Roman colored opaque vessel glasses and mosaic tesserae were examined using energy dispersive X-ray analysis, wavelength dispersive X-ray analysis, and scanning electron microscopy in order to identify the origins of the antimony-based glass opacifying agents used in the Roman period. Bindheimite and stibnite were considered as mineralogical sources of antimony, and antimonial litharge was investigated as a metallurgical source of antimony. The refining of antimonial silver ores was discussed as a source for antimonial litharge in the Roman period. The morphologies of the antimonate crystallites, their distributions, and the observed correlations of lead to antimony in the glasses indicated that roasted stibnite was the antimony source for the white and blue opaque glasses and antimonial litharge was the antimony source for the yellow and green opaque glasses. Opaque yellow Roman glasses were found to contain a mixture of clastic, subhedral, and euhedral lead pyroantimonate (Pb2Sb2O7) particles. The euhedral crystallites are a rhombohedral modification of Pb2Sb2O7 that is formed above 900 °C.

Patterned technological behaviors in the production and use of burnt-lime products can be characterized using optical microscopy and image analysis of pétrographie thin-sections to determine the texture (supplemented by X-ray diffraction analysis). Variations in technological styles have been identified in 21 samples from the ancient Maya site of Nakbe, Petén, Guatemala dating to the Middle Preclassic (1,000 B. C. - 300 B. C.) and Late Preclassic (300 B. C. - 150 A. D.) periods. Middle Preclassic floors exhibit a chaotic texture with a highly random aggregate particle size. Late Preclassic modeled stucco or painted fragments have a well-sorted texture with a low acid-insoluble content (<2%). Load -bearing mortar dating from the early Late Preclassic has a matrix with a high acid insoluble content (>15%), the major phases being quartz (-10%) and clays (∼5%). The variations correlate both with the time of occurrence and the function of the end-product. These issues of construction methods and levels of technology contribute data to aid our understanding of cultural development in this area at a critical time when the Maya were formulating power structures.

ICP-MS isotopie analysis of lead ceramic glazes suggests at least two sources were exploited by Ancestral Pueblo potters to obtain the lead raw material, presumably galena (PbS). Five Rio Grande lead glazeware sherds from the Sandia area and two found at Socorro share a common isotopie fingerprint. The temper of one of the Socorro sherds confirms an origin in the Sandia area; petrography of the temper of the second sherd does not tie to any known Socorro source rock. Two other glazeware sherds from Socorro have a distinctly different lead isotopie signature. A fifth Socorro glaze may be a mixture of the Sandia and Socorro lead source materials. The differences in lead isotopie signature thus accord well with mineralogical differences in the ceramic pastes. Lead isotopie signatures generated by ICP-MS analysis are a powerful new tool for grouping glazeware sherds, classifying individual samples, defining lead sources, and delineating trade routes.

Contemporary hand-made Iznik-style ceramics continue to be popular in Turkey. Made in some 50 workshops in Kiitahya and one workshop in Iznik, these wares generally show the same stratigraphy as the traditional Iznik wares produced during the Ottomon Empire from the 15th-17th centuries. While the materials utilized in the modern wares show some similarities to the traditional wares, the modern ceramicists have adopted many modern materials. For this paper, crossections of ceramics from four modern workshops were analyzed in an electron beam microprobe and the results compared with published information on traditional Iznik ceramics.

As part of a broader research scheme intended to examine the relationship between the ceramic and metal industries of Bronze Age Anatolia, a program of compositional analysis by neutron activation was performed on ceramic material dated to the third millennium BC from Göltepe and Kestel, Turkey, the earliest known tin mining and processing sites in the Near East. Fifty-one archaeological samples representing five classes of pottery (crucibles, burnished ware, micaceous ware, fine-slipped ware, and metallic ware) and three local clay samples were analyzed in order to clarify problems related to the sources of the archaeological ceramics. Evidence provided by these experiments indicates that the four classes of domestic pottery and the crucibles derive from at least two distinct sources. One of these sources, the alluvial clay outcrops in the vicinity of Göltepe, was exploited for the manufacture of two types of domestic pottery (burnished ware and micaceous ware), as well as the “industrial” crucible refractories. Metallic ware appears to represent a distinct source group; however, the specific location of the source remains unclear. The geochemical relationship between fine-slipped ware and the other ceramics remains unclear.

From ca. A.D. 150–750 Classic period civilization in Central Mexico was dominated by the city-state of Teotihuacan, a metropolis of at least 125,000 inhabitants located in a northeastern valley of the Basin of Mexico. This polity exercised economic and religious control over a wide area, regulated obsidian tool resources and production, and locally fabricated and also imported a variety of ceramic artifacts. In this report I shall summarize the status of current and ongoing investigations of Classic Teotihuacan period archaeological ceramics by surveying briefly the regional geology, reviewing previous research employing petrography and INAA, and examining the salient results of the analyses to date on two foreign and seven domestic ceramic wares. Lastly, I consider important research problems and suggest cautions for future investigations of ceramics and clay sources.

A study of a ceramic vessel from San Lorenzo Tenochtitlán, Veracruz, México (Early Formative 1550–900 b.C.) was developed using three selected analytical methods: Petrographic thin section, X-ray Diffraction and Scanning Electron Microscopy. The results suggested, that the soil weathering processes on the ceramic vessel generated phenomenons, such as an increase in porosity, a decrease in bulk-density and loss in structural stability.

On the other hand, the presence of amorphous materials (SiO2, FeO3) in the soil, interacted with the ceramic giving it a natural consolidation. The consequences of our study are discussed in detail.

Bukit Tengkorak (Scull Hill) is a Neolithic period rock shelter complex and prehistoric pottery production site in southeastern Sabah, about 5 miles southwest of Semporna in Borneo, Malaysia at GPS N 4 7 20.08 and E 118 37 04.3. It was excavated for a 5-week season in 1995 and another in 1994 by a joint University of Science and Sabah Museum team under the direction of S. Chia. Two areas with volcanic outcrops about 10 meters apart were excavated. A total of 6 one-meter squares, three in each area, were excavated in 5 cm layers. The three rock shelter trenches, G17, G19 and J19, were excavated to the base of undisturbed cultural deposits, about one and one half meters deep. The main archaeological materials excavated from these squares comprised pottery sherds, stone tools, molluscs and fish and animal bones. Thick layers of ash, measuring 50 to 80 cm, were associated with the pottery sherds in the three rock shelter squares, suggesting that they could have been the remnant of an open pit kiln or pit kilns used for firing the pottery. In the lower outcrop, the three trenches R13, S37 and T38, were excavated near earlier archaeological excavation by Bellwood (1). Our excavation in this area revealed large deposits of clays not found elsewhere in this locale that were probably brought to the shelter to be used as raw material for making pottery. No food remains such as animal and fish bones or unworked shells were found in this area, leading credence to the interpretation of this as a craft working area for the production of pottery and stone and shell tools.

Quantitative measures of time and effort as well as assessment of the knowledge base required in each level of textile manufacture (i.e., plant collecting, fiber processing, yarn and fabric formation) result in cost estimates that indicate differences between simply structured materials and complexly structured elaborate materials. These measures were applied to two textiles from a Wilbanks phase (A.D. 950 to 1440) [1] burial of a high status individual from Mound C at Etowah, Georgia [2]. Socioeconomic implications inferred from the resulting analyses include the proposal of craft specialization in the production of complex textiles and of the significance of these complex textiles to Mississippian chiefdoms.

The ancient Lowland Maya are generally considered to have used a limited number of inorganic colorants in their polychrome reliefs due to the lack or inaccessibility of mineral resources, especially during the Late Preclassic period (300 B.C. – 300 A.D.). A notable exception is the manufacture of a blue pigment from indigo and specific types of clay, known as Maya blue, from the Classic Period (300 – 900 A.D.) through Colonial times. Another exception is a recently analyzed cream (or reddish-yellow) colored paint found on exceptionally large architectural polychrome stuccoed sculpture dating to the early Late Preclassic at the site of Nakbe, Petén, Guatemala. The cream paint layer exhibits a dramatic peach-colored fluorescence upon exposure to ultraviolet light. An organic material, extracted with organic solvents from the acid hydrolyzed lime-based plaster surface, was characterized by means of visible light microspectroscopy, FT-IR microspectroscopy and three-dimensional fluorescence spectroscopy. Analysis of the spectra obtained from the cream colorant and comparison with spectra of reference organic materials suggests that anthraquinone derivatives may be responsible for the color, and that these compounds are similar to some of those present in organic red dyes. The cream paint was applied as a single layer with good hiding power overlying the stucco ground. The cream paint is of the same thickness (averaging 15 microns) as the only other paint present on the sculpture, a red paint pigmented with red iron oxide. The presence of organic colorants on exposed architectural features raises particular preservation problems in relation to the increased possibility and rate of deterioration due to environmental exposure of this type of organic colorant in comparison with most inorganic colorants.

Deterioration of monuments, buildings, and works of art constructed of carbonate-based stone potentially can be arrested by applying a combination of chemical passivants and consolidants that prevent hydrolytic attack and mechanical weakening. We used molecular modeling and laboratory synthesis to develop an improved passivating agent for the calcite mineral surface based on binding strength and molecular packing density. The effectiveness of the passivating agent with and without a linked outer layer of consolidant against chemical weathering was determined through leaching tests conducted with a pH-stat apparatus at pH 5 and 25°C. For the range of molecules considered, modeling results indicate that the strongest-binding passivant is the trimethoxy dianionic form of silylalkylaminocarboxylate (SAAC). The same form of silylal-kylphosphonate (SAP) is the second strongest binder and the trisilanol neutral form of aminoethylaminopropylsilane (AEAPS) is ranked third. Short-term leaching tests on calcite powders coated with the trisilanol derivative of SAAC, the triethoxy neutral form of SAP, and the trimethoxy neutral form of AEAPS show that the passivant alone does not significantly slow the dissolution rate. However, all passivants when linked to the sol consolidant result in decreased rates. Combined AEAPS plus consolidant results in a coating that performs better than the commercial product Conservare® OH and at least as well as Conservare® H. The modeling results indicate that there may be a threshold binding energy for the passivant above which the dissolution rate of calcite is actually enhanced. More strongly-binding passivants may aid in the dissolution mechanism or dissociate in aqueous solution exposing the calcite surface to water.

Structural studies to determine the earthquake worthiness of Hagia Sophia in Istanbul have proved that the monument's static and dynamic behavior depends very strongly on the mechanical and chemical properties of these mortars and bricks used in its masonry. So, the cementrtious nature of the mortars not only explains the fact that the monument still stands but also the very large static deformations which it has undergone, since such mortars have a very long curig period from one to two years. According to the analysis of the dynamic data, the strong motion data from a 4.8R magnitude earthquake about 120 Km south of the building was used to determine the first three natural frequencies of the building. These results show a decrease of about 5–10% in the natural frequencies, as the amplitude of the accelerations increases and returns to their initial values, due to the non-linear nature of the masonry. The above mentioned behavior allows the structure to absorb energy without effecting its material properties, irreversibly. The properties of the mortars and bricks leaded to an extensive study, employing several experimental techniques (FOM, OM, XRD, SEM, TEM, TG/DTA). The results indicated mortars with considerable mechanical strength along with longevity. The model used proved to be resistant to the environmental pollution and to the presence of sah, while the gel phase as binder allows for greater energy absorption and the compatibility of the mortar to the original ones allows continuous stresses and strains. Hence, the recreation of the Hagia Sophia is attempted through a reverse engineering approach to simulate the historical mortars.

In order to maintain the archaeological integrity of the site of Boscéaz, one of the most remarkable north of the Alps because of the number and quality of its roman mosaics, it is intended to maintain these in situ and on their original support. This mode of conservation implies many risks, mainly linked to the climatic variations and to the presence of water and salts in the ground and the mosaics. The high degree of damage observed on these mosaics discovered more than 150 years ago illustrates this fact.

The aim of this study has been to establish a diagnosis of the risks linked to the uncovering and the in situ conservation of a mosaic recently discovered (currently covered with protective materials). This diagnosis has been established on the basis of the measurement of the physical and chemical properties of the mosaic and the ground.

It turned out that the rising of salts from the ground to the mosaic would be the major problem and that consequently a dessalaision will have to be carried out. Concerning the choice of the climatic conditions for conservation, the critical zone in which the salts present crystallize was determined. The thermal dilatation of the materials appeared relatively small, but might become damageable in the long term because of a possible hysteresis. The hydrie dilatation turned out to be negligible.

This interdisciplinary study was designed to learn the chemical constituency of organic residues found in tabby using nondestructive analytical techniques such as X-Ray Fluorescence (XRF) and Particle Induced X-Ray Emission (PIXE). Important information pertaining to events of the past can be preserved in organic materials. The related disciplines of historic preservation and archaeology can benefit from the recovery of that information, especially when conducting collaborative research.

The purpose of this study was to evaluate the effectiveness of these two techniques in their ability to characterize the chemical composition of tabby, a building material that incorporates large quantities of shell. Although useful qualitative data regarding the chemical composition of tabby was obtained using both methods, the best results were obtained using PIXE.

These results suggest that PIXE represents a viable and accurate alternative for compositional analysis of materials with an organic component commonly encountered by historic preservationists and archaeologists.

The possibility of using Electron Spin Resonance Spectroscopy (ESR) for identifying the quarries of provenance of classical marble artifacts has been reexamined and applied to the sample case of the so-called “Cipollino Verde” marble. The method gives qualitative and quantitative information on Mn2+ and other paramagnetic impurities present in marble and the assignment is made on a statistical basis, using a properly defined database. Like other, well established, techniques, ESR seldom yields an unequivocal answer to the provenance problem. However, it provides valuable information and, coupled with other methods, reduces the existing uncertainties often leading to the final assignment.

Preservation of building and monument stone exposed to acidic environments relies on the understanding of acidic precipitation deposition processes and damage mechanisms. Presented here is a model which predicts sulfur accumulation in porous limestone subjected to dry deposition of SO2. The model assumes deposition and reaction of SO2 to form a thin gypsum crust on the moist surface of the stone, and subsequent sulfur (as aqueous sulfate) transport and accumulation in the stone interior driven by diurnal wetting and drying of the stone surface. Characterization of the limestone pore structure contributes significantly to the evaluation and interpretation of modeled sulfate transport and accumulation in porous building materials. Predicted sulfur accumulation in the stone interior is dependent on the surface boundary conditions, the stone pore geometry and structure, and the rates and mechanisms of aqueous/solid sulfur partitioning (i.e. adsorption, precipitation and dissolution). Model results are compared to moisture content and sulfur accumulation measured in limestone briquettes exposed to a natural dry deposition environment. The model successfully predicts moisture transport in field-exposed limestone, but overestimates the rate of sulfur accumulation. The model may be improved by quantification of the time dependence of the surface sulfate concentration and better understanding of the sulfate partitioning mechanisms.

Several non destructive techniques are recently applied to assess and evaluate weathering damages. In the present work several macro- and micro- non destructive tests, have been employed, in the Fortress of the Medieval City of Rhodes, for the examination of the weathering: Digital Image Processing for the mapping of the decay patterns, Fibre Optics Microscopy for the examination of the morphological characteristics of the surface, and Infra Red Thermography for the assessment of the humidity distribution within the masonries and the degradation of the stone texture. The results of the above methods are supported by porosity and humidity measurements regarding the evaluation of the microstructural characteristics of the stone and the water percolation within the masonry. It is proved that these three methods can be combined into a reliable assessment tool concerning environmental impact on architectural surfaces and particularly in the form of a thorough characterization of the materials degradation.

Two ‘families’ of polymers applicable to preservation and restoration are discussed: (i) polysiloxane networks generated by platinum catalyzed addition of vinyl silane precursors to hydrogenosilane precursors; and (ii) acrylic compositions generated by redox initiated polymerization of acrylic monomers in the presence of fine spherical acrylic polymer particles. In both cases the end result is achieved at temperatures between ambient and 60°C, and with negligible volumetric shrinkage.

In order to design a scheme to monitor the state of preservation of iron alloys that are found on historic shipwrecks sunk in fresh water, it was first necessary to identify the predominant form of corrosion found on the wrecks. This was done by visual observation, in situ surface pH measurements, and X-ray powder diffraction of the corrosion layers. Once the form of corrosion was identified as pitting corrosion, a monitoring scheme based on photographic recording of the rust-red tubercles was designed. This scheme is simple and nondestructive, both necessary characteristics for the monitoring of submerged historic resources.

Soot deposits that can accumulate on surfaces of a painting during a fire can be difficult to clean from some types of paintings without damaging the underlying paint layers. A non-contact technique has been developed which can remove the soot by allowing a gas containing atomic oxygen to flow over the surface and chemically react with the soot to form carbon monoxide and carbon dioxide. The reaction is limited to the surface, so the underlying paint is not touched. The process can be controlled so that the cleaning can be stopped once the paint surface is reached. This paper describes the smoke exposure and cleaning of untreated canvas, acrylic gesso, and sections of an oil painting using this technique. The samples were characterized by optical microscopy and reflectance spectroscopy.