Reconstructing the Materials and Technology of Egyptian Faience and Frit

摘要

This paper presents a research project undertaken at the Cleveland Museum of Art to study and characterize its collection of more than one hundred and fifty Egyptian artifacts made from faience or frit. An overview of the project is presented here, followed by a summary of faience technology that draws upon other published studies as well as the insights gained during this project. Where appropriate, this technological discussion will be illustrated using examples of Egyptian artifacts studied during this project. For some objects discussion will be limited to one or two aspects of manufacture. However, the proposed manufacturing sequence of several key artifacts will be described more fully. A multi-faceted approach to the study of these materials was designed. Examination procedures used to study the collection included microscopy (surface examination using a low-powered microscope, and microstractural characterization of exposed fracture surfaces or small samples using a scanning electron microscope), structural analysis using Xero-radiography, and nondestructive qualitative compositional analysis of glazes and pastes using x-ray fluorescence spectroscopy. Hardness testing using fine metal points graded to the Moh's scale, Munsell color evaluations and qualitative gloss determinations were also employed. Replication experiments were used extensively to understand visual features remaining on the surfaces of objects, to provide comparison standards for examination of fracture surfaces with magnification, and to test the validity of theories on paste recipes and forming practices. The primary goal of the project was to provide accurate descriptions of the materials and technology of each object as possible. This included characterization of technological features such as glaze (probable application method, composition, color, and gloss), paste (grain size, color, hardness, composition, and extent of vitrification) and forming methods (modeling, molding, template, cores, wet working and/or dry working). Careful documentation of these features enabled detailed technological descriptions to be prepared for each artifact. This work also elucidated many aspects of faience production as it may have been practiced in ancient Egypt, and suggested directions for further study. It is hoped that in the future, technological criteria for dating artifacts that cannot be securely dated using traditional typological art historical criteria can be developed by the careful documentation of characteristics of the paste, glaze and forming processes.