POST‐MEDIEVAL CRUCIBLE PRODUCTION AND DISTRIBUTION: A STUDY OF MATERIALS AND MATERIALITIES*

This paper is concerned with the manufacture and trade of post‐medieval crucibles (14th–19th centuries). The analytical study of crucibles from different contexts in Europe and America employed optical microscopy and SEM–EDS, coupled with archaeological and historical data. We identified two major producers of crucibles, both of them in Central Europe, whose products appear widely distributed internationally. The analytical data allow an explanation of the technical reasons behind their superior reputation, as both crucible types shared comparable material properties, such as thermal, chemical and mechanical stability. Conversely, the two crucible types were radically different in their manufacture and appearance. We argue that, besides technical considerations, sensorial aspects such as texture and colour may have played an important role in the perception and choice of materials.     

PROVENIENCE STUDY OF MEDIEVAL BULGARIAN GLASSES BY NAA AND CLUSTER ANALYSIS

The neutron activation analysis results from 30 glass samples were subjected to cluster analysis. The reliable localization of part of the medieval glass finds from Preslav enabled the evaluation of the variety of the production of a medieval glass workshop (ninth-tenth century), allowing conclusions to be made about the technological level of glass-making in Bulgaria during the Middle Ages. The work proved that NAA followed by cluster analysis is a successful approach to finding the local and chronological features of the investigated glasses.     

A SCIENTIFIC STUDY OF TRADITIONAL KOREAN CELADONS AND THEIR MODERN DEVELOPMENTS

Eighty sherds from nine different kiln sites representing a wide geographic distribution and a long time span of Korean celadon culture are analysed for macroscopic and compositional characteristics. Additionally chemical and mineral compositions of six unglazed sherds are compared with those of some modern raw materials. Unusually high values of alumina in the earliest Kangjin pieces of the middle ninth and early tenth century (I¹) could represent a significant technological innovation at the end of this period at this most important celadon production centre. Similarity in chemical and mineral compositions between unglazed sherds and some raw materials such as Kangjin clay and pottery stone show the possibility that many of the celadons were made from these types of raw materials as found in nature without additives and only after mechanical refining.     

PROGRESS REVIEW OF THE SCIENTIFIC STUDY OF CHINESE ANCIENT JADE

The interdisciplinary study of cultural heritage has become a scholarly hotspot in archaeology. Ancient jade serves as an important symbol of Chinese traditional culture, so the study of it is a critical part of this trend. The past 30 years have witnessed great progress in research on ancient jade, with the involvement of basic theory and the technological application of many science subjects. This paper summarizes the research status, methodology and prospects in the research on raw material (jade texture), provenance and secondary change of Chinese ancient jade, in the hope of benefiting future studies of ancient jade.     

THE MAP IN THE SCIENTIFIC AND ADMINISTRATIVE ACTIVITIES OF N.I. VAVILOV

Special attention is devoted to Vavilov's use of detailed maps for (a) recording initial results of field work in the study of local agriculture and ranges of domesticated plants in travels across several continents; and (b) presenting information about a large number of processes and phenomena in a concise way, affording the basis for their critical analysis and comparison. He was involved in programs to map Soviet and world agriculture (translated by Jay K. Mitchell, PlanEcon, Inc., Washington, DC 20005).     

THE SCIENTIFIC ANALYSIS OF A GROUP OF ROMAN-AGE ENAMELLED BROOCHES

Results of analysis, mainly by X-ray fluorescence, are presented for a representative selection of enamelled brooches. The enamel composition is quite distinct, and shows considerable technical sophistication on the part of the manufacturers. The production of different colours and of opacity in the enamel is related to the chemical composition, and analyses of the metal substrate suggest that the alloy was carefully chosen. The implications of this investigation for the study of Roman enamelwork in general are discussed.     

AN ARCHAEOMETRIC STUDY OF MEDIEVAL GLASS FROM THE FIRST BULGARIAN CAPITAL,PLISKA (NINTH TO TENTH CENTURY AD)

Glass finds from the first Bulgarian capital, Pliska, have been analysed by instrumental neutron activation analysis. The analytical data, together with previous results from analysis of glass samples from the second Bulgarian capital, Preslav, were subjected to cluster and discriminant analysis. The local origin of part of the analysed samples was proven and some conclusions about the technology of production were possible.     

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.     

A GROUND RADAR SURVEY OF MEDIEVAL KILN SITES IN SUZU CITY,WESTERN JAPAN*

A ground-penetrating radar study of medieval kiln sites located near Suzu city, on the Noto peninsula, was conducted prior to excavation. Archaeological site plans estimated from time slices of the closely-spaced parallel radar profiles are compared with excavations and a proton magnetometer survey. The results indicate that non-destructive remote sensing with radar can help to determine effectively the presence and general structural features of intact kiln floors.     

SERIPHOS SURFACES: A STUDY OF COPPER SLAG HEAPS AND COPPER SOURCES IN THE CONTEXT OF EARLY BRONZE AGE AEGEAN METAL PRODUCTION

Kephala and Phournoi, on the island of Seriphos, add to a growing number of EBA metal production sites identified in the south‐central Aegean. Analytical examination of samples from the two sites addressed the technological parameters of the copper smelting process, indicating the use of mixed oxidic and sulphidic copper–iron ores to produce unalloyed copper with minute copper sulphide inclusions. A preliminary geological reconnaissance of the island identified several small copper mineralizations, one of them close to the site of Kephala. Nevertheless, the ore sources used remain unclear. Comparisons are made with other contemporaneous neighbouring smelting sites.