by Connor O’Brien
The majority of sea glass originates from mass produced utilitarian vessels, while tableware and art glass are less common sources. The same can be said about sea pottery. Yet due to the immense variety of ceramics, identifying sea worn fragments can be particularly challenging. A good way to start is by classifying shards into one of three categories: earthenware, stoneware, or porcelain. Ceramics are grouped into these categories based on the density and firing temperature of the clay. The clay mixture and body of a ceramic is referred to as paste, whereas the surface coating is known as glaze. Grouping ceramics by paste type is the first step in identifying the origin of a shard, and learning to distinguish different pastes and glazes is crucial to making accurate identifications. (Figure 1)

Top row: Red earthenware fragments, brick and terracotta. The color of earthenware can range from cream white to red, dark gray or tan, depending on minerals in the clay used. It is distinguished from stoneware and porcelain by its relatively low firing temperature, porous and less dense paste.
Middle row: stoneware jug fragments. Stoneware is nonporous, hard and compact, fine textured but not glassy like porcelain. It requires a medium to high firing temperature but does not need glaze to be watertight. However stoneware is often glazed with salt or decorative slip glazes. Slip glazes are glazes comprised of clay in water, applied by dipping or washing the ceramic vessel.
Bottom row: Porcelain fragments distinguishable by the very hard dense body, vitreous nature and white color. Porcelain can be glazed and decorated in a variety of ways.
Investigating traditional and regionally relevant ceramics is a great place to start when studying sea pottery. Understanding the history of production is also very helpful when it comes to identifying and dating shards. For beachcombers in North America, especially those on the shores of the Great Lakes and east coast, stoneware is a common source of sea pottery because it was once popular and locally produced. With basic knowledge of vessel shapes and glaze types it is possible to know the origins of these stoneware fragments, despite the fact that they are highly altered from their original form. An immense variety of products were available in stoneware, the most common being jugs and pots. Learning to recognize the characteristics of these forms is another important part of identifying sea pottery. (Figures 2-5)

Top Row: Decorative cobalt glaze applied to an incised design. Decorative cobalt glaze applied with a sponge, known as spongeware. Decorative cobalt glaze applied to a sculpted pattern. Decorative dot band applied with a rolling tool.
Middle Row: Slip glazed shard exhibiting pop out, a defect formed during the firing process. Slip glazed shard from a jug neck, the curve of the neck influences how the glaze is weathered. Slip glazed shard with concentric lines, small surface ripples left by the potter influence the exposure of glaze to abrasive forces.
Bottom Row: Dark colored Albany type slip glaze, the use of this glaze can date shards as early as 1860. Boarder between Albany type and Bristol type glazes, use of both glaze types dates shards before 1915. Light colored Bristol type glaze, use on both the interior and exterior dates shards after 1915. Note that these dates are approximate generalizations not strict limits.



Stoneware ceramics in North America began with immigrants from Germany, England, and France who brought the craft over seas in the 17th and 18th centuries. Colonists continued to import English and German stoneware well into the 19th century, yet over many generations of master and apprentice, ceramic artisans blended old world techniques and styles to develop a distinctively American variety of stoneware. The earliest American stoneware was made from scratch in small batches and distributed locally. These ceramics were often plainly salt glazed, crudely shaped, and occasionally decorated with cobalt motifs. The nature of ceramics allowed for artistic expression, stoneware creations were individually handmade and often intentionally embellished with a personal touch. For these reasons collectors regard 17th and 18th century American stoneware as a folk art. The uniqueness and relative scarcity of these vessels make them a rare source of sea pottery that is difficult to trace. (Figure 6)

Potters’ firms and their networks grew alongside the development and expansion of the United States. By the 19th century utilitarian stoneware was an essential part of everyday life and potteries were established all across the country. Potters were able to obtain better and more consistent materials, improve their shaping techniques, as well as distribute their wares beyond local communities. These advancements, paired with the increasing demand for American stoneware, lead to a transition from small family businesses to unified potters’ firms. Individuals who specialized in specific tasks of an assembly line began to replace the tradition of master and apprentice. By the turn of the 19th century, the demands for American stoneware were met by the mass production of simple and uniformly slip glazed vessels commonly known today as crocks or crockery. (Figure 7)

The quantity and consistency of mass produced vessels is what makes them common and identifiable. Glaze type can be used to date stoneware to a relative era (Figure 2). The iconic two-toned stoneware with brown Albany type glaze on top and white Bristol type glaze on the bottom began to replace plain salt glazed stoneware during the mid 19th and early 20th century. By the 1920’s, stoneware glazed entirely in white Bristol glaze was favored for the sanitary appearance and easy to clean surface. The great depression effectively ended the era of American stoneware, though it has been continually produced, it can be assumed that most fragments of stoneware sea pottery are near or over a century old. With basic knowledge of these ceramics even ambiguous shards are relatively identifiable. When dating sea found shards, the context and history of the beach is equally important as the history of the fragment and may help provide a more accurate identification. A perfect way to display these beachcombed shards is to store them in a stoneware vessel, such as an open container. (Figure 8)

Works Cited: Greer, Georgeanna H., Chris Williams, and Tina Griesenbeck. American Stonewares: The Art and Craft of Utilitarian Potters. Exton: Schifftler, 1981. Print.
Connor O’Brien lives in Maine and is a college student and an avid sea glass and sea pottery collector. http://www.seaglasssassociation.org