USING OPTICAL COHERENCE TOMOGRAPHY TO EXAMINE THE SUBSURFACE MORPHOLOGY OF CHINESE GLAZES

Optical coherence tomography (OCT), a new method for ceramics research, is a nondestructive, three‐dimensional tomography system, which provides subsurface morphology visualization of samples based on the refractive index or dielectric constant differences in the target specimen. In this study, seven shards from different Chinese kilns of Song and Yuan dynasties (10–14th centuries) were scanned to visualize the subsurface morphology of their glazes. The images revealed unique phase assemblage modes in different samples. The results suggest OCT may be used to identify ceramics and provide information about their manufacturing technology.     

Optical Coherence Tomography for the non-invasive investigation of the microstructure of ancient Egyptian faience

Optical Coherence Tomography (OCT) is a non-invasive subsurface 3D imaging technique based on the Michelson interferometer. The non-invasive nature of OCT and its speed of acquisition makes it possible to image large volumes of intact objects to yield a complete overview of the microstructure. The production methods for ancient Egyptian faience were first investigated using scanning electron microscopy (SEM) imaging of the microstructure in polished sections and microprobe analysis of the composition of the glass phases. These studies were based on original Egyptian faience objects and laboratory reproductions of faience beads made using three different production methods. The microstructure of the same laboratory samples and the Egyptian faience objects from the British Museum Research Laboratory Collection are re-examined using OCT. It is found that OCT virtual cross-section images can be used to group ancient faience objects into three categories on the basis of the morphology of the surface glaze layer and the glaze/core interaction layer. The OCT images correspond well with SEM images of polished sections of ancient faience objects and laboratory reproductions. The virtual cross-sections produced by OCT are somewhat limited by the penetration depth, which is affected by the high absorption coefficient of the material and, therefore, cannot always provide information on the presence or absence of interparticle glass that binds together the quartz particles in the core. Nevertheless, the top two layers are well imaged and since OCT images can be obtained rapidly and without the necessity of removing a sample, the method can be applied to a very much wider range of ancient faience objects than is possible by SEM examination of polished cross-sections. In summary, this paper examines to what extent OCT can assist the investigation of the production techniques of ancient Egyptian faience.     

The Use of Ethnoarchaeology for the Archaeological Study of Ceramic Production

Ethnoarchaeological studies have longed served as a critical source of hypotheses, comparative data, and explanatory frameworks for archaeologists interested in describing and explaining ceramic production. In this paper, I lay out the central questions addressed by archaeologists studying craft production, discuss how ethnoarchaeology has contributed to our understanding of ancient production systems, and suggest avenues of further research that can benefit archaeological investigation of the organization of ceramic production.     

Matchlocks, Flintlocks, and Saltpetre: The Chronological Implications for the Use of Matchlock Muskets among Ottoman-Period Bedouin in the Southern Levant

This paper examines the chronological implications for the prolonged use of matchlock muskets by the Bedouin during the Ottoman Period (1453–1918). Although the technology behind the matchlock ignition system is from the fifteenth century, this weapon was used by many Bedouin until the beginning of the twentieth century. As a result, the presence of gun parts from matchlock muskets poses a potential problem for identifying Bedouin occupations from the eighteenth and nineteenth centuries in the southern Levant and in northern Arabia. This issue is heightened by the paucity of diagnostic artifacts found at archaeological sites associated with the Bedouin during the Ottoman Period.