The corrosion protective effect of the surface modification of corrosion sensitive glass surfaces and of ORMOCER (= organically modified ceramic) coatings is investigated. The surface modification provides a modest protection, perhaps useful for additional protection in combination with external glazing. The advantage is the “invisability” of the modification due to the thickness of several molecular layers. An effective protection can be obtained by a diffusion barrier pigmented ORMOCER coatings. First outdoor results on medieval glasses are very hopeful, but long period experience is necessary for wider application.

Glass sensors, based on K-Ca-silicate glass chips, with a low durability against corrosive stresses, offer a new method for assessing the complex environmental stress situation of monuments and pieces of art. The easy-tohandle technique is able to detect the combined impact of climatic stresses, pollution and microbiological effects as well as synergetic interactions.

The chemical composition of the sensitive glasses enables judgements within few months. This way long-term estimates can be obtained without costly long-term investigations.

The corrosion progress is determined by microscopy and IR-spectroscopy of the weathered glass sensor surfaces. The sensors are already operating in the field of stained glass window preservation. They monitor the efficiency of different kinds of external protective glazings and the remaining stresses from the in-door environment of cathedrals.

The present study is directed to summarize several studies carried out in the recent past on stone decay processes taking place in the lagoon environment of Venice. The behaviour of the main types of stones used in Venetian buildings has been considered.

Istrian stone, Verona red stone and Carrara marble were studied.

The knowledge of the porosity and of the pore size distribution can contribute to clarify the physical transformation of decayed materials.

The research determined the morphology of stone decay processes for the different types of stone.

As far as the morphology of deterioration is concerned, there are two main types of decay which depend on the intrinsic properties of the stone: chemical-mineralogical composition and texture-structure.

Contour scaling is often observed on building facades, especially built from clay-rich sandstones. The paper shows that a soluble salt enriched zone and a decrease of the flexural strength below the stone surface can be detected even if a damage is not yet visible. A computer simulated wetting-drying process demonstrates that the mean humidity maximum is situated below the surface. Its depth coincides with the depth of the salt maximum and strenth minimum.

A non-destructive ultrasonic procedure has been developed for evaluating in-situ the relative deterioration of monumental stones. Ultrasonic waves are injected into the rock and they are registered, processed and petrophysically interpreted after travelling through it. The procedure applied to a Spanish Monastery (San Lorenzo de El Escorial, Madrid) built with a granitic rock is described.

The following methodology was applied: in-situ categorization of the observable deterioration forms, sampling in the original quarries, laboratory ageing tests and continuous ultrasonic monitoring, in-situ data acquisition, evaluation of the ultrasonic parameters by signal processing and stepwise discriminant analysis. All that information is petrophysically interpreted for an appropriate assignation of the in-situ studied masonry blocks to the categorized deterioration degrees.

Final in-situ results from the Monastery of El Escorial are here presented. Among the studied ultrasonic parameters energy is the most useful of all of them and velocity the least.

The crystallization of salts in building stones is one of the most common and severe deteriorating phenomencndeveloped on Historic Buildings. To evaluate their mechanical effects in treated and non-treated stones, experimental salt crystallization tests and the monitoring of the corresponding acoustic emission / microseismic activity, AE/MS, have been planned.

Salt crystallization tests have therefore been performed on a high porosity (30%) limestone used in the building of the Cathedral of Murcia (Spain). Each test consisted of 11 and 20 cycles (for the non-treated and treated specimens, respectively) of immersion of specimens in salt solution (14% Na2SO4. 10H2O) for 4 h., drying in an oven at 60 °C for 14 h. and final cooling at room temperature for 6 h. The treated specimens were consolidated by total immersion in ethyl silicate -Tegovakon V- and protected with a water repellent, oligomeric polysiloxane -Tegosivin HL- 100-, (both from Th. Goldschmidt, FRG).

The AE/MS, was monitored in the 100-300 KHz range. The preliminary results show a very different AE/MS behaviour between the non-treated and the treated specimens.

The cathodoluminescence characteristics of more than 500 white marble samples from known classical quarrying sites and surrounding areas in Greece, Turkey and Italy were analysed to develop a rapid and low-cost method for the characterization of white marbles. In most cases, the observed cathodoluminescence colors, intensity and intensity distribution form a distinct “cathodomicrofacies” which is commonly unique for a given area, quarry or parts of a quarry.

In cases where the cathodomicrofacies is common to more than one quarrying area, the stable isotope signature of the white marbles provides an effective complement to cathodoluminescence, and allows additional distinctions between marbles to be made.

The study of field samples from ancient quarrying areas can identify the source of white marble used for ancient sculptures and buildings. This new approach has been successfully tested on ancient marble sculptures and sarcophaguses from the collection of the Art and History Museum in Geneva.

Application of a non-destructive energy-dispersive XRF technique, involving use of analytc/Compton net peak ratios, has greatly increased the analytical potential for the study of obsidians in archaeological assemblages. Contrary to reported conclusions for obsidians from the Coso Volcanic Field of southeastern California, however, the method lacks the precision associated with powdered-specimen, thin film, and other more rigorous techniques. Tests have shown that changing the orientation and/or placement of an archaeological artifact in a sample slot will produce widely divergent determinations of ppm concentrations for most specimens. These results indicate that discriminating between some chemical subsources at Coso cannot be accomplished reliably.

The beauty of a carved pre-Columbian jade defies description. Unfortunately, thousands of fake jade pieces are in museums and private collections. In the study of authenticity, it is necessary to scientifically analyze the surface, observing the changes produced by reactions with the environment, mostly aqueous soil mixtures.

Prehistoric archaeology has profited enormously from the expanding role of technological examination of artifactual materials, particularly in the past couple of decades. Indeed, the rapid growth of materials sciences studies has evidently begun to outpace the capacity of many prejistoric archaeologists to accomodate the results of technological analyses into anthropological models to explain perceived changes in the prehistoric archaeological record. The sheer numbers of published technological reports, which increasingly appear in a growing number of specialized journals and other publications, account for some of the communications lag among prehistorians and smaterials scientists. But long-held and persistent myths and “hearsay” evidence also contribute to a widening gap between relevant data and critical evaluation.

The case study presented below compares scenarios that purport to explain striking contrasts in the northern and southern parts of the Levant during the middle part of the Neolithic period, particularly from ca. 6,500-5,000 b.c. One hypothesis (climatic change) is briefly dismissed; the other hinges principally on the environmental implications of plaster production that characterized the cultures of the region. The “collapse” of the southern Levantine settlements is understandable when the specific requirements of lime plaster manufacture are taken into account, while the conditions for the persistence of long-term site continuity in the northern Levant are clear under the less pressing environmental demands of gypsum plaster production.

Fired clay vessels began to be produced in the Near East about 8,000 years ago; these vessels were utilitarian, undecorated, fired at a relatively low temperature and seem to have been derived from brick-making practices. By about 6,000 B.C., pottery making was a well developed craft and the use of slip coatings, ocher red and black decoration with control of oxidation-reduction during firing, impressed designs, rouletting, manganese oxide and spinel black pigments, coil and slab construction, burnishing, joining, paddle and anvil shaping, carving, trimming and preparing clays by decanting a suspension were widely known [1]. By the fifth millennium, these techniques had become quite sophisticated and were used to produce polychrome wares and glossy surfaces. Painted and glazed designs were confined to decorative motifs appropriate to a particular technique and culture.

Ancient Near Eastern literature includes numerous metaphors, similes, and other figures of speech referring to ceramics. This paper presents selected examples of Sumerian, Akkadian, Egyptian, and Biblical texts using clay, empty or filled vessels, potsherds, potters and the tools of their trade, and potters′ quarters. By examining systematically for the first time the literary, art historical, and archaeological contexts for ceramic imagery, new light may be shed on the role and meaning of ceramics in the ancient Near East. Among the topics considered are: (1) the importance of ceramics in creation imagery; (2) the nature of ceramic death and destruction imagery; (3) ceramic imagery with cornucopial connotations; and (4) literary perceptions of clay, pottery, and the status of potters. The material assembled in this study adds significantly to the evidence gleaned from stylistic and technical analysis of ancient Near Eastern ceramics.

It is difficult to assess the relative importance of technical and non-technical factors in inferring modes of technological decision-making in prehistory. Examination of pottery use technology among the Kalinga using both ethnoarchaeological material and laboratory analysis demonstrates the importance of not only technical (physical properties or functional), but also behavioral or social aspects of technological choices. Kalinga consumers may select pots for functional superiority, or for reasons of village allegiance. Explaining the resulting pattern in the material record requires attention to both technical and behavioral aspects of the pottery technology.

Celadons--stonewares with pale green or greenish-blue glazes--have a rich and varied history in ancient China that begins in the Eastern Han period (A.D. 20-220) and extends nearly 1500 years [1]. The initial development of celadon wares in Korea probably dates to the late 9th century [2,3]. The zenith of production was in the llth-12th centuries, during the Koryŏ dynasty (918-1392); celadons continued to be produced into the 15th century. In form and type, the earliest Korean celadons were clearly based on Chinese models, although by the middle of the Koryo period uniquely Korean forms and decorative techniques had been developed, notably the use of white and black inlays. During the Koryŏ period, celadons were probably produced exclusively for court circles and for use in Buddhist temples. Some 270 Koryŏ period celadon kilns have been found to date. The greatest concentration (about 240) occurs in Chllla province in the south; the major areas of production were around Kangjin and Puan.

Industrial and medical x-radiography can be used in a new manner analogous to back-scattered electron microscopy to identify the approximate mineralogy of rock temper particles in ceramics, but without their destruction by thin-sectioning and at very low cost. Mineralogical traits similar to those applied in petrography to identify mineralogy are visible in a magnified radiograph. They include particle radiographic grey level contrast, which varies with specific density and mineralogy; morphology; cleavage; and internal texture. Blind tests that evaluate the specificity and accuracy of the method are presented.

Ceramic analysis with an electron microprobe and thin-section petrography are used to investigate prehistoric exchange among the Hohokam of the Salt River valley, Arizona. These complimentary techniques can be useful for resolving the special problems that arise when studying ceramic exchange over short distances.

A description of the excavations of the Qin pottery army is given first. Analyses of the raw materials are reported. The construction techniques of the soldiers and horses are detailed separately. Lastly, analysis and reconstruction of the firing technology and post-fire paints are presented.

Copper red glazes made at the pottery center of Jingdezhen during the Ming and Qing dynasties are one of the most famous and precious porcelain products of China. They were based on earlier technology developed in the Tong-guan kiln in Tang dynasty and on the Ru and Jun wares of the Song dynasty. The earliest copper red glazes appeared as early as the late Yuan dynasty. The dazzlingly beautiful altar red and ruby red products were created at Jingdezhen in the Yongle and Xuande periods of the Ming dynasty. Other copper reds created at Jingdezhen were the Longyao red of the Kangxi period and the imitation Jun, flambe amd others of Yongzhen and Qianlong periods of the Qing dynasty. Chinese copper red glazes have been held in high regard throughout the world, and many have wondered at their complex and sophisticated technology. Through analysis, we unlock some of the technical secrets of these famous wares in order that more people may appreciate the technical excellence underlying the visual appearances of these wares and that these glazes may be replicated better by contemporary ceramic factories in Jingdezhen.

Seven examples of Jingdezhen copper red glazes were analyzed by scanning electron microscopy, x-ray diffraction, refiring tests and microprobe analysis to determine the compositions, microstructures and firing temperatures.

Unlike most ancient faience, which consists of a quite porous and weak body coated with a glassy glaze, much Harappan faience has a quite dense body with a continuous glassy phase and a relatively thin skin of glaze. A multiple-step grinding and fritting process of manufacture was used to make the finely ground, uniformly blue-green and other colored bodies. Intentional additions of glass frit and clay are postulated. The Harappan faience bodies are particularly strong, compared with contemporaneous faience from Southwest Asia and Egypt, because Harappan faience is more dense, because differential thermal contraction during cooling places the continuous glassy phase in compression, and perhaps also due to crack deflection toughening. A similar technology is not found in Egypt until much later during the New Kingdom about 1450 B.C., and then only glass is added.

The socio-cultural reasons for the development of such a specialized technology probably resides in the properties required of the particular type of artifact in which this technology is most often found, that is, bracelets. Bracelets, or bangles, were worn on arms and legs; most often several were worn at a time. Such use required the bracelets to meet criteria of increased abrasion resistance and impact strength, and thus an innovative technology was developed to meet these needs.

This paper presents the results of a program of mineralogical analysis aimed at the elucidation of raw material acquisition and paste preparation practices among Roman-period potters in the Orte/Vasanello area of the central Tiber Valley of Italy. A study of modern folk potters at Vasanello revealed a complex pattern of clay utilization. A selection of local clays, pottery produced by Vasanello potters, and ceramics from two Roman ceramic production sites was subjected to mineralogical analysis (x-ray diffraction, petrographic) for purposes of comparison. The results indicate that similar clay sources were exploited by potters in both periods, and that the materials obtained from these were likely employed for similar functional varieties of pottery.