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.     

An archaeometric contribution to the characterization of Renaissance maiolica from Urbino and a comparison with coeval maiolica from Pesaro (the Marches,central Italy)

The results of an archaeometric trial study performed on an important finding of Renaissance maiolica (mid‐15th to early 16th century) from the Ducal Palace of Urbino are presented. Mineralogical–petrographic data (XRD, OP, SEM–EDS) and chemical characterization (ICP/AES–MS: major and trace elements) of both ceramic bodies and glazes were compared with similar data provided on coeval maiolica found in archaeological excavations in Pesaro, now stored in the city's Municipal Museum, in order to verify an origin of the potteries from common (Pesaro) or different (Pesaro and Urbino) production centres. The results indicate that ceramic bodies were produced with quite similar illitic–calcareous clays, most probably taken from the same local Pliocene Formation. Similarities were also found concerning the glaze's glass (silica–lead), colourants (cobalt, copper and manganese) and pigments (lead antimonate and cassiterite).     

GLAZED CERAMIC MANUFACTURING IN SOUTHERN TUSCANY (ITALY): EVIDENCE OF TECHNOLOGICAL CONTINUITY THROUGHOUT THE MEDIEVAL PERIOD (10TH–14TH CENTURIES)*

Archaeometric investigation allowed the characterization of two important classes of ceramics: ‘vetrina sparsa’ and ‘invetriata grezza’. Their archaeological peculiarity makes them particularly suited for tracing the evolution of glaze manufacturing in southern Tuscany throughout the medieval period (10th–14th centuries). These ceramics were found in different sites of historical importance, and also from a mining perspective. Local copper, lead, zinc and iron mineralizations supported the growth of several settlements in the vicinity of the mines. The many castles and different archaeological finds (ceramics, glazed ceramic, slag etc.) attest to the intense mineral exploitation of the area from at least the first millennium bc up to the modern period. In light of these geological and archaeological characteristics, archaeometric investigation was intended to provide insight into ancient technical knowledge of ceramic glazing and to determine the source area for raw materials in the medieval period (10th–14th centuries). Ceramic bodies were analysed through OM, XRDp, SEM–EDS and XRF, while coatings were investigated through SEM–EDS. Mineralogical, petrographic and chemical analyses revealed slightly different preparation and firing processes for the two classes of ceramics. These data suggest the continuity through the centuries of the ‘vetrina sparsa’ and ‘invetriata grezza’ production technology. The mineralogical phases, such as monazite, xenotime, zircon, barite, Ti oxide, ilmenite, titanite, tourmaline and ilvaite, and the lithic (intrusive and volcanic) fragments detected within the ceramic bodies suggest a source area in the vicinity of the Campiglia mining district. Lastly, the presence of Cu–Zn–Pb (Ag) and Fe sulphide mineralizations (materials used to produce glaze) in the area supports the hypothesis of local manufacture.     

A STUDY ON LATE MEDIEVAL TRANSPARENT‐GLAZED POTTERY AND ARCHAIC MAJOLICA FROM ORVIETO (CENTRAL ITALY)*

Nineteen samples of medieval transparent‐glazed pottery and archaic majolica from Orvieto (central Italy) were studied. They were classified by archaeological criterion as follows: five transparent‐glazed fragments with green and brown decorations (first half of the 13th century), eight green transparent‐glazed fragments (13th century) and six tin‐glazed fragments with green and brown decorations (second half of the 13th century). SEM–EDX, XRD (the Rietveld method) and XRF were used to characterize the chemical and mineralogical compositions both of the bodies and the coatings. In all of the samples, the paste is Ca‐rich with CaO contents as high as 13–20 wt%. The mineralogical composition is compatible with a firing temperature of about 950°C, which is the typical temperature reached in a wood kiln. No difference was observed between the bodies of transparent‐ and tin‐glazed pottery. In the case of transparent glazes, the burial conditions lead to heavy weathering of the samples. However, on the basis of the analyses carried out in non‐weathered areas, the typical composition is PbO 55–65 wt%, SiO₂31–35 wt%. In tin glazes, the tin is scattered on the mass of the glaze as SnO₂crystals with a concentration of 7–14 wt%. Concerning the decorations, it is established that the green colour is due to the presence of copper, while manganese is responsible for the brown colour. These pigments, which represent the typical colours of ‘archaic majolica’, are spread through the glaze homogeneously, apart from one case in which there is clear evidence of manganese oxide crystals.     

The Archaeometric Characterization of Majolica Ceramics from Talavera de la Reina and El Puente del Arzobispo (Toledo,Spain)

In this study, an archaeometric characterization of 32 ceramic fragments from Talavera de la Reina and El Puente del Arzobispo, dated between the 16th and 18th centuries, has been carried out. Together with three fragments of biscuit, they have been analysed through X‐ray diffraction (XRD), X‐ray fluorescence (XRF), differential scanning calorimetry and thermogravimetric analysis (DSC–TGA). From these chemical results, a statistical study using exclusively majolica ceramics has been carried out. This work has allowed us to find certain differences between the manufactures of the two production centres on the basis of their chemical composition. The mineralogical study has allowed us to determine the estimated firing temperatures of each sample, using the estimated firing temperature (EFT) as an argument for their classification into three fabrics.     

PRODUCTION TECHNOLOGY OF ROMAN LEAD‐GLAZED POTTERY AND ITS CONTINUANCE INTO LATE ANTIQUITY

A broad selection of Roman lead‐glazed pottery dating from the first century ad through the fifth century ad was studied to establish locations of workshops and to address their technology of production. The ceramic bodies were analysed by ICP–AES. In addition, lead isotope analysis was undertaken on a selection of glazes. These findings suggested that there were several regions responsible for the production of lead‐glazed ceramics in the western Roman world, including central Gaul, Italy and, probably, Serbia and Romania. Using the body compositions as a starting point, the glazing techniques employed by each of the potential workshops were examined using electron probe microanalysis. It was determined that there were two primary methods of glazing. The first method used lead oxide by itself applied to non‐calcareous clay bodies, and the second method used a lead oxide‐plus‐quartz mixture applied to calcareous clay bodies. Based on these data for clay composition and glazing method, transfer of technology from the Hellenistic east to the western Roman world was proposed. Likewise, the inheritance of lead‐glazing technology into late antiquity was established by making comparisons to lead‐glazed ceramics dating to the seventh to ninth centuries from Italy, the Byzantine world and Tang Dynasty China.     

CHEMICAL AND MINERALOGICAL APPROACHES TO THE ORGANIZATION OF LATE BRONZE AGE NUZI WARE PRODUCTION

In order to investigate the nature and organization of high‐status ceramic production in the Late Bronze Age, samples of Nuzi Ware from four different sites were analysed using scanning electron microscopy (SEM–EDS) and inductively coupled plasma atomic emission spectroscopy (ICP–AES). Chemical and mineralogical evidence suggests that Nuzi Ware was produced in at least two distinct regions, one probably in the Adhaim Basin in northern Iraq and another possibly in the Orontes catchment in southeastern Turkey. The existence of individual production units probably developed in response to the local elites' desire to imitate the tastes of the Mitanni aristocracy, resulting in a mapping of political relationships on to material culture.     

DEEPLY COLOURED AND BLACK GLASS IN THE NORTHERN PROVINCES OF THE ROMAN EMPIRE: DIFFERENCES AND SIMILARITIES IN CHEMICAL COMPOSITION BEFORE AND AFTER ad 150*

In this work we attempt to elucidate the chronological and geographical origin of deeply coloured and black glass dating between 100 bc and ad 300 on the basis of their major and trace element compositions. Samples from the western and eastern parts of the Roman Empire were analysed. Analytical data were obtained by means of a scanning electron microscope – energy‐dispersive system (SEM–EDS, 63 samples analysed) and laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS, 41 samples analysed). Among the glass fragments analysed, dark brown, dark purple and dark green hues could be distinguished. Only among the dark green fragments could a clear compositional distinction be observed between fragments dated to the periods before and after ad 150. In the early samples (first century bc to first century ad ), iron, responsible for the green hue, was introduced by using impure sand containing relatively high amounts of Ti. In contrast, a Ti‐poor source of iron was employed, containing Sb, Co and Pb in trace quantities, in order to obtain the dark green colour in the later glass samples. The analytical results obtained by combining SEM–EDS and LA–ICP–MS are therefore consistent with a differentiation of glassmaking recipes, detectable in glass composition, occurring in the period around ad 150.     

A MICRO‐RAMAN AND INTERNAL MICROSTRATIGRAPHIC STUDY OF CERAMIC SHERDS FROM THE KILNS OF THE MEDICI CASTLE AT CAFAGGIOLO*

Nine representative sherds from the old (14th–16th century) kilns at the Castle of Cafaggiolo in Tuscany have been analysed by means of internal microstratigraphic analyses and micro‐Raman spectroscopy and classified as follows: six engobed and glazed fragments, of which three are covered with an opaque white, decorated layer, one is marbleized, and two are engobed. The surface of the two engobed sherds, fragments of unfinished products, indicates that at least two firing processes were used. Two samples show characteristics of Byzantine pottery, and three of them can be classified as Islamic ware or maiolica, whilst the other one displays intermediate characteristics. The variety of ceramic wares indicates the presence of craftsmen with differing expertise, and suggests that part of their work was dedicated to experimentation on new ceramic production techniques.     

ARCHAEOMETRIC ANALYSES ON ‘CORINTHIAN B’ TRANSPORT AMPHORAE FOUND AT GELA (SICILY,ITALY)*

The aim of this work is to throw light on the archaic production of ‘Corinthian B’ amphorae, which are widely diffused in the Western Mediterranean basin and are also present in Greece, but whose geographical provenance is still under discussion. We analysed a group of 37 samples belonging to different ceramic classes dated to the sixth and fifth centuries bc . In particular, there were 19 sherds of trade amphorae of the so‐called archaic ‘Corinthian B’ type, from archaeological excavations in Gela (Sicily, Italy). As a comparison, we also investigated 18 samples of tiles and local coarse pottery from Sibari (Calabria, Italy). The samples were analysed using different techniques, such as optical analysis with a polarized‐light microscope (OM), X‐ray diffraction (XRD), Fourier transform–infrared absorption (FT–IR) and inductively coupled plasma–optical emission spectroscopy (ICP–OES). The combination of these complementary analytical methods allowed us to characterize the samples, determine their firing temperatures and identify the probable provenance. The study of thin sections of sherds by OM allowed us to divide the investigated amphorae into two main groups: the first was characterized by a composition that suggested a Western provenance, in particular from the Calabrian–Peloritan region; the second one was very similar to the ‘Corinthian B’ amphorae that come from Corinth and have been classified as ‘fabric class 1’ by Whitbread (1995 ). The XRD and FT–IR results permitted us to determine the mineral composition of the findings and to estimate their firing temperature. The ICP–OES technique was particularly useful in identifying the production centres. In fact, in the studied pottery, this analysis revealed Ni and Cr values that were noticeably different between Greek and southern Italian production.     

ANTIMONATE OPAQUE GLAZE COLOURS FROM THE FAIENCE MANUFACTURE OF LE BOIS D’ÉPENSE (19TH CENTURY,NORTHEASTERN FRANCE)*

Three types of antimony‐based, opaque ceramic colours were used in the faience workshop of Le Bois d’Épense during the first decades of the 19th century; that is, yellow, tawny and green. Yellow is generated by lead antimonate crystals (Naples Yellow), which are incorporated into an uncoloured glass matrix. According to SEM–EDS measurements, these pigments contain iron. The tawny colour is the optical result of the combined presence of similar yellow, iron‐bearing lead antimonate particles in a Fe‐rich, brownish glass matrix. The green opaque colour is produced by the combination of a blue cobalt glass and yellow Pb–Sn–Fe‐antimonate crystals. Cores of zoned pigments lighten the recipes, according to which the pigments were produced. First, they were synthesized by calcination, ground and then mixed with a colourless, brown or blue glass powder. The resulting powder mixture was added to a liquid agent and used as high‐temperature ceramic colour.     

CHARACTERIZATION OF 18TH‐CENTURY MEISSEN PORCELAIN USING SEM–EDS*

Analytical investigations of fragmented Meissen porcelains well dated to between 1725 and 1763 have been carried out using SEM–EDS. The aim of the analysis was to characterize elements in bodies, glazes and overglaze enamels in order to create a baseline data set of materials used in the manufacture of porcelain at the Meissen factory, Saxony, during the 18th century. Analyses indicate body and glaze compositions to be consistent with a post c.1720–30 date, when a change from a lime‐rich flux to a potassium‐rich flux is documented to have occurred. Overglaze enamel compositions are shown to be consistent with contemporary accounts of enamel preparations at Meissen. Overglaze enamel compositions show that mixtures of pigments, in addition to documented enamel 18th‐century preparations, were in use at Meissen between c. 1725 and 1763.     

French Decorative Ceramics Mass‐Produced During and After the 17th Century: Chemical Analyses of the Glazes

Chemical analyses of a group of Pb silicate–glazed decorative objets d'art showing scenes of the French royal family (Louis XIII and Henri IV), and biblical and classical figures, have been analysed and compared with other similar heritage ceramics and with the rustiques figulines of Bernard Palissy (1510–90) and his followers and imitators. In particular, non‐destructive ion‐beam chemical analyses (PIXE and PIGE) have been performed on 11 ceramic artefacts from the Cleveland Museum of Art (CMA) and a like number from several French museums; results for 13 objects are described in detail in this paper. SEM–EDX has been performed on chips (‘microsamples’) taken from small unobtrusive defective regions on the CMA ceramics. The results of the ion‐beam and SEM–EDX techniques are in good agreement. All the decorative ceramics included uniform non‐opacified glazes. None of these objects can be of 16th century production; all must date from the 17th to the 19th centuries.     

THE EVOLUTION OF LUSTRE CERAMICS FROM MANISES (VALENCIA,SPAIN) BETWEEN THE 14TH AND 18TH CENTURIES

A set of 33 fragments of lustre‐decorated ceramics uncovered during an archaeological excavation in Manises (Valencia, Spain) have been studied. These ceramics were produced in Manises from the 14th to the 18th century. This well‐dated set of ceramic shards represents the diversity of Manises lustre production and is a complete time sequence of reference for the technological analysis. Texture analysis of the glazes has been carried out by SEM–EDAX, the inner and outer surfaces of the lustre decorations being analysed with non‐destructive ion beams by PIXE and RBS, and also by high‐resolution electron microscopy. The results are compared with other lustre productions and the time trend of the microstructures, glaze and lustre composition is analysed. It is concluded that Sn was used to opacify glazes until the beginning of the 17th century and that changes in the lustre microstructure occurred around ad 1500.     

TECHNOLOGY OF PRODUCTION OF GHAZNAVID GLAZED POTTERY FROM BUST AND LASHKAR‐I BAZAR (AFGHANISTAN)

Fifteen fragments of glazed pottery were studied by scanning electron microscopy coupled with energy‐dispersive X‐ray analysis (SEM–EDS). The fragments, dated from between the 11th and the 12th centuries, are part of a group excavated at ancient Bust and Lashkar‐i Bazar (southern Afghanistan) and belonging to the International Museum of Ceramics in Faenza. All the samples are characterized by highly calcareous bodies, and all of them but one is coated with a transparent lead glaze; the last fragment is, instead, coated with a turquoise opaque lead–alkali glaze. With three exceptions, the studied fragments show underglaze decorations featuring white, red, green or black motifs applied on to a white, red or black engobe; one of the remaining glazes is applied on to a monochrome white slip and the other two directly on to the ceramic body. Optical microscopy and SEM images show that engobes and decorations were obtained by deposition of differently coloured clayey slips, the composition of which was characterized by EDS analyses. In particular, black engobes and decorative motifs were obtained by recourse to manganese and iron compounds or to chromium, magnesium and iron compounds; it appears that both possibilities could be exploited for obtaining different decorative motifs on the same object.     

THE PROVENANCE OF OBSIDIAN ARTEFACTS FROM THE WĀDĪ ATH‐THAYYILAH 3 NEOLITHIC SITE (EASTERN YEMEN PLATEAU) BY LA–ICP–MS

The geological sources of obsidian in the Red Sea region provide the raw material used for the production of obsidian artefacts found in prehistoric sites on both sides of the Red Sea, as far afield as Egypt, the Persian Gulf and Mesopotamia. This paper presents the chemical characterization of five obsidian geological samples and 20 prehistoric artefacts from a systematically excavated Neolithic settlement in highland Yemen. The major element concentrations were determined by SEM–EDS analysis and the trace element concentrations were analysed by the LA–ICP–MS method, an almost non‐destructive technique capable of chemically characterizing the volcanic glass. A comparison of archaeological and geological determinations allows the provenance of the obsidian used for the Neolithic artefacts to be traced to definite sources in the volcanic district of the central Yemen Plateau.     

A TECHNOLOGICAL EXAMINATION OF NINTH–TENTH CENTURY AD ABBASID BLUE‐AND‐WHITE WARE FROM IRAQ,AND ITS COMPARISON WITH EIGHTH CENTURY AD CHINESE BLUE‐AND‐WHITE SANCAI WARE*

Eight sherds of ninth–tenth century ad Abbaesid blue‐and‐white glazed earthenware, excavated in 1931 at Hira in western Iraq, were analysed using, variously, quantitative wavelength‐dispersive spectrometry (WDS) and energy‐dispersive spectrometry (EDS) in association with scanning electron microscopes (SEM), and semi‐quantitative X‐ray fluorescence spectrometry (XRF). In order to compare the compositions of the cobalt pigments used, the glazes of seven complete vessels of eighth century ad Chinese Tang blue‐and‐white sancai were also analysed semi‐quantitatively using XRF. The Abbasid wares were shown to have used traditional Mesopotamian alkali–lime glazes applied to calcareous clay bodies. Half the glazes examined were opacified with tin oxide. Three types of blue decoration (i.e., raised; spreading; and flat, non‐spreading) were produced using a variety of formulations, including a mixture of cobalt pigment with lead oxide. The sources of the ores used for the cobalt pigments have not been identified. However, the analytical data showed that the cobalt ore used for the Abbasid blue‐and‐white ware could be distinguished from that used for the Tang blue‐and‐white sancai by its higher iron content and by the presence of a significant amount of zinc. The use of cobalt‐blue decoration on the ninth–tenth century ad Abbasid ware was anticipated in China by eighth century ad Tang blue‐and‐white sancai wares. However, whether its introduction by the Abbasid potters should be seen as an independent invention that followed the introduction of tin‐opacified glazes in Iraq, or whether it was influenced in some way by Chinese originals, is still unresolved.     

CUERDA SECA CERAMICS FROM AL‐ANDALUS,ISLAMIC SPAIN AND PORTUGAL (10TH−12TH CENTURIES AD): INVESTIGATION WITH SEM–EDX AND CATHODOLUMINESCENCE*

Since little is known about the cuerda seca technique, our aim has been to complete an initial analysis of 11th‐century cuerda seca by studying fragments from the 10th century (Pechina, Almería) and the 12th century (Mértola and Almería), so as to establish the diachronic evolution of this technique. Characteristics specific to cuerda seca ceramic glazes were investigated using scanning electron microscopy (SEM) and quantitative chemical analysis with energy‐dispersive X‐ray spectrometry (EDX). The chemical compositions of the different‐coloured glazes (green, black, yellow and white) have given us valuable indications about the evolution of the technique. The opacification mode and the firing process were also investigated. With the help of cathodoluminescence (CL) and the study of modern ‘cuerda seca’ glazed ceramics, new hypotheses regarding the number of firing stages, taking into account glaze and paste transformations and their interactions, are put forward.     

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.     

LA–ICP–MS,SEM–EDS AND EPMA ANALYSIS OF EASTERN NORTH AMERICAN COPPER‐BASED ARTEFACTS: IMPACT OF CORROSION AND HETEROGENEITY ON THE RELIABILITY OF THE LA–ICP–MS COMPOSITIONAL RESULTS*

This study discusses the relevance of compositions obtained using laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) for the purpose of identifying the provenance of copper‐based artefacts found in Virginia at Native American sites dated from the 16th to the 18th centuries. Ten artefacts were investigated by scanning electron microscopy – energy dispersive spectrometry (SEM–EDS) to visualize the corrosion and characterize the heterogeneities in the metal and electron probe micro‐analysis (EPMA) to determine separately the compositions of the intact metal and of the corrosion product. It is shown that the corroded surfaces are highly depleted in zinc but that representative concentrations can be determined by sampling the deeper, uncorroded metal. In contrast, lead values are highly variable because of the heterogeneous distribution of this metal within the bulk copper. Despite these problems, brass is easily identifiable and American native copper and European smelted copper can be unambiguously distinguished with LA–ICP–MS on unprepared artefacts using As, Ag, Ni and Sb trace elements.