Investigating ancient technology and ceramic composition at Al-Khidr site (Failaka Island,Kuwait): Geochemical analyses of Bronze Age pottery by pXRF and thin-section petrographic analyses

Pottery assemblages from the site of Al-Khidr on Failaka Island, Kuwait, were analysed in order to reconstruct the chemical composition of Bronze Age wares and to build a mineralogical database of Bronze Age pottery dated from Failaka Periods 1–3B (2000–1650 BCE). A total of 145 ceramic sherds from Al-Khidr, as well as reference groups, were analysed by non-destructive portable X-ray fluorescence (pXRF) spectrometry. Preliminarily petrographic thin-section analysis was applied to four samples to reconstruct possible clay paste recipes and to identify raw materials. The results indicate that geochemical analyses can successfully distinguish subgroups within a typological category of ceramic assemblages. The results identified two subgroups within the Al-Khidr typological category: the Dilmun Barbar tradition and the Mesopotamian tradition. Future comparative compositional studies can be conducted to explore other aspects of craft specialisation, such as ceramic technological choices and possibly the influence of sociopolitical units.     

INCISED SLIPWARE PRODUCTION AT CASTELFIORENTINO (FLORENCE): THE ‘VIA BERTINI’ SITE (15TH–17TH CENTURIES)*

This study deals with the physical–chemical and mineralogical–petrographic investigations (OM, SEM–EDS, EPMA, ICP, XRpD, Mössbauer and IR) conducted on first‐ and second‐firing wasters belonging to two types of incised slipware (sgraffito), manufactured at Castelfiorentino between the late 15th and the early 17th centuries. Raw materials, colouring agents and firing products were analysed in order to establish the production technology of the ceramic coatings, by means of detailed microtextural and chemical investigations. The pottery underwent two firing processes: the firing of the white slip‐coated ceramic body and a further firing after application of the glaze. The homogeneity of the raw materials, white slip and glaze is remarkable, and demonstrates the use of well‐established recipes with a constant supply of raw materials from the same places. Highly efficient kiln management during both firings is revealed by body–glaze interface reactions.     

A characterisation study of Ubaid period ceramics from As-Sabbiya,Kuwait, using a non-destructive portable X-Ray fluorescence (pXRF) spectrometer and petrographic analyses

The Ubaid cultural phenomena (6500–4200 BC) of southern Mesopotamia has been used to characterise other archaeological sites in the Arabian Gulf region. The aim of this inquiry is to explore the nature of the interaction between the homeland of the Ubaid and the wider Gulf region. Through the use of a non-destructive portable X-ray fluorescence (pXRF) spectrometer, this study seeks to characterise and identify the chemical and mineralogical compositions of the ceramic assemblage from the Bahra 1 site of the As-Sabbiya region, Kuwait. The chemical results demonstrated that a combination of six trace elements [rubidium (Rb), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb) and barium (Ba)] occur significantly enough to delineate clay-based artifact groups—local red coarse from Ubaid, while the mineralogical analysis confirms the pXRF result and identifies the source of the raw materials and temper as well. Also, the comparison between the Ubaid and Bronze Age assemblage results suggests that potters used different clay resources within their own regions and/or production techniques.     

Using provenance data to assess archaeological landscapes: an example from Calabria, Italy

Ceramic provenance studies have helped archaeologists examine trade and exchange in multiple scales, the organization of production, and even vessel function. Yet, they may go even further, to provide a venue for the examination of past people’s perception of their landscape. To do so, a methodology is needed that links the choices prehistoric potters made, as reflected in their ceramics, with the choices their landscape could afford them, as reflected in the extent and distribution of local clays, and the physical, chemical and mineralogical characteristics of these clays. Using the region of Bova Marina in southwestern Calabria as a case study, we have combined a raw materials survey with field and laboratory experiments, along with chemical and mineralogical analyses of the collected sediments to understand the distribution and the physical, chemical and mineralogical variability of locally available clays and provide baseline data against which prehistoric ceramic materials from the region may be compared. We show that the local sediments can be divided into three major units, based on their macroscopic, mineralogical and chemical characteristics, that correspond well with the major geological units outcropping in the study area. While two of these units have internally consistent properties, the third is variable.     

A new protocol for the chemical characterisation of steatite – two case studies in Europe: the Shetland Islands and Crete

Steatite has been one of the most difficult materials of archaeological interest to characterise by physico-chemical methods of analysis with a view to identifying its origin. This paper presents a new protocol for the chemical characterisation of steatite based on the analysis by ICP-MS in tandem with INAA of rare earth elements (REE) and some transition metals in geological steatite from several outcrops on the Shetland Islands and on Crete. The major advance over earlier work has been the secure determination of REE at low concentrations. The results have demonstrated the ability to discriminate chemically three of the known Viking Age sources on Shetland. On Crete, although the situation is complex, four sources in the centre of the island have been partially differentiated. This study has also shown that first mineralogical analysis (by XRD) of steatite provides valuable supplementary characterisation data, and second strontium isotope analysis has promising potential for the sourcing of steatite.     

PETROGRAPHIC AND CHEMICAL CHARACTERIZATION OF POTTERY PRODUCTION OF THE LATE MINOAN I KILN AT HAGHIA TRIADA,CRETE*

Pottery from the Late Minoan I kiln at Haghia Triada in the Mesara Plain, southern Crete, was analysed by a range of techniques, comprising thin‐section petrography, scanning electron microscopy, X‐ray diffraction, X‐ray fluorescence and neutron activation analysis. The project characterizes the ceramic fabrics and probable raw materials, correlates paste recipes with shape, reconstructs the firing conditions of the kiln and establishes a chemical reference group, taking into account post‐burial alteration and contamination. Comparison of the reference group formed with that from the neighbouring, broadly contemporary, kiln at Kommos shows an unexpected differentiation of the two kilns.     

New Insights into the Calcium Flux Used in Ancient Longquan and Yue Kilns Based on Strontium Isotopic Compositions

The glazes of seven types of greenware produced in the Yue and Longquan kilns between the Tang dynasty and the Ming dynasty (ad 618–1644) were studied for their strontium isotopic compositions and bulk chemical compositions. The aim was to identify the raw materials used as the calcium fluxes in the glaze recipes and whether the raw materials changed over time, particularly before and after the Southern Song dynasty (ad 1127–1279). From this work, botanic ash has been identified as the raw material used as the calcium flux in all the seven glaze types studied, and some related ceramic historical issues are also discussed.     

The geochemical diversity of neogene clay deposits in Crete and its implications for provenance studies of Minoan pottery*

The determination of provenance probably forms the primary role of geochemical analyses in archaeological ceramic studies. In what has comprised a successful field of study, the ultimate basis for such research has been the comparison of pottery compositions with the geochemical diversity displayed by clay deposits within a given study area. Although such studies are now common, the understanding of chemical and mineralogical variability in ceramic raw materials has been somewhat neglected, with the dominance of assumptions rather than the actual analysis of clays. In this paper, a study is presented of Neogene clays in Crete (Greece), a clay type commonly used in ancient and modern pottery production. Sixty‐one samples were taken from 28 locations in the central and eastern parts of the island, to reveal both intra‐ and inter‐deposit variability. In one deposit chosen for multiple sampling, the 14 samples display great variability in the alkali elements, Fe and Co, and to a lesser extent in the REEs. Many of the geographically separate deposits differ from each other in chemical composition, with Eastern Cretan deposits showing higher REE concentrations and higher Th/Sc ratios, whereas Central Cretan deposits of younger geological stages are characterized by a lower Th/U ratio. Mineralogical analysis by XRD is used to explain aspects of the geochemical variability of the clays.     

Geochemical signatures of Roman amphorae produced in the Sado River estuary,Lusitania (Western Portugal)

Several archaeological sites located in the Sado estuary, Lusitania province (Western Portugal), show evidence of an important amphorae production, mainly related to the Roman Tróia industrial centre of fish preserves. The chemical analysis of amphorae sherds found in Barrosinha, Bugio, Zambujalinho, Xarrouqueira and Vale da Cepa (Lower Sado) was performed by instrumental neutron activation analysis, and the mineralogical composition obtained by X-ray diffraction. The chemical results were compared with amphorae from the Herdade do Pinheiro production centre, also located in the Sado estuary. Application of several exploratory and discriminant techniques of multivariate statistical analysis using chemical data of Lower Sado amphorae allowed the characterization and differentiation of two reference groups, named Sado 1 and Sado 2. The geochemical patterns and the mineralogical composition of these groups indicate the use of two different raw materials, the selection of which appears to have been based on the proximity factor of the kilns. The amphorae produced in the Sado basin were differentiated from amphorae from the Gualdalquivir estuary (Villa Nueva, Cádiz, Spain) in Baetica province.     

HISPANO-MORESQUE POTTERY PRODUCTION OF THE FOURTEENTH-CENTURY WORKSHOP OF TESTAR DEL MOLÍ (PATERNA,SPAIN)

Excavation of Testar del Molí, the only workshop found in the Manises-Paterna area, revealed the existence of a fourteenth-century ceramic workshop covering the remains of the thirteenth-century workshop. This study is concerned with the fourteenth-century production, and forthcoming papers will connect both epochs following the findings of current excavations. The chemical and mineralogical characterization of the ceramic production of this workshop shows the presence of three groups of ceramic pastes which could also be distinguished by, and, thus, related to, their daily use. The raw materials found in the excavation have also been mineralogically and chemically characterized, and a model of possible mixtures of raw materials has also been developed in order to determine their possible use in the manufacture of the pottery previously characterized.     

GEOCHEMICAL CHARACTERIZATION OF ARCHAEOLOGICAL LIME MORTARS: PROVENANCE INPUTS*

Chemical and mineralogical analyses were carried out on historical lime mortars from the parish church of Santa María La Real (Guipúzcoa). The study included various periods ranging from Roman to modern times and allowed the identification of various types of raw materials. In order to obtain pure binder, free of carbonate aggregates and charcoal particles, an innovative binder separation method was implemented. The chemical composition of the binder allows discrimination of different provenance areas for the raw materials, although those areas do not correlate with specific historical periods. In addition, the influence of burial processes on the primeval chemical features has been assessed and reveals that modern mortars display greater chemical modification than the Roman mortars.     

Mineralogical analysis and provenancing of ancient ceramics using automated SEM-EDS analysis (QEMSCAN®): a pilot study on LB I pottery from Akrotiri,Thera

A wide range of existing mineralogical and geochemical methodologies such as optical microscopy, X-ray diffraction, manual scanning electron microscopy, ICP-MS and INAA have been utilised in the analysis of ancient ceramics, in attempts to elucidate patterns of regional trade and interaction. However, advances in automated scanning electron microscopy with linked energy dispersive spectrometers (SEM-EDS) have created the potential to offer a seamless combination of textural and mineralogical data based on the acquisition of energy dispersive spectra that has so far been unattainable with existing techniques. In this pilot study on pottery from the Cycladic Bronze Age site of Akrotiri (Thera), we have quantified the mineralogy of the ceramics based on automated SEM-EDS using QEMSCAN^® technology and imaged the textures of the ceramics through compositional mapping. Thirteen samples were analysed and, based upon the automated analysis, four groups of ceramic compositions are defined. These data are consistent with, but also refine, previous traditional petrographic examination of the ceramic samples, and enable the likely provenance of the raw materials used in the ceramic manufacture to be identified. This technique allows the acquisition of fully quantitative data, not only for the larger inclusions within the ceramics but also for the typically finer-grained groundmass/matrix, whilst also providing the overall texture of the ceramic.     

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.     

Long-term clay raw material selection and use in the region of Classical/Hellenistic to Early Byzantine Sagalassos (SW Turkey)

A provenance study was carried out on coarse ceramics from the Classical/Hellenistic to Mid-Byzantine city of Sagalassos, SW Turkey. The ceramics were sampled from the excavations of the city, and clay raw materials were sampled throughout its ancient territory. Used techniques were optical microscopy and electron microprobe analysis on thin sections, geochemical analysis (fusion ICP/MS and mineralogical analysis (X-ray diffraction). The geochemical/mineralogical diversity in the ceramics is not as wide as for the clay raw materials. It seems that even at the restricted scale of this study, the resources were limited to the area around the ancient site. The differences between the ceramics are likely due to the use of different ophiolitic clay bodies being exploited for their production.     

An archaeometric study of the Konya basin metallic ware through FTIR and XRD analysis with chemometrics: Central Anatolian Early Bronze Age ceramics

Fourier-transform infrared, X-ray diffraction and chemometrics were used to characterize the mineralogical composition and firing conditions of 59 Early Bronze Age ceramic sherds from the Konya Plain (Turkey). These include the Konya Basin Metallic Ware (KBMW) and a control group of contemporary local products. The analysis indicates significant differences in mineral inclusions and firing temperatures, with KBMW generally being fired above 800°C and characterized by standardized fabric recipes. Assessed together with other published evidence, these results indicate a high degree of specialization in the production of KBMW ceramic assemblages in central Anatolia during the third millennium BCE.     

Roman double-layered crucibles from Autun/France: a petrological and geochemical approach

Eighteen double-layered crucible fragments found in an archaeological excavation site of the Lycée militaire (Autun/France), which dates to the Gallo-Roman period, were analysed with a series of classical mineralogical techniques in order to obtain knowledge about the raw materials of the individual layers. This work focuses on the usage of the crucibles as well as technical aspects of their production. The crucible fragments were studied by using petrographical (optical microscopy), elemental (SEM-EDS, EMPA, XRF-WDS) and mineralogical (XRD) techniques.     

Characterization of prehispanic cosmetics found in a burial of the ancient city of Teotihuacan (Mexico)

The present paper reports the chemical data obtained on samples of pigmenting materials contained in 31 miniature vessels found in a burial found in Teopancazco, a multiethnic neighborhood center located in the southeastern sector of the archaeological site of Teotihuacan (Central Mexico) and the analytical protocol established for the complete characterization of these archaeological materials. For this purpose a multi-technique approach based on the combination of several non destructive and micro-destructive instrumental techniques, namely, light microscopy (LM), scanning electron microscopy-X-ray microanalysis (SEM-EDX), transmission electron microscopy (TEM), voltammetry of microparticles (VMP), X-ray microdiffraction (μXRD), X-ray diffraction (XRD), UV-Vis spectrophotometry, FTIR spectroscopy and gas chromatography-mass spectrometry (GC-MS) has been developed in an attempt to completely characterize these materials. These instrumental techniques provide reliable and complementary data including elemental and mineralogical composition, identification of functional groups as well as speciation studies of electroactive species. Among the most relevant findings, volcanic pyroclastic rocks and clayey soils, most probably, from the Teotihuacan valley as well as galena, jarosite and mica from other provenances in Mesoamerica, have been identified. Charcoal and Ocote resin have also been identified. The chemical composition of the samples is discussed with a view to the possible function as cosmetic materials and their use in funerary rites. The results have been critically compared with those others obtained in other ancient civilizations. The study carried out on the materials found in the burial 105 is especially relevant insofar it represents the first evidence, scientifically characterized, of the use of cosmetics in Mesoamerica at this early period (AD 200-550).     

Archaeometric investigation of Roman tesserae from Herculaneum (Italy) by the combined use of complementary micro-destructive analytical techniques

Vitreous tesserae from two mosaics in Herculaneum (Italy) dating from the 1st century AD have been investigated in order to gather information on Imperial Age opaque glass. The combined use of complementary micro-destructive analytical techniques, namely optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), inductively coupled plasma-mass spectrometry (ICP-MS), transmission electron microscopy (TEM), and X-ray powder diffraction (XRPD) allowed to define the nature of formers, fluxes, chromophores and opacifying compounds and to determine the type of raw materials employed for their introduction. The results confirmed the high technological level of Imperial Age glassmakers and clarified some details of the production processes. Experimental data have been obtained concerning formation of antimony-based opacifiers. The presence of tin-containing Ca- and Pb-antimonates has been ascertained in various green, yellow and turquoise tesserae. Moreover, unusual divergences from the established Roman age ‘low magnesia–low potash’ (LMLK) glass composition have been found for some red and green samples.     

PETROGRAPHIC AND GEOCHEMICAL EVIDENCE FOR LONG‐STANDING SUPPLY OF RAW MATERIALS IN NEOLITHIC POTTERY (MENDANDIA SITE,SPAIN)

Pottery from the Neolithic Mendandia site has been studied. The radiocarbon dating of the site corresponds to a range of dates from 7488–7546 cal bc to 5283–5437 cal bc : the first occurrence of pottery is dated at 5968–6040 cal bc for the lower level III, and up to 5386–5560 cal bc for level II. The antiquity of the potsherds places them within the oldest pottery production sequences in the Iberian Peninsula, which adds to the interest of this study. Ten potsherds from level II and five from level III are analysed for their petrographic and chemical characterization. The petrographic data show two different methods of raw materials manufacture—intentionally tempered pottery (ITP), using calcite and/or limestone and grog, and naturally or non‐intentionally tempered pottery (NTP). According to the matrix paste features, on the basis of the amount, shape, and average or size range of the mineral inclusions, clayed (type A) and sandy (type B) paste types were established and related to two different source areas. The chemical features also indicate two raw material sources and are in agreement with the petrographic paste types. The absence of significant chemical and mineralogical differences between the pottery from levels II and III suggests two contrasting areas for raw materials supply that lasted for at least 600 years.     

Chemical and lead isotope analysis of some lead-barium glass wares from the Warring States Period,unearthed from Chu tombs in Changde City,Hunan Province,China

In the context of the present study, we have conducted chemical and lead isotope analyses on twelve ancient glass samples unearthed from Chu tombs in Changde City, Hunan Province. The results of the chemical analysis of these samples show that all samples are PbO–BaO–SiO₂ glasses, thus indicating that they are all traditional ancient Chinese glasses. The chemical results also suggest that all Bi wares may either share a common source or were produced according to similar recipes. In turn, the eye beads are different from the Bi wares for their distinct chemical composition. The chemical results indicate that silica, lead-bearing material, barium-bearing material, and sodium/lime-bearing material are the main independent components of the raw materials employed in the production of these glass wares.