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.     

Biomass Spectrometry Identification of the Fibre Material in the Pall Imprint Excavated from Grave M1, Peng‐state Cemetery,Shanxi, China

In order to identify the fibre material of the pall imprint excavated from the Peng‐state cemetery in Shanxi, biomass spectrometry was applied to determine the amino acid sequences of the residual protein extracted from the soil underneath the imprint. The sequences were searched against a standard protein sequence database. A well‐preserved silk pall sample from the Warring States Period was used as a comparative template. The protein extracted is identified as silk fibroin (Bombyx mori). This finding indicates that the extremely degraded pall was made of silk and that the deceased in the Peng‐state cemetery enjoyed high social status. In this way, a novel methodology, which is very promising in uncovering the origin of silk, could be initiated.     

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.     

Fish ’n chips: ZooMS peptide mass fingerprinting in a 96 well plate format to identify fish bone fragments

Fish are a large, highly diverse, and anthropologically important group of vertebrates. However, fish bones are underrepresented in the archaeological literature because they are less stable than those of other taxa and identification of bone to species is often difficult or impossible. We explore a new identification system, ZooMS (Zooarchaeology by Mass Spectrometry), which is based upon protein barcoding. As proteins can be cleaved enzymatically and analyzed by mass spectrometry in a repeatable way, protein barcoding is used widely in microbiological contexts for quick and inexpensive protein identification; mass spectra reflect the differences in protein sequence and can therefore be reproducibly linked to a particular protein or protein fragment. ZooMS uses peptide fingerprinting of bone collagen as a method for rapid identification of archaeological bone. This has involved the identification of masses related to peptides of known sequence. For mammals, sufficient sequence information is available for this approach but for groups, such the teleost fish, species are highly diverse and there are few available collagen sequences. Here we report a preliminary investigation into the identification of fish species by peptide mass fingerprinting that does not require sequence information. Collagen mass spectra are used to identify eight species of bony fishes (Osteichthyes) from four orders: Clupeiformes, Salmoniformes, Gadiformes, and Perciformes. The method is applied to both modern and archaeological fish remains and offers the capacity to identify traditionally unidentifiable fish fragments, thus increasing the Number of Identified Specimens (NISP) and providing invaluable information in specialized contexts.     

In search of the optimum Raman/IR signatures of potential ingredients used in San/Bushman rock art paint

Vibrational spectroscopy (Raman and FTIR) has played an important role in identifying pigments, substrata and deterioration products in rock art studies worldwide: in the laboratory and on-site. However, the detection of organic binders and carrying agents has so far been scarce and the quality of many spectra recorded on-site inadequate. In this study, possible pigments (charcoal, ochre, raptor faeces, thermally treated ostrich egg shell, etc.), binders (fat, egg, blood) and carrying agents (saliva, gall, egg, water) were selected based on artistic considerations and analysed with FTIR and Raman (514.6 and 785 nm excitation, both available in mobile instruments) spectroscopy in order to determine usable marker bands for each ingredient. The resultant marker bands were then used to analyse five ten year old San replica paints. It was found that FTIR spectroscopy is very efficient to identify organic compounds as there is no fluorescence but the broadness of the bands inhibits the exact assignment of many ingredients. A high fluorescence background experienced for many natural products prevented the recording of Raman spectra for all ingredients, in many instances though the sharp peaks usually associated with Raman spectra make identification easier than with FTIR spectroscopy. Most of the ingredients in the paints could be identified, but it is clear that better results are obtained when more that one technique is used.     

Earthenware production and distribution in the prehispanic Philippine polity of Tanjay: results from laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

This paper presents the results of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis of low-fired earthenware from the prehispanic trading polity of Tanjay (c. A.D. 500–1600) in the central Philippines. The goal of this project was to determine whether or not the compositional analysis of ceramics could be used to examine the organization of pottery production and exchange relationships in the Bais-Tanjay region of Negros Island. Results indicate that at least five distinct groups of ceramics can be differentiated based on elemental compositions and that pottery production was both a part-time, dispersed endeavor and a full-time, likely centralized, craft. In addition, a number of compositional outliers in the ceramic dataset suggest that interregional trade took place, with pottery made outside the Bais-Tanjay region being imported, especially by upland swidden farmers.     

Identification of colourants in icons of the Cretan School of iconography using Raman spectroscopy and liquid chromatography

The stratigraphies of twenty five (25) samples removed from twenty (20) icons of the Cretan School of iconography are studied using Optical Microscopy and micro-Raman spectroscopy. The objects are dated in 15th–17th c. and belong to the collection of the Benaki Museum, Athens, Greece. Cinnabar, red ochre, minium, yellow ochre, azurite, malachite, lapis lazuli, lead white, carbon black, and indigo are identified in the cross-sections of the icon samples using Raman spectroscopy.     

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.