Friday, April 11, 2014

C is for Ceramics

To an archaeologist, ceramic artifacts have the potential to yield a wealth of information. This is true for both historic and prehistoric sites. Ceramic artifacts are useful to archaeologists not only in determining the age of a site, but can they can also aid in understanding the socio-economic status of individuals or groups of people.

The advent of ceramic technology, that is, the act of sourcing and extracting clay, and constructing a container of a desired shape and size and then “firing” it for durability, stands as a major advancement in cultural evolution, and is a distinguishing characteristic of the Woodland Period from that of the earlier Archaic Period. In Pennsylvania, this shift is generally accepted to have gradually taken place over a period of time 2,750 to 3,250 years ago.

Washington Boro phase Susquehannock ceramic vessel with human effigy applique

In conjunction with other dating methods such as carbon 14, differences in vessel form, decoration, and temper allow archaeologists to further differentiate the Woodland period into Early, Middle and Late sub-periods, and further still into distinct phases within a particular geographic/cultural region.

Ceramics can do more than just aid archaeologists in determining the age of a site. Vessel form can infer function. For example, compare a fine porcelain tea cup to a thick-walled stoneware storage crock. Even without knowing their indended purpose, one could assume they fulfill very different functions just by visual inspection. Also, questions of site type (domestic, commercial, industrial etc.) can at least begin to be answered by incorporating ceramic data into a comprehensive artifact analysis. In a prehistoric context, large and oversized ceramic containers are indicative of storage and communal activities, while more modest size vessels suggest use by a family or individual for cooking and consumption.

17th Century stoneware Bellarmine jug

Historic period ceramics have the potential for even more refined analysis for the archaeologist by virtue of the overwhelming variety of forms and styles of decoration accompanied with maker’s marks and detailed records of dates of manufacture for specific wares. However, not all ceramics are created equal, and some are less useful to archaeologists than others. Plain lead-glazed red earthenware is not a particularly helpful ceramic type in dating archaeological remains as potters began producing this basic utilitarian ware shortly after colonization and nearly identical wares are still made to this day. That is not to say all red earthenware is indistinguishable, just that its ubiquity creates complication and can limit its usefulness.

medium sized red earthenware bowl with clear lead glaze and slip trailed decoration

An example of a ceramic type that has a narrow date range of manufacture, and therefore can be very useful in dating sites or features (assuming the context is valid), is an English ceramic know as Scratch blue salt-glazed stoneware. Records indicate this specific type of ceramic was only in production from 1744 – 1775. Scratch blue salt-glazed stoneware is also considered to be a more refined ceramic and its presence on an archaeological site would be associated with an individual or family with a degree of elevated status in society.

reconstructed scratch blue salt-glazed stoneware teapot 

Ceramics have played a vital role in people’s lives for thousands of years, and will continue to play an important role going forward. Obvious and everyday ceramics include table and cookwares and all manner of architectural elements (floor, roofing, fireplace, bathroom). Less obvious examples include industrial applications such as resistors in computer circuitry and automotive components. Even the underbelly heat shield of the recently retired Space Shuttle is actually a high-tech ceramic tile skin.

As archaeologists attempt to understand people's past behavior, they are keen to realize the potential store of information that ceramic analysis provides. We hope this brief essay encourages you to dig deeper into the world of ceramics, a world that helps us preserve the past for the future.

Noel Hume, Ivor
1976  A Guide to Colonial Artifacts of America Alfred A. Knopf, New York

For more information, visit or the Hall of Anthropology and Archaeology at The State Museum of Pennsylvania .

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