Chemical composition characterization of ancient glass finds from <Emphasis Type="Italic">Troesmis</Emphasis>—Turcoaia,Romania

This paper reports and discusses the chemical composition of 20 glass fragments discovered during the 2012 archeological survey at Troesmis (Turcoaia, Tulcea county, Romania) and dated to the Roman and the Byzantine/Early Medieval periods. The data were obtained by two external Ion beam analysis (IBA) methods—namely Particle-induced X-ray emission (PIXE) and Particle-induced gamma-ray emission (PIGE)—and they were compared to the recognized compositional glass groups from the Mediterranean region during the first millennium AD. The Troesmis assemblage turned out to contain samples belonging to several distinct categories of ancient glass, obtained from different raw materials and manufacturing procedures. Some of the analyzed vitreous finds from Troesmis were the result of glass recycling, while others were identified as deriving from Roman glass vessels imported from the Levantine or Egyptian shores of the Mediterranean. This archeometric study brings additional arguments for the long-range commercial exchanges during the Roman period.     

Analysis of Medieval and Post‐Medieval Glass Fragments from the Dubrovnik Region (Croatia)

Dubrovnik was an important trade city throughout the medieval and post‐medieval time period, maintaining its own glass production from the 14th to the 16th century. Unfortunately, Dubrovnik glass discoveries have not been well investigated up until now, except via archival data in large data analyses. In the following work, we will shed new light on the glass material found in this region, which has diverse origins, chronology, typology and style. Medieval and post‐medieval glass finds (10th/12th–18th centuries) discovered during archaeological excavations in Dubrovnik and the Dubrovnik region were analysed using particle‐induced X‐ray emission (PIXE) and particle‐induced gamma‐ray emission (PIGE), which revealed three main compositional groups: natron glass, plant‐ash glass and potash glass. This demonstrates the important commercial links present between Dubrovnik and other major glass‐making centres.     

SEM-EDS characterization of western Mediterranean obsidians and the Neolithic site of A Fuata (Corsica)

During the Neolithic, obsidians of the Monte Arci (Sardinia) volcanic complex were by far more used in the northern Tyrrhenian area than those of the three other source-islands (Lipari, Palmarola, Pantelleria) in the western Mediterranean. It is shown that merely determinations of content for six major elements with a scanning electron microscope by energy dispersion spectrometry (SEM-EDS) are sufficient to distinguish the four types of Monte Arci obsidians. Because of the compositional similarities between these obsidian types, a multivariate analysis is recommended in provenance studies. Although SEM-EDS, electron microprobe-wavelength dispersion spectrometry (EMP-WDS) and particle induced X-ray emission (PIXE) give essentially concordant results in the determination of these six element contents, subtle technique-related biases prevent the combination of SEM-EDS, EMP-WDS and PIXE data on source samples for provenance purposes. An SEM-EDS test-study reveals the first occurrence of obsidians of Lipari for the A Fuata Middle to Late Neolithic site of NW Corsica (north of Sardinia), in addition to the usual Monte Arci obsidians. Similar to EMP-WDS, the SEM-EDS technique requires only millimeter-sized fragments.     

CAMPANIAN POTTERY FROM ANCIENT BRUTTIUM (SOUTHERN ITALY): SCIENTIFIC ANALYSIS OF LOCAL AND IMPORTED PRODUCTS*

One hundred and fifty-seven sherds of Campanian pottery were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and flame emission spectroscopy (FES). The sherds were found in the course of archaeological excavations carried out at the sites of Sibari, Cosenza, Crotone, Locri, Reggio and Oppido Mamertina in southern Italy (ancient Bruttium, today Calabria). Analyses were carried out on dissolved samples, determining 15 elements per sample (Al, Fe, Ca, Mg, Ti, Mn, Sr, Ba, Cr, Cu, Y, La and Sc by ICP-OES, and Na and K by FES). Analytical data were subject to multivariate statistical treatment by hierarchical cluster analysis and principal components analysis. Results indicated different compositional groups, allowing one to separate suspected imports from Campania, Etruria and Sicily from each other and from likely local products. The latter could be further classified into different groups, comprising imitations of foreign forms as well as original local products.     

Geochemical characterisation of north Asian glazed stonewares: a comparative analysis of NAA,ICP-OES and non-destructive pXRF

The analytical performance of non-destructive portable X-ray fluorescence (pXRF) is compared with that of Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Neutron Activation Analysis (NAA) for the elemental characterisation of a group of glazed stonewares from North-East Asia. As a non-destructive technique pXRF is potentially well suited to the elemental analysis of high value archaeological and museum collections but has yet to be critically evaluated for the analysis of archaeological stonewares. In this study we use multivariate evaluation to compare results from non-destructive pXRF in relation to ICP-OES and NAA analysis for the same group of samples. We conclude that, although pXRF is comparatively limited to a small number of major, minor and trace elements, these are sufficient to identify the same compositional groups as high dimensional ICP-OES and NAA datasets for this assemblage.     

Eighteenth‐Century Meissen Porcelain Reference Data Obtained By Proton‐Beam Analysis (PIXE–PIGE)

Prior to their restoration, the porcelain bodies of broken pieces from 31 authentic Meissen objects of the early 18th century were investigated by proton‐beam analysis. Attention was paid so that the proton beam probed only the bare porcelain paste areas of fractures. Thus, contributions to the measured X‐ray and γ‐ray spectra from adjacent surface glaze were prevented. The chemical compositions, obtained by simultaneous detection of elements with Z ≥ 13 (X‐rays) and lighter elements Z ≤ 14 (γ‐rays), represent rather consistent mixtures of paste ingredients. This result highlights the durable recipes and raw materials used in early Meissen porcelain production in the years 1725–50. Mean concentration values of element oxides, deduced from the detailed measurements, prove suitable for use as a database for Meissen porcelain paste identification. Material authentication of intact objects, without access to the bare porcelain body, is demonstrated by inspection of the white glaze. Unique museum objects are examined in atmosphere and without sampling. A low proton‐beam intensity and a short irradiation time ensure non‐destructive analysis. Simultaneous radiation and backscattered particle detection allow complete composition analysis, using the established ion beam techniques of particle‐induced X‐ray emission (PIXE), particle‐induced gamma‐ray emission (PIGE) and Rutherford backscattering spectrometry (RBS).     

PARTICLE‐INDUCED X‐RAY EMISSION (PIXE) ANALYSIS OF OBSIDIAN FROM TEOTIHUACAN

A collection of 50 archaeological obsidian samples studied in the framework of the Preciudadela Project (Teotihuacan, Mexico) has been analysed using particle‐induced X‐ray emission (PIXE) with the external beam line of the Accélérateur Grand Louvre d'Analyse Elémentaire facility (C2RMF, Paris) and of the Instituto de Física (UNAM, Mexico). This work addresses the provenance of these obsidian samples, with the purpose of determining if they come from the obsidian sources exploited by Teotihuacans (mainly Otumba and Sierra de Pachuca), from other sources, or arrived via commercial exchanges with other regions. For that, the elemental compositions derived from the PIXE spectra have been compared with data published in the literature on the basis of instrumental neutron activation analysis. From the concentrations of selected key elements (Na, K, Mn, Fe, Zn, Rb, Sr, Zr), it was possible to unambiguously assign the provenance of most samples. Many originate from two major sources, namely Sierra de Pachuca (Hidalgo) and Otumba (Mexico), which were the main obsidian deposits used by the Teotihuacans. However, some samples exhibit a compositional fingerprint matching other provenances, i.e., Paredón (Puebla) and Zacualtipan (Hidalgo).     

Investigations of Byzantine glass bracelets from Nufăru,Romania using external PIXE–PIGE methods

The chemical composition of twenty glass bracelet fragments found in Nuf?ru, a Byzantine site from 10th–13th centuries A.D., nowadays located on Romania's territory, has been determined using Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE) in external beam mode. Most of the Byzantine bracelet fragments were identified as “mixed natron-plant ash” soda-lime-silica glasses. The obtained chemical compositions indicated that the manufacturing of these finery items was performed using similar raw materials and techniques, in most of the cases involving colored glass recycling. PIXE–PIGE results highlighted the glass chromophores (cobalt, manganese, copper and iron ions) and provided hints about the mineral pigments used to paint the external surface of some bracelets.     

MULTIANALYTICAL STUDY OF PALAEOLITHIC REINDEER ANTLER. DISCOVERY OF ANTLER TRACES IN LASCAUX PIGMENTS BY TEM*

Palaeolithic and modern reindeer antler were analysed using complementary techniques to evaluate the conservation state of bone material. X‐ray diffraction, FT‐IR spectroscopy, scanning electron microscopy (SEM–EDX) and transmission electron microscopy (TEM–EDX) as well as proton induced X‐ray and γ‐ray emission (PIXE–PIGE) at the particle accelerator AGLAE, C2RMF were applied. This study enabled us to define the chemical and structural features of ancient antler at the micro‐ and nanometre scale and compare them to those of other bone materials such as bone and ivory. Antler is richer in its organic fraction compared to bone and ivory. Its mineral fraction, carbonated hydroxylapatite, shows very specific crystal shapes at the nanometre scale. This specific property allowed us to recognize antler traces in pigment samples originating from rock art paintings in the Lascaux cave, Dordogne, southwestern France, Magdalenian period. Therefore, TEM–EDX is the technique of choice for characterizing antler traces in complex mixtures. In the paint material of Lascaux, antler seems most likely to be a pollutant introduced either by stirring the pigments in water with a piece of antler or by carving antler artefacts next to the preparation of paint material. However, it could eventually be used as a marker of paintings that were created contemporaneously.     

X-ray and neutron-based non-invasive analysis of prehistoric stone artefacts: a contribution to understand mobility and interaction networks

Carbonate-rich archaeological artefacts are difficult to identify and correlate between them and with raw materials of such heterogeneous geological sources, especially when only non-invasive analysis is possible. A novel combination of X-ray and neutron-based non-invasive analysis is implemented and used for the first time to study prehistoric stone idols and vessels, contributing to culture identity, mobility and interaction in the recent Prehistory of Southern Iberia. Elemental composition was obtained by prompt gamma activation analysis (PGAA) and external beam particle-induced x-ray emission (PIXE); homogeneity of the stone artefacts and the presence/absence of internal fractures were obtained by neutron radiography (NR). These atomic and nuclear techniques, simultaneously used for complementary chemical information, have been demonstrated to be of great value as they provide non-destructive compositional information avoiding sample preparation, crucial in so singular and rare objects. The obtained results, especially of PGAA, are very promising and useful in general assessments of provenance. The stone artefacts show signs of both nearby and long-distance procurement, as well as of unknown attribution.     

THE TREASURE OF GUARRAZAR: TRACING THE GOLD SUPPLIES IN THE VISIGOTHIC IBERIAN PENINSULA*

The treasure of Guarrazar, found in the 19th century in Spain, is the most important illustration of the high level of Visigothic jewellery in the Iberian Peninsula. The votive crowns and crosses of this treasure are an arrangement of pierced gold in a Byzantine–Germanic style, decorated with emeralds, garnets, sapphires and other materials. In order to establish the provenance of the gold, we analysed a group of 46 minute samples from the most important pieces kept in Spain for major and trace elements. The combination of PIXE and PIGE with an external 3 MeV proton µ‐beam was used to analyse the samples. Considering the gold sources cited by Pliny the Elder and the composition of contemporary Visigothic coins, we suggest the exploitation of south Iberian mines. Using the same set‐up, we complemented these results with the analysis of 11 emeralds inlaid in items from the Guarrazar jewellery that is kept in France. We suggest the use of European sources unknown to the Romans for these gemstones.     

Obsidian provenance studies in Colombia and Ecuador: obsidian sources revisited

The field occurrences, elemental compositions and formation ages of Colombian and Ecuadorian obsidians are revisited. It is shown that the regional sources of this raw material are linked to two major volcanic structures: the Chacana and the Paletara calderas, localised on the eastern cordillera of Ecuador and on the central Andean cordillera of south Colombia respectively. Seventy-two samples were analysed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), inductively coupled plasma-mass spectrometry (ICP-MS) and/or particle induced X-ray emission (PIXE). The same 10 types of elemental compositions were identified independently from ICP and PIXE. Four of these types were previously unknown. The formation ages of these obsidians previously determined by fission tracks dating are in the range 0.17–1.58 Ma at Chacana and 3.46–4.27 Ma at Paletara. Most Colombian and Ecuadorian pre-Hispanic artefacts present elemental compositions compatible with a Chacana- or Paletara-derived origin of the raw material. However, some of them present fission track ages discordant with the present-day known obsidian occurrences, which implies that the regional source inventory is not yet exhaustive.     

Analyses of Early Medieval Stained Window Glass From the Monastery of Baume‐Les‐Messieurs (Jura,France)

The collection of early medieval window glass found in the abbey of Baume‐les‐Messieurs (Jura, France) is exceptional because it dates to the end of the eighth century, and due to the number of fragments as well as their state of conservation. Different colours and forms have been identified. These pieces are a rare opportunity to address the glass craft, its recipes and techniques for a phase of its history that has remained little known. Analyses in PIXE–PIGE prove that, in addition to fragments from two soda glass items, the pieces are made from wood‐ash glass. Most of them probably came from the same production and the raw material is present in the region. At this early stage of wood‐ash glass production, the glassmakers had mastered the glass as well as the colour processes.     

Elemental characterisation of Barbar ceramics from Tell Abraq

The early second millennium levels at Tell Abraq have yielded over 600 fragments of friable, red-ridged pottery with exploding lime grits which is superficially indistinguishable from contemporary, so-called 'Barbar'pottery on Bahrain (1). The Bahraini origin of the Tell Abraq Barbar sherds has been demonstrated by means of proton-induced x-ray and gamma-ray emission (PIXE/PIGME) analysis. In addition, the results of x-ray fluorescence (XRF) of Barbar pottery from Saar on Bahrain (2) have been re-examined, showing that the subgroups which characterise the Tell Abraq material correspond to those found in the Saar corpus. The techniques used on the Tell Abraq and Saar material – PIXE/PIGME and XRF – are compared.     

A COMBINED MULTI‐ANALYTICAL APPROACH FOR THE STUDY OF ROMAN GLASS FROM SOUTH‐WEST IBERIA: SYNCHROTRON μ‐XRF,EXTERNAL‐PIXE/PIGE AND BSEM–EDS

An integrated, multi‐analytical approach combining the high sensitivity of SR‐μXRF, the light element capability of PIXE/PIGE under a helium flux and the spatial resolution of BSEM + EDS was used to characterize chemical composition and corrosion of glass samples (first to fourth centuries ad ) from an important, but scarcely investigated, Roman region of south‐west Iberia (southern Portugal). The geochemical trends and associations of major, minor and trace elements were investigated to shed light on production techniques, the provenance of raw materials and decay mechanisms. The results, while confirming a production technique common to Roman glasses throughout the Empire—that is, a silica‐soda‐lime low‐Mg, low‐K composition, with glass additives as colouring and/or decolouring agents (Fe, Cu, Mn, Sb)—show at one site high Zr–Ti contents, suggesting a more precise dating for these glasses to the second half of the fourth century. The Ti–Fe–Zr–Nb geochemical correlations in the pristine glass indicate the presence of minerals such as ilmenite, zircon, Ti‐rich Fe oxides and columbite in the sands used as raw materials for the glass former: these minerals are typical of granitic‐type source rocks. The unusually high K content in the corrosion layers is consistent with burial conditions in K‐rich soils derived from the alteration of 2:1 clays in K‐bearing rock sequences.     

SELECTION AND HEATING OF COLOURING MATERIALS IN THE MOUSTERIAN LEVEL OF ES‐SKHUL (c. 100 000 YEARS BP,MOUNT CARMEL,ISRAEL)

The transformation of yellow goethite into red hematite by heating has long been assumed for Palaeolithic red artefacts excavated close to fireplaces. However, this transformation is extremely rare. Using SEM–FEG–EDX, PIXE–PIGE, TEM and μXRD, we characterized the mineralogical and chemical compositions of four microsamples of colouring materials from the Mousterian layer B in the es‐Skhul rock‐shelter, from about 100 kya ago. For some colouring materials, the Mousterian people of es‐Skhul chose to gather remote yellow lumps for heating. Their significant transport distance provides evidence of the possible high cultural value of these colouring materials for transformation into red pigments.     

汝官瓷和钧官瓷主量化学组成的多元统计分析

为了研究多种釉色汝官瓷和钧官瓷的原料来源、成分和分类关系,正确鉴别两窑瓷器,应用质子激发X荧光分析(PIXE)技术测定了一组清凉寺窑汝官瓷片和一组钧台窑钧官瓷片的主量化学组成,应用多元统计分析方法对测试数据进行了分析,结果表明:多数汝官瓷胎、钧官瓷胎样品的原料产地和成分接近但有所不同;汝官瓷釉和钧官瓷釉的原料产地和配方则明显不同;从主量化学组成上可以较好地区分汝官瓷釉和钧官瓷釉样品。分析结果可为深入研究汝官瓷和钩官瓷的原料产地、起源关系、真伪鉴别和提高仿古瓷器的质量等方面提供可借鉴的科学依据。     

The use of SEM-EDS,PIXE and EDXRF for obsidian provenance studies in the Near East: a case study from Neolithic Çatalhöyük (central Anatolia)

In this paper we evaluate the relative analytical capabilities of SEM-EDS, PIXE and EDXRF for characterizing archaeologically significant Anatolian obsidians on the basis of their elemental compositions. The study involves 54 geological samples from various sources, together with an archaeological case study involving 100 artifacts from Neolithic Çatalhöyük (central Anatolia). With each technique the artifacts formed two compositional groups that correlated with the East Göllü Da? and Nenezi Da? sources. The non-destructive capabilities of these methods are emphasized (albeit with certain analytical limitations in the case of SEM-EDS), suggesting important new techniques for Near Eastern obsidian provenance studies.     

Chemical and mineralogical characterization of Aguada Portezuelo pottery from Catamarca,north-western Argentina: PIXE,XRD and SEM-EDS studies applied to surface pre- and post-firing paints,slips and pastes

Particle-induced X-ray emission (PIXE), X-ray diffraction (XRD), electron microprobe analysis (EDS) and scanning electron microscopy (SEM) analytical techniques were used to characterize surface paints in pre- and post-fired Aguada Portezuelo decorated pottery. Surface paintings in black, white, red, brown, burgundy and ochre were analysed. Major, minor and trace elements were detected by PIXE, whereas XRD and SEM-EDS gave information on the main mineral phases and the characteristic morphology for each analysed pigment. The results obtained indicate that the main colour groups can be easily discriminated by PIXE, and they are characterized by only one pigment for each colour: hematite (red) and manganese mineral oxides (black), respectively, whereas white pigments are characterized by calcite, ghelenite and gypsum.     

中国古墨与现代墨元素成分研究

对中国古墨（汉墨、明墨与清墨）与不同产地的现代墨元素成分作了对比分析。用离子背散射测定墨中常量元素C、N、O的含量,用质子激发X荧光法测定微量元素K、Ca、Ti、Cu、Fe等10种元素的含量。实验结果表明,古墨中微量元素K、Ca的含量比现代徽墨、沪墨高10倍以上,而现代徽墨与沪墨中元素N和An的含量也有明显的差别。