ANALYTICAL CHARACTERIZATION OF ROMAN PLASTERS OF THE ‘DOMUS FARINI’ IN MODENA*

The paper refers to the analytical characterization of Roman painted plasters dating back to the second century ad . The following techniques were used: optical microscopy (OM), scanning electron microscopy (SEM–EDS), micro‐Raman and Fourier transform infrared spectroscopies (µ‐Raman and FT–IR), X‐ray diffraction (XRPD), colorimetry and thermal analyses (TG/DTA). The investigation analysed the chemical composition and structure of the plasters, the chemical composition of the pigment layers, the use of binders and any chemical alteration of pigments as well as deterioration of the samples. Stratigraphic analysis of plasters allowed identification of their individual components, which proved helpful in finding out more about the mural painting technique employed.     

COOKING AND PAINTED WARE FROM SAN GIUSTO (LUCERA,FOGGIA): THE PRODUCTION CYCLE,FROM THE SUPPLY OF RAW MATERIALS TO THE COMMERCIALIZATION OF PRODUCTS*

Archaeological excavation at the San Giusto site (Lucera, Italy) has unearthed a Late Antique kiln that was most certainly dedicated to the production of cooking ware. An archaeometric study of numerous specimens of cooking and painted ware found at this site was carried out using optical microscopy, scanning electron microscopy, micro‐Raman spectroscopy, X‐ray diffraction, X‐ray fluorescence, inductively coupled plasma mass and optical emission spectrometry and instrumental neutron activation analysis. The integration of historical–archaeological data with archaeometric data has revealed that these specimens can be attributed to the San Giusto site. Furthermore, the production cycle of this ware can thus be reconstructed: from the diversified supply of raw materials (fluvial and marine sediments), to the relatively complex preparation of the paste, to firing at variable temperatures (600–750°C for cooking ware; 850–1050°C for painted ware).     

A MULTI‐ANALYTICAL APPROACH FOR THE CHARACTERIZATION OF COMMODITIES IN A CERAMIC JAR FROM ANTINOE (EGYPT)*

This paper describes a multi‐analytical chemical study performed on the original, almost totally conserved, content of a small ceramic jar from the Antinoe archaeological site (fifth to seventh centuries ad, Roman Egypt) and now belonging to the archaeological collection of the Istituto Papirologico ‘Girolamo Vitelli’ (Florence, Italy). Scanning electron microscopy with an energy‐dispersive X‐ray spectrometer (SEM–EDX), Fourier transformed infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) were all used to characterize the inorganic components of the archaeological material. The organic substances were analysed using FTIR, direct exposure mass spectrometry (DE–MS) and gas chromatography – mass spectrometry (GC–MS). The inorganic component essentially consisted of halite (NaCl). Among the NaCl crystals, lamellar elements were identified. They were chemically characterized by carbonato‐apatite and showed a concentric morphology typical of the scales of small fish. The most prevalent organic constituents of the sample were monocarboxylic acids, α,ω‐dicarboxylic acids, and cholesterol and its oxidation products. The organic material composition was consistent with the occurrence of lipids of animal origin. In addition, diterpenes related to pine pitch were also identified. The overall results suggest that the material recovered in the small ceramic jar found in Antinoe is a residue of fish‐based pickles such as garum, muria, allex and liquamen, which were commonly used in Roman times.     

Physico‐Chemical Characterization of Pigments and Binders of Murals in a Church in Ethiopia

Here, we report the physico‐chemical characterization of wall paintings from the Petros and Paulos church in Ethiopia. This work represents the first technical study of paintings located in Ethiopia, rather than paintings in museum collections outside the country, using diverse analytical techniques. In situ examination with a portable X‐ray fluorescence spectrometer (pXRF) was followed by analysis of samples using optical microscopy (OM), scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy (SEM/EDS), micro‐Raman spectroscopy (MRS), attenuated total reflection – Fourier transform infrared spectroscopy (ATR‐FT–IR), X‐ray powder diffraction (XRD) and pyrolysis gas chromatography – mass spectrometry (Py‐GC/MS). The paint stratigraphy, the compositions of the support material, the preparatory and painting layers were studied, as well as the morphology of the pigment particles. The results revealed the use of earth pigments and carbon black. The preparatory layer was uncommon; composed of dolomite, clay rich in clinochlore and sand, in contrast to the more common gypsum and calcite. The binder and the stratigraphic analyses suggested a distempera technique.     

RELATIONSHIP BETWEEN THE COLORATION AND THE FIRING TECHNOLOGY USED TO PRODUCE SUSA GLAZED CERAMICS OF THE END OF THE NEOLITHIC PERIOD*

Ancient decorated potteries from Susa (Mesopotamia) dating from 4200 to 3700 bc , were studied in order to determine the origin and the nature of the raw materials used, and to identify the technological processes applied to make the ceramic bodies and their decorations. Bulk compositions were determined by particle induced X‐ray emission (PIXE), while the microstructure and the mineralogical phases were studied using scanning electron microscopy (SEM), energy dispersive X‐ray analyses (EDX) and X‐ray powder diffraction (XRD). The results showed that the raw materials used to elaborate these potteries were similar for all the ceramic bodies (carbonates and iron and magnesium‐rich clays containing sand), and for all the decorations (iron oxides, silica, potassic and alumina sources). The variations of coloration of the ceramics and of their decorations were due to different firing temperatures. The ranges of firing temperatures used by potters were evaluated on the basis of mineral stability domains.     

FIELD AND LABORATORY MULTI‐TECHNIQUE ANALYSIS OF PIGMENTS AND ORGANIC PAINTING MEDIA FROM AN EGYPTIAN COFFIN (26TH DYNASTY)

This paper describes the physico‐chemical analyses performed on an Egyptian wood coffin on the occasion of its restoration in the hall of the National Archaeological Museum of Parma (Italy), with the aim of investigating the pigments and organic materials originally used. Pigment determination was performed both in situ by a portable energy‐dispersive X‐ray fluorescence (EDXRF) spectrometer and in the laboratory using a micro‐Fourier‐transform‐infrared (micro‐FTIR) and a Fourier‐transform (FT) Raman spectrometer. The identification of organic materials was performed through gas chromatography – mass spectrometry (GC–MS) and micro‐FTIR analysis. Amongst the pigments, special attention was paid to the green, which appeared to be severely degraded and was examined using powder X‐ray diffraction (XRD) and scanning electron microscopy – energy‐dispersive X‐ray (SEM–EDX) in addition to the above‐cited techniques. Other materials used in the polychromatic decorations are Egyptian blue, cinnabar and possibly orpiment, while calcium carbonate was used for the ground layer. The organic materials were identified as beeswax, mastic and gum arabic, sometimes as mixtures.     

CHARACTERIZATION OF LATE CHALCOLITHIC MICRO‐BEADS FROM ÇAMLIBEL TARLASI,NORTH‐CENTRAL ANATOLIA

Micro‐bead manufacture is geographically widespread from the fifth millennium bc . Previous studies of comparable micro‐beads from sites in the Indus Valley region and the Near East suggest that many of these beads were formed from synthetic enstatite. Characterization of micro‐beads from the Late Chalcolithic site of Çaml?bel Tarlas? was carried out by optical microscopy (OM), scanning electron microscopy (SEM) and microanalysis with energy‐dispersive X‐ray spectroscopy (EDS), and X‐ray diffraction analysis (XRD). The chemical composition of the micro‐beads analysed indicated that they were made from three distinctive materials; namely, bulk talc (i.e., synthetic enstatite precursor), apatite and mineral‐rich clay pastes.     

A SCIENTIFIC INVESTIGATION ON THE PROVENANCE AND TECHNOLOGY OF A BLACK‐FIGURE AMPHORA ATTRIBUTED TO THE PRIAM GROUP*

The restoration of a Greek black‐figure amphora provided an opportunity to study the provenance and production technology of the vase. The composition of the ceramic body, determined by inductively coupled plasma optical emission spectroscopy (ICP–OES), matches that of Attic products. Investigation by X‐ray diffraction and reflectance spectroscopy suggests a maximum firing temperature around 900°C and a body re‐oxidation temperature around 800°C, respectively. The morphology and composition of black, red and dark red surface areas were studied by scanning electron microscopy and X‐ray energy‐dispersive analysis; the black areas show the features of a typical well‐vitrified black gloss, while the red areas were most probably obtained by simple burnishing of the body; the dark red additions, on the other hand, are the likely result of a partial re‐oxidation of a clay–ochre mixture.     

Archaeometric Investigation of Medieval Pottery from Excavations at Novo Brdo,Serbia

Medieval pottery from excavations at Novo Brdo, Serbia, an important mining and trading centre during the 14th and 15th centuries, was investigated by a combination of optical microscopy, inductively coupled plasma – optical emission spectrometry, Fourier transform infrared, micro‐Raman and energy‐dispersive X‐ray fluorescence spectroscopy and X‐ray powder diffraction methods in order to determine its composition and firing temperature. The samples investigated were made of medium‐ to coarse‐grained, non‐calcareous clay, by a relatively well‐controlled firing procedure in an oxidizing atmosphere. The firing temperature was estimated to be 850–950°C. The similarity between the chemical composition of the investigated pottery and the local raw clay, combined with the outward appearance and the archaeological findings, indicate domestic production. The pottery is covered with the transparent lead‐rich glaze. Iron and copper were used as colourants.     

The Structure and Chemical Composition of Wall Paintings From Islamic and Christian Times in the Seville Alcazar

Wall paintings from the Islamic epoch (10th to 12th centuries) and the Christian monarchy (14th to 16th centuries) have been recovered in discarded materials and on walls after reconstruction works in the Seville Alcazar. These paintings have spent centuries underground or under a plaster coat. Portable X‐ray fluorescence (XRF) and combined XRF/X‐ray diffraction (XRD) were employed in situ, as well as scanning electron microscopy (SEM–EDX), grazing angle incidence XRD and micro‐Raman spectroscopy, on cross‐section samples to fully characterize the materials in the wall paintings. Using these methods, the fresco technique was demonstrated, and many kinds of pigments were identified in accordance with the various periods of the history of the Alcazar, thus assessing the authenticity of all the wall paintings studied here.     

Thermal and Petrographic Characterization of Herculaneum Wall Plasters

Roman plasters sampled from different houses at the archaeological site of Herculaneum, Italy, (2010–12) were studied by means of petrography, thermal analysis and X‐ray fluorescence. Herculaneum plasters are composed by preparatory layers (arriccio) with a thickness of several centimetres and are based on a calcitic binder and volcanic scoriae as aggregates, covered by a thin final layer characterized by a low granulometry. Most of the sampled plasters can be placed into two groups based on the aggregate composition and classified as marmorino or intonachino. However, a similar aggregate composition did not induce superimposable thermal behaviour, thus suggesting that the samples underwent different ageing/weathering processes, with a consequent change of the ratio among the components.     

THE CHARACTERIZATION OF PAINTS AND WATERPROOFING MATERIALS FROM THE SHIPWRECKS FOUND AT THE ARCHAEOLOGICAL SITE OF THE ETRUSCAN AND ROMAN HARBOUR OF PISA (ITALY)*

This work presents the results of a diagnostic survey on the shipwrecks from the archaeological site of the ancient harbour of San Rossore (Pisa, Italy). The original waterproofing, caulking and painting materials were characterized by Fourier transform infrared spectroscopy (FTIR), gas chromatography – mass spectrometry (GC–MS), energy‐dispersive X‐ray microanalysis (EDX) and X‐ray diffraction (XRD). The major constituents of the waterproofing and caulking materials detected on the planks were tricyclic abietanes showing a high degree of aromatization. These compounds are indicative of a pitch obtained from the wood of trees of the Pinaceae family. The analysis of the organic components of the paint samples revealed diterpenoid acids characteristic of Pinaceae resins together with linear long‐chain alcohols and fatty acids, highlighting the presence of beeswax. Noticeably, the characteristic odd carbon number alkanes that are normally present in beeswax were not detected. The EDX and XRD analyses showed that hematite, calcite, cerussite and kaolinite were employed as pigments to paint the ships’ hulls.     

Multi‐analytical Studies of Archaeological Chinese Earthen Plasters: The Inner Wall of the Longhu Hall (Yuzhen Palace,Ancient Building Complex,Wudang Mountains,China)

The Yuzhen Palace is one of the nine palaces in the Ancient Building Complex built by order of the Yongle Emperor during the Ming dynasty. The buildings were built with dressed black bricks. As a result of the planned national South–North Water Diversion project, the water level in the Danjiangkou Reservoir that surrounds the Yuzhen Palace was expected to rise by approximately 15 m. To avoid submersion of the site, three gates were elevated by 15 m in 2013 and other buildings dismantled, for later reconstruction. The characterization of the construction materials has therefore become of primary importance. Here, we present results on the plasters of the Longhu Hall. The analysis of materials involved a multi‐analytical approach combining optical and electron microscopy with X‐ray and vibrational spectromicroscopies and thermogravimetry. The results indicated the use of two earthen plaster layers and a whitewash finish coating applied over a thin preparatory intermediate layer to improve the adherence of the finish coating to the earthen plaster. Ramie and straw fibres identified in the earthen plasters were added to reduce shrinkage and cracking during drying. The raw materials used and the application technique pointed to a well‐established construction industry using traditional earthen building materials together with lime technology.     

SCIENTIFIC INVESTIGATION OF FAIENCE FRAGMENTS ATTRIBUTED TO THE TOWN MOSAIC AT KNOSSOS*

We analysed a faience fragment from Bristol Museum and Art Gallery, to determine whether it belonged to the Town Mosaic, excavated at Knossos. Three Town Mosaic fragments from the Ashmolean Museum, Oxford were also examined. The objects were analysed using non‐destructive variable‐pressure scanning electron microscopy with energy‐dispersive X‐ray spectrometry. The Bristol object's composition and microstructures are similar to those of the Town Mosaic samples. Our results are also comparable to those from polished samples of Minoan faience (Tite et al. 2009 ), showing that VP SEM–EDX gives reliable results without invasive sampling. Silicaceous, copper‐rich microspheres were identified for the first time in two of the Ashmolean objects.     

Microstructural and Componential Characterization of the Plating Technology on Chinese Han Dynasty Bronze Fragments

The bronze wares of the Han Dynasty excavated in Chongqing are decorated with plating patterns, maintaining an exquisite lustre right up to modern times after the covering patina is cleared away. In this paper, a plated fragment of the Han Dynasty from the Wushan County Museum was characterized by combining optical microscopy (OM), scanning electron microscopy with X‐ray energy‐dispersive spectrometry (SEM–EDS), X‐ray fluorescence analysis (XRF), X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). The results showed that the bronze fragment was gilded with a ~ 3 μm thick gilded layer and a ~ 20 μm thick silvered layer. The high concentration of Hg and Hg‐rich intermetallic compounds confirmed the existence of mercury gilding/silvering technology, for example, Au₉Hg in the gilded layer and Ag₁₃Hg₇ in the silvered layer. An ordered stripe structure was observed in the gilded surface, corresponding to the formation of rod‐like, intermetallic Au–Hg compounds. Specifically, a high concentration of Au was detected in the silvered layer. The exploration of gilded/silvered bronze casts light on this ancient technology and the benefit of identifying, protecting and reproducing it.     

Never Judge A Gold Object by Its Surface Analysis: A Study of Surface Phenomena in a Selection of Gold Objects From the Staffordshire Hoard

With the introduction of commercially available handheld XRF analysers, there is a growing problem that the results, simply taken at face value, are regarded as representative of the bulk gold alloys of the objects analysed in museums and used for treasure analysis. It is well known that surface analysis is problematic, and the aim of this study was to test whether non‐destructive surface analysis could be useful in grouping the very large numbers of fragmentary pieces in the Anglo‐Saxon Staffordshire Hoard. Surface and subsurface analyses of 16 objects from the Hoard were carried out by X‐ray fluorescence (XRF) and scanning electron microscopy with energy‐dispersive X‐ray analysis (SEM–EDX). The results indicate that there are significant but inconsistent levels of enrichment of the gold at the surface of many of these objects, due to the loss of both copper and silver. The significant loss of silver (up to 50% relative in some cases) suggests that some form of deliberately induced depletion gilding was carried out during manufacture to remove both silver and copper from the surface. In three cases, an increase in silver at the surface compared to the core metal was detected: this might tentatively be explained by redeposition from contact with silver objects during burial. These results have clear implications for the reliability and interpretation of surface analysis data of gold alloys from this period.     

CHARACTERIZATION AND PROVENANCE OF LIME PLASTERS FROM THE TEMPLO MAYOR OF TENOCHTITLAN (MEXICO CITY)

In this work, we present the results of the analyses of 20 lime plaster samples taken from the Templo Mayor (Great Temple), the main pyramid of Tenochtitlan (Mexico), the ancient capital of the Mexicas. The samples were analysed to recover information on the mixtures used in the fabrication of the plasters and for the provenance of the raw materials (in particular, limestone) used to make the plasters. The characterization of the samples was done by OM, SEM/EDS, XRF and LA–ICP–MS analyses, while the identification of the provenance of raw materials was done by studying the lumps present in the samples with LA–ICP–MS. The objective of the study was to establish if there was a relationship between changes in the construction techniques employed in the pyramid over time and if there were changes in the provenance of the raw materials. Six different construction phases of this pyramid are analysed, showing the similarities and differences among them, mainly based on differences in the sieving of the aggregates and in the raw materials employed. The provenance studies of the limestone used to make the plasters demonstrated that all the limestone comes from the Tula region.     

Preliminary Characterization of Pottery by Cathodoluminescence and SEM–EDX Analyses: An Example from the Yeha Region (Ethiopia)

Yeha was a political and cultural centre of the Ethio‐Sabaean culture (D’MT) in northern Ethiopia and southern Eritrea. Part of the archaeological research deals with pottery of local, regional and imported origin. The research—investigations and examinations—tries to classify local pottery in two ways: first, by analysing the mineralogy of the temper using light microscopy and cathodoluminescence; and, second, by analysing the main element composition of the clay matrix using a scanning electron microscope with energy‐dispersive X‐ray detection (SEM–EDX). The cathodoluminescence shows that the temper material has differences in the colours of feldspars with a similar mineralogical composition. The results demonstrate that the pottery was produced by using local material that originates from various sources in the Yeha region and that the same raw materials were used in different types of pottery.     

PROVENANCE OF OBSIDIAN EXCAVATED FROM LATE CHALCOLITHIC LEVELS AT THE SITES OF TELL HAMOUKAR AND TELL BRAK,SYRIA*

X‐ray fluorescence and laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) analyses conducted on 40 obsidian samples from the Late Chalcolithic 2 levels at Tell Hamoukar and Tell Brak in north‐east Syria have shown trends towards the exploitation of obsidian sources in the eastern Taurus. While the Bingöl region appears to provide the majority of obsidian to both sites, there is also evidence of more minor exploitation of a source in the Lake Van area and an altogether unknown source (X). This paper presents the data acquired from the analyses of the archaeological obsidian and situates these results within their chronological and regional contexts.