Mössbauer Spectroscopic and Chromaticity Analysis on the Colourative Mechanism of Ancient Goryeo Celadon from GangJin and Buan

In ancient Goryeo celadon excavated from the kiln sites in the GangJin and Buan areas, the effect of the chemical composition and ionic state of Fe on the colour was evaluated by Mössbauer spectroscopy and chromaticity analysis. According to chromaticity analysis, the L* value (brightness) of the glaze was shown to be affected more by TiO₂ and MnO than by Fe₂O₃, and the body was affected more by Fe₂O₃ than by TiO₂. The a* value was found to be affected by Fe₂O₃ and TiO₂ in the glaze, whereas there was hardly any change in the body according to the composition. As for the b* value, changes due to the composition were shown to be smaller than those for the L* and a* values. According to the Mössbauer spectroscopy results, as the quantities of TiO₂ and Fe₂O₃ are increased, Fe²⁺/Fe³⁺ decreases; while the changes in Fe²⁺/Fe³⁺ with MnO and P₂O₅ are negligible. As the quantity of Fe²⁺/Fe³⁺ increases, the a* and b* values decrease, which results in the change of colour from red–yellow to blue–green. The characteristic green colour can be attributed to increased L* (brightness) and decreased a* and b* values (blue–green shift) due to the reduced Fe ion, which is mainly determined by the TiO₂ and Fe₂O₃ contents.     

Lapis lazuli usage for blue decoration of polychrome painted glazed pottery: a recurrent technology during the Middle Ages in Apulia (Southern Italy)

Seven fragments of atypical proto-majolica from the archaeological site of Siponto (Manfredonia, Foggia) were analysed by chemical and physical methods. All fragments have blue, brown and yellow painted decorations. Raman microscopy and Scanning Electron Microscopy–Energy Dispersed Spectroscopy (SEM–EDS) investigations identified the blue pigment to lapis lazuli. We previously identified this mineral in the blue coloration of the tin–lead glaze of proto-majolica finds at other Medieval sites in Apulia (Castel Fiorentino and Lucera). The discovery of the fragments from Siponto, in spite of their peculiar technological-decorative features, proves that the use of lapis lazuli as a ceramic pigment was not an isolated occurrence, but was quite common in the Middle Ages in the production of typologically heterogeneous ceramics in Southern Italy.     

The Effect of Accelerated Alteration on the Discrimination between Baltic and Romanian Amber

Ten geological samples (five from each source—Romanian amber and Baltic amber) in duplicate for five different media (air, water, saline, acid and basic) were subjected to thermal alteration at 80 ± 2°C for 12 weeks, in the dark. The samples were analysed before and after the accelerated alteration experiment by Fourier transform infrared spectroscopy, both in transmittance and reflectance mode, and the acquired spectra were statistically processed by multivariate data analysis, mainly using principal component analysis. The results of the experiment are useful in giving a better picture of how to discriminate between archaeological amber artefacts.     

Study of the Technique and of the Materials of a 19th‐Century Polychrome Wood Mask from Papua New Guinea

This paper presents the results of the analysis carried out on a polychrome wood mask from Papua New Guinea during conservation work at Pigorini Museum's restoration laboratory. The significance of this study is that no prior work has characterized the painting materials of Papua New Guinea masks both with spectroscopic and internal microstratigraphic analysis. In fact, these objects were studied especially from an anthropological or conservative point of view and the wood was wrongly defined by its visual appearance. Microstratigraphic and spectroscopic investigations discovered a refined execution technique that up to now has not been demonstrated. The stratigraphy of the painted layers demonstrates a deep knowledge of the materials and of the application techniques on the part of the Papua New Guinea people, together with the ability to foresee the aesthetic result for the artefact. The analysis of the constitutive materials and of the stylistic features supplied valid results in favour of provenance of the mask from Papua New Guinea.     

Re-examining the chemical evaluation of diagenesis in human bone apatite

Isotopic analysis of human bone is becoming an increasingly important tool for the archaeologist in divining past life-ways. The isotopic ratios within bone are often assumed to be preserved as in life, but diagenetic change can alter the ratios, invalidating the results of isotopic analysis. Diagenesis can be evaluated in a number of ways, but most often spectroscopic techniques are utilised as the most efficient and easiest to understand methods for the archaeologist. Many isotopic studies do not report the possibility of diagenetic change, and if it is reported it has often been quantified using a single method of chemical analysis, FTIR spectroscopy. This study set out to test the value of FTIR analysis using human remains from the prehistoric site of Ban Non Wat, Northeast Thailand, and to compare the results with the non-destructive technique of FT-Raman spectroscopy. The study shows that FTIR spectroscopic analysis gives far less detail on the condition of bone than Raman spectroscopy, which does not merely indicate recrystallisation has occurred, but also shows clearly whether or not collagen is present, allows identification of ionic substitions which have occurred and identification of secondary minerals which have formed. Raman spectroscopy, combined with LA-ICP-MS analysis also revealed that soil composition and groundwater flow are the conditions which most affect diagenesis at Ban Non Wat.     

An early Iron Age assemblage of faience beads from Ashkelon,Israel: chemical composition and manufacturing process

The microstructure and chemical composition of eight faience beads from an early Iron Age (12th century BCE) assemblage found in the ancient city port of Ashkelon (Israel) are determined by means of FTIR spectrometry, pXRF, microRaman and SEM-EDS analysis. The results are compared with published data of Egyptian and Near Eastern artifacts. Each sample exhibits a hue which is obtained by adding a specific colorant to the glazing mixture. A new gray chalcopyrite-manganese-based colorant was identified. Cementation glazing was most likely used in the manufacturing process of the specimens analyzed, except for the blue bead, which is an Egyptian blue frit. The results suggest that these objects represent a unique assemblage, quite different from contemporary Egyptian and Near Eastern materials, and provide new information regarding the Iron Age faience evidence in the southern Levant.     

A new statistical approach for determining the crystallinity of heat-altered bone mineral from FTIR spectra

The crystallinity of bone mineral represents an established method of measuring heat-induced change and is of importance to fields including material science, clinical science, anthropology and archaeology. A commonly used technique involves the calculation of the Crystallinity Index (CI) using selected peaks from Fourier Transform Infrared (FTIR) absorbance spectra. However, the choice of peaks has to date not been statistically justified. In this study a novel application of statistical techniques to the FTIR spectra of bone samples burned in the range 100 °C–1100 °C has been used to identify 5 new spectral indices of heat-induced crystallinity change. The validity of the new indices was tested by using a statistical classification model (LDA) to predict the burning temperature of a set of 108 bone samples burned between 100 °C and 1100 °C. A correct classification rate (CCR) of 97.2% was obtained when a combination of 4 indices including the CI was used. This was significantly better than the CCR of 66.7% which was obtained when the CI was used on its own.     

Wissenstransfer durch Zentrenbildung. Physikalische Methoden in der Chemie und den Biowissenschaften

From the 1950s to 1970s, physical techniques replaced many classical methods in the chemical and biological sciences. In this development, a novel type of method‐oriented scientists emerged, relying on cooperation with instrument manufacturers and forging close links with science‐funding agencies. Their main engagement was the development of methods and the improvement of instruments, responding to the needs of the chemical and biomedical communities. In the United States, an important institutional locus of such method‐oriented scientists were instrument centers, providing service to regional and national groups of scientific users. This article analyzes the knowledge transfer involved in investigating the Biotechnology Resources Program of the National Institutes of Health, and presenting the example of one of these centers, the Stanford Magnetic Resonance Laboratory.     

马鞍山朱然墓漆砚的实验研究

漆砚是砚台中较为特别的一种,漆木砚、漆砂砚等都是漆砚的不同种类,具有不同的工艺特征。早期漆砚的髹漆工艺较为简单,至明清时期的漆砂砚工艺为漆砚发展的巅峰。为探索古代漆砚工艺,利用显微CT、包埋剖面观察、拉曼光谱和红外光谱,对三国时期朱然墓出土的漆砚进行研究。实验结果表明,这件砚台为大漆直接髹涂在木胎上,砚堂和砚盒的外观颜色为大漆自然色,砚堂边的红色颜料为朱砂,在砚堂漆层中并未发现诸如金刚砂或石英粉之类的研磨颗粒物。该砚台在考古报告中记录为"漆砂砚",漆砂砚工艺仅见于明清时期文献记载,典型特征是用大漆调和颗粒研磨物作为砚堂。因此,三国朱然墓的这件砚台不具备漆砂砚特征,或称之为漆砚更为适宜。同时,本研究的实验结果可为两汉时期的漆砚研究提供参考。