Thin-Section Petrography in the Use of Ancient Ceramic Studies

The potential of thin-section petrography for the analysis of ancient ceramic materials, such as pottery vessels, figurative objects and building materials made of fired clay, was already recognized during the 19th century, but its use has become more intensive during the past 80 years. Since pottery is the most common and typologically datable artifact in archaeological excavations from the pottery Neolithic period onwards (some 7000–8000 years ago), the analysis of pottery, including its composition, is a central component of archaeological research. As ceramic materials are made of fired clay, which in turn is procured from soils, weathered rocks and geological formations, the mineralogical composition of the ceramic artifacts represents the clay sources. The study of the mineralogical and rock fragment composition of thin sections of ancient ceramic artifacts can yield the characterization of the clay and soil type and thus the geographic location or area of the clay source. Since in antiquity we assume clay was not precured from a distance of more than one day’s walk from the production site (‘site catchment area’), the production location can be detected as well. Thus, petrographic analysis can identify the trade of artifacts and commodities (if the ceramics are containers) in antiquity, which can shed light on political and cultural links and trade between ancient societies and their economic and social structure. In addition, since clay was often treated by ancient potters to improve its quality (levigation, clay mixing, addition of temper), technological aspects of the production sequence (chaîne opératoire) can also be acquired by petrographic analysis. Today, petrographic analysis is part of many standard studies of ancient pottery. While it is an old and relatively ‘low tech’ method, the accessibility of the equipment needed and its high analytic potential maintains its important and common position in archaeological research. This article describes the method and its analytical potential from the archaeological point of view and briefly mentions several archaeological case studies exemplifying its wide and diversified potential in the study of ancient ceramics in past decades.