LUSTRE COLOUR AND SHINE FROM THE OLLERIES XIQUES WORKSHOP IN PATERNA (SPAIN), 13TH CENTURY AD: NANOSTRUCTURE,CHEMICAL COMPOSITION AND ANNEALING CONDITIONS*

Lustre is a medieval ceramic decoration, corresponding to a nanostructured thin layer formed by metallic copper and silver nanocrystals embedded in a glass matrix, which required deep knowledge on the part of the artisans with regard to the raw materials used and the kiln conditions. Their empirical knowledge led to the achievement of colourful lustre decorations ranging from reddish to yellowish or even greenish, some of them with a metallic shine with an associated purplish iridescence. Lustre ceramics dating from the 13th century from the Olleries Xiques workshop in Paterna (Spain) have been studied, linking their chemical composition and nanostructure with their colours and shine. Two kinds of nanostructures are found, yellowish lustre decoration constituted by a silver metal–glass nanocomposite, and reddish lustre decoration constituted by metallic copper nanocrystals and copper oxide nanocrystals; in some cases, metallic copper nanocrystals covered with an oxidized shell of CuO and partly Cu₂O have been found. However, even with significant amounts of copper oxide, the lustre still exhibits a copper metal‐like shine. The bluish iridescence observed at a specular angle in the lustre could not be explained completely by means of the chemical composition, and metallic silver nanoparticle light scattering is proposed as a possible explanation.     

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.     

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.     

Another (mud)brick in the wall: scientific analysis of Bronze Age earthen construction materials from East Crete

Mudbricks appear to have been one of the most common building materials used in domestic architecture in Bronze Age Crete. Well-preserved earthen construction materials from the sites of Vasiliki, Makrygialos and Mochlos in East Crete have been examined with regard to their macromorphological characteristics and their mineralogical and chemical composition in order to investigate the nature of the raw materials used, the technology of manufacture and the potential use of specific recipes. The methods applied include a combination of mineralogical and chemical analytical techniques, namely petrography, neutron activation (NAA), X-ray fluorescence (XRF), and X-ray diffraction (XRD) analysis. Finally, a range of raw materials from the immediate vicinity of each site were sampled and analyzed in order to compare with the archaeological data and identify potential sources. The analyses suggested that there is a degree of standardization in the recipes and the manufacturing process and that the selection of the raw materials depends on availability.     

Vietnamese (15th Century) Blue‐And‐White,Tam Thai and Lustre Porcelains/Stonewares: Glaze Composition and Decoration Techniques*

EDS, X‐ray fluorescence, Raman spectroscopy, thermal expansion–shrinkage measurement and scanning electron microscopy were applied to determine the elemental components, structural phases and glazing temperatures of the transparent glazes, blue underglaze and overglaze tam thai (including gold‐like lustre) decorations from the 15th‐century Vietnamese porcelains/stonewares found at the Chu Ðâu–My Xa kiln site and in the Cù Lao Chàm (Hôi An) cargo. The ancient technology for colouring the glazes is discussed. The various blue tones in the underglazed décor result from cobalt‐containing manganese ore, with the intentional addition of iron oxide. The overglaze copper‐green and the gold‐like lustre were obtained by dispersing copper in lead‐based glass. The red colour was made using hematite dispersed in lead‐rich flux.     

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.     

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.     

Composition of the Lustre Pigment Used in the Production Of 13th Century AD Raqqa Lustreware from Syria

The very rare find of the relic of the original lustre pigment attached to the glazed surface of a sherd of 13th century ad Raqqa type lustreware from Syria has been analysed using a combination of analytical scanning electron microscopy (SEM), micro‐X‐ray diffraction (XRD) and Rutherford backscattering spectroscopy (RBS). The composition of the pigment relic inferred from these analyses is shown to match those of recipes for lustre production given in the early treatises by Jazbir Ibn Hayyan (c. ad 721–c. ad 815) and Abū'l Qasim (ad 1301). Similarities and differences between this 13th century ad Syrian pigment and pigments used in the ninth century ad in Iraq, in the 14th century ad in Islamic and Hispano‐Moresque Spain, and in the 16th century ad in Renaissance Italy are discussed.     

Ceramic Ethnoarchaeometry in Western Sardinia: Production of Cooking Ware at Pabillonis

Ceramic ethnoarchaeology has been used to explore fully the chaîne opératoire and to understand all of the stages and factors involved in pottery production, such as raw material selection or paste recipes used by the potters. This work presents the results of the application of compositional analysis undertaken in the village of Pabillonis (western Sardinia, Italy), the main cooking ware production centre of the island. Pottery and local clays have been characterized using a combination of analytical techniques. By integrating the ethnographic information and the archaeometric approach, it was possible to reconstruct the operational sequence, exploring the relationship between the processing of raw materials and the functionality of the final products, and the intra‐production compositional variability.     

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.     

Exploring Bristol’s historic glass industry: archaeological investigation at the Soap Boilers’ and Hoopers’ glasshouses,and the Powell & Ricketts’ Bottle Works,Avon Street,Glass Wharf,Bristol

SUMMARY: In 2007, extensive archaeological excavation was undertaken on an important post-medieval glassworking site at Glass Wharf, Bristol. The excavation exposed remains relating to a series of glassworks dating between the early 18th and early 20th centuries and, significantly, uncovered a sequence of five glass-melting furnaces and covering structures, which together reflect wider changes in glassmaking technology throughout these periods. Detailed scientific analysis of glassworking debris from the excavation has also been undertaken, which provides much-needed detail on the development of recipes and raw materials used in bottle manufacture during the 18th and 19th centuries.     

Technological Choices in Hand‐Made Indigenous Pottery from Western Mallorca (Balearic Islands,Spain) (C.1200–75 bc): An Archaeometric Approach

This paper addresses the technological choices observed in Mallorca (Spain) for the production of hand‐made pottery during the Late Bronze and Iron Age. We have conducted a diachronic analysis of the ceramic assemblages recovered from two archaeological sites placed in the same territory by means of X‐ray fluorescence and optical microscopy by thin‐section analysis. The archaeometric characterization of the hand‐made vessels allows us to establish several compositional groups related to the use of different raw materials and certain paste recipes associated with the archaeological sites and periods considered. Thus, this study evidences different productive strategies in each site and across time in the same geographical area.     

Two unique Byzantine immured lead-glazed relief ceramic icons and related tiles from the church of St Basil in Arta,Greece: investigation and interpretation of materials and techniques

St Basil’s late Byzantine church in Arta (NW Greece) is unique among other surviving churches of the same era as a result of two glazed relief ceramic icons and arrays of square glazed tiles that decorate its external wall. The latter decorative items were carefully examined by means of analytical techniques in order to reveal the materials and techniques used for their manufacture and thus interpret their connection to the contemporary Byzantine and Italian ceramics. Analytical results indicate that lead plus quartz suspensions were employed for the fabrication of the majority of the glazes in the spirit of recipes for Italian Archaic majolica pottery, and thus they are differentiated from the common contemporary Byzantine products. Nonetheless, the raw materials used in the Arta area ceramics deviate substantially from those used in the Italian products and, possibly, a local (NW Greece) production is reflected. The unexpected rather rich variety of raw materials and/or techniques that underlies the visual uniformity of the glazed material in consideration might reflect selection of the best products generated upon experimentation with various contemporary technical alternatives. Finally, the decorative arrangement of the glazed items that we see today might reflect a way to circumventing original objections to the ceramic icon innovation.     

LUSTRE-DECORATED CERAMICS FROM A 15TH TO 16TH CENTURY PRODUCTION IN SEVILLE*

A set of 17 fragments of ceramics have been uncovered on the occasion of excavations of a workshop in Triana near Seville. These ceramics are typical of objects that are not commonly encountered in present collections in spite of intensive production during the 15th–16th centuries. Chemical and mineralogical analyses have been performed using various techniques (X-ray fluorescence and diffraction, SEM, ion beam analyses). The majority of the ceramic sherds represent the diversity of the Seville production; three fragments recovered in the same archaeological context were not locally produced and belong to the production of eastern Spain (Valence area). The ceramic bodies of the Seville sherds are compatible with the use of clays from the Guadalquivir valley. The glaze and the lustre decoration are comparable to those produced in eastern Spain. These conclusions are based on data that represent the production of a single workshop in Seville; the scatter of the data is due to variations in the processing and/or to alterations during the five centuries of burial of the ceramic fragments.     

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.     

Pottery Production in the Buddhist Communities in Central Asia: The Kushan‐Sassanian Pottery Workshop of Kara Tepe (Termez,Uzbekistan)

We present the first full archaeometrical study of Kushan‐Sassanian pottery from the Buddhist monastic complexes at Kara Tepe (Termez, Uzbekistan), recovered both in the pottery workshop and in the monastery, using a combination of analytical methods (XRF, XRD, SEM–EDS and OM). The study allowed the identification of the reference group, the correspondent fabric, the raw materials used for its productions, some of the technological processes involved in manufacture and several weathering processes. All the results confirm that the kiln was supplying the religious community of the monastery with pottery, made using local raw materials, and highlight the possibility that the kiln could have supplied the nearby monastic complexes, where no kilns have been found. Further archaeological evidence indicates the existence of specialized potters working itinerantly at the broader Bactrian area.     

ELECTRON BACKSCATTER DIFFRACTION (EBSD): A NEW TECHNIQUE FOR THE IDENTIFICATION OF PIGMENTS AND RAW MATERIALS IN HISTORIC GLASSES AND CERAMICS

Coloured samples of glass and ceramic were selected for EBSD investigation to verify the potential (advantages and limitations) of this technique in the characterization of the raw materials used and the neoformation phases originating from the manufacturing processes. In the case of copper‐bearing red glasses, it was verified that micrometric droplets, residuals of the original copper source, can be ascribed to metallic copper or to a low‐Sn bronze, due to strongly similar lattice parameters. From the same samples, micrometric flakes were identified by EBSD as magnetite and interpreted as residues of the reducing agent used in the production of such red glasses. Further, the technique allowed the pigment responsible for the yellow colouring of some incised slipware to be recognized as bindheimite. In a third case, the black pigment, contained in some Nestorian decorated pottery, was identified as an amorphous phase of Mn oxide. The accurate identification of the colouring particles and other products or materials offered a more precise comprehension of the production technique, period and site of the examined artefacts, together with scientific parameters for the identification of the raw materials, their transformation during the production cycle and an evaluation of the most reliable recipes used for their preparation.     

Pottery production on Rishiri Island,Japan: perspectives from X‐ray fluorescence studies

Energy‐dispersive X‐ray fluorescence (EDXRF) was used to determine the minor and trace element composition of 54 sherds of pottery dating from the Final Jomon to Okhotsk periods. The majority of the sherds came from Rishiri Island, Japan. Principal component (PC) scores were calculated using the log transformed concentration values, and groups were sought in the PC scores using kernel density estimates (KDEs). Two main groups were found in the data; linear and quadratic discriminant analysis classified both groups successfully. Significant differences in the concentrations of Cu, Fe, K, Nb, Pb, Rb, Th and Zr were found to exist between the two groups. The lack of correspondence between chronological ware types and geochemical groups implies that the same raw materials and paste recipes were in use during the Epi‐Jomon and Okhotsk eras on Rishiri Island. One possiblity is that the Epi‐Jomon and Okhotsk potters used the same clays and tempers, since no other alternatives were available. Alternatively, the Okhotsk potters could have adopted the same paste recipes as the Epi‐Jomon potters, or the Okhotsk pottery tradition could be descended from the Epi‐Jomon pottery tradition.     

Architectural decorations from the private buildings in the Market Square at Tamn

The architectural decorations in pre-Islamic Yemen feature a wide and heterogeneous range of materials. Their many functions cover different fields: domestic, religious, funeral architecture, grave goods (particularly censers and furnishings) and, last but not least, epigraphs. Thus the study of this class of materials requires a two-fold approach: on the one hand to identify and understand the various ornamental motifs in themselves; on the other to study which types of decorative motifs were applied in various circumstances, and hence what it is that links them to each other and to the structure they adorn. This work aims to provide a foundation for a thorough study of the decorative motifs on stonework in various contexts. We begin by defining the use of architectural decorations in the domestic sphere. The archaeological context of the Market Square at Tamna' is particularly suitable, in view of the number of houses brought to light, the amount of related materials found and, above all, because it represents a coherent urban context over a specific period of time.     

Early Islamic lustre from Egypt,Syria and Iran (10th to 13th century AD)

This paper presents a study of a representative selection of lustre ceramics dating from the last quarter of the 10th century AD to the second half of the 13th century AD from Egypt, Syria and Iran. The study concentrates on the structure and chemistry of the lustre itself over the historical period considered and has found a number of significant similarities between the production centres studied. Previous work on the reproduction of lustre under laboratory-controlled conditions allows the archaeological data to be related to the historical technological aspects of lustre production. The results obtained, although restricted to the limited number of samples studied, have demonstrated the occurrence of significant differences and similarities between lustre productions during this period. The possible reasons for these changes are discussed.