions are of key importance in studies on the production technologies and can provide useful data on the origin (authentication), provenance and routing. The recent case studies and reviews confirm that among analytical tools the laser-induced breakdown spectroscopy (LIBS), and also the Raman and X-ray fluorescence (XRF) techniques belong to the most reliable ones and are broadly applied in analysis and conservation studies 1-6 . These techniques are characterized by a high sensitivity (tens of ppm), non-destructive interaction with the object (micro-destructive in case of LIBS), immediate results, and possibility of the in-situ analysis. In course of the LIBS micro-sampling the spectra of laser-ablated and vaporized material are acquired. The thickness of the ablated layer lies obviously in the range of 1-3 m and the depth resolution can be controlled to some degree by the laser pulse parameters 7,8 . The LIBS performed repeatedly at the same location on the surface delivers data on elemental composition of the material in dependence on the penetration depth. In case of XRF the spectrum corresponds to the surface layer of a thickness depending on the penetration depth of the focused X-ray beam which varies from several up to tens of micrometers when going from metals to e.g. minerals. This may cause difficulties in the correct interpretation of the results, because the presence of elements detected in the uppermost surface layers including corrosion products, patina and contaminations is revealed in the spectrum.In this work the LIBS, XRF and also Raman spectroscopic techniques are used in frames of the running conservation project for investigation of the surface layers of historical objects made of copper and co...

Abstract-In this work, Raman spectroscopy and complementary