Egyptian Faience: Technology and Production

See works of art
  • Wall tiles from the funerary apartments of king Djoser
    48.160.1
  • Inlay Depicting a Falcon with Spread Wings
    26.7.991
  • Statuette of Isis and Horus
    55.121.5
  • Amulet of the God Bes
    26.7.878
  • Standing Hippopotamus
    17.9.1
  • Jerboa figurine
    26.7.899
  • Crocodile amulet
    1989.281.96
  • Broad Collar of Wah
    40.3.2
  • Openwork faience ring
    74.51.4540
  • Lotiform Chalice
    26.7.971
  • Design amulet in the form of a duck
    17.190.2011
  • Wedjat eye Amulet
    17.190.1639
  • Shabti of Seti I
    26.7.919

Works of Art (14)

Essay

In ancient Egypt, objects created with faience were considered magical, filled with the undying shimmer of the sun, and imbued with the powers of rebirth. For Egyptians, the sculptures, vessels, jewelry, and ritual objects made of faience glimmered with the brilliance of eternity. While faience is made of common materials—quartz, alkaline salts, lime, and mineral-based colorants—it maintained important status among precious stones and metals. Faience may have been developed to simulate highly prized and rare semi-precious blue stones like turquoise. This man-made substance allowed the Egyptians to make a wide variety of objects covered in shiny, bright blue glaze—a color that was closely linked with fertility, life, and the gleaming qualities of the sun.

Faience first appeared at the end of the fifth millennium B.C. and has occurred in various forms up to the present day. It is possible that its invention might have occurred in the ancient Near East following the development of an alkaline glaze on quartz stones. Its technological refinement and major triumphs, however, were surely accomplished in Egypt. Some of the earliest faience objects made in Egypt were beads, soon followed by small votive temple offerings and royal tomb objects. Faience was inlaid into furniture and into walls as tomb and temple decoration (48.160.1; 26.7.991). The most recognizable forms of faience are small figures of gods (55.121.5; 26.7.878), animals (26.7.899; 1989.281.96), and shabtis (26.7.919), as well as jewelry (40.3.2; 74.51.4540), amulets (17.190.1639), scarabs, and vessels (26.7.971).

Technical Description of Faience

The term “faience” is actually a misnomer, as it also refers, more accurately, to the maiolica originating from Faenza and other towns in Northern Italy in the late fifteenth century A.D. Maiolica is earthenware known for its bright colors applied on white tin-opacified glaze; Egyptian faience is neither earthenware nor tin-glazed. However, since there has been little agreement on an alternative term, “faience” remains the most commonly used.

Egyptian faience is a ceramic material with a siliceous body and a brightly colored glaze. In addition to silica, faience also contains alkaline salts (the source of which was either natron or plant ash), minor amounts of lime, and a metallic colorant. Although faience was made in a range of bright colors, the turquoise blue color so characteristic of the material is created with copper. During the firing process, the alkali (acting as a flux) and the lime (acting as a stabilizer) react with the silica in the core to form a glaze on the surface.

Observed in cross-section, the microstructure of faience reveals at least two different layers of material: an inner core and an outer layer of glaze. The core is friable and porous, and is made up of particles that can vary in size from fine to coarse. These particles tend to be white but can be very pale blue, green, brown, or gray, depending on impurities contained in source materials. The bulk of this core material is made up of angular quartz grains without any visible clay particles, and always has the appearance of being artificially powdered. The quartz grains in the core are coated and held in place by small amounts of a soda-lime-silicate glass.

This interstitial glass appears colorless and transparent in cross-section, but in the glaze on the exterior surface one observes a very different optical effect: translucency. The crushed quartz core visible beneath the glaze creates an irregular white ground that scatters the light. The result is a diffuse, almost variegated appearance of depth that closely resembles the optical qualities of turquoise. The way light hits the interface between the core and the glaze gives an impression of brightness as well as translucency. Steatite, a soft, easily carved stone to which similar glazes were applied, is much smoother at this interface and does not scatter light in the same way faience does (17.190.2011). This distinction might offer one explanation as to why faience, which is difficult to form, might have replaced glazed steatite as a preferred method to produce for producing prized objects.

Raw Materials

The humble raw materials for creating faience were available in the Egyptians’ immediate surroundings. Silica could have been acquired from fine desert sands or from quartz rock, quartz pebbles, or silicaceous limestone, all of which are abundant in Egypt. Quartz sand of the purity contained in faience cores is extremely rare. Quartz rock occurs as veins in igneous rocks of the eastern Egyptian desert. Such rock would have produced good material for faience, but it was not easily accessible and would have required significant labor to acquire. White quartz pebbles seem the most likely source of silica for faience, as they are plentiful in the desert and easy to acquire. Mining and carving of granite or sandstone might have provided a significant source of silica to the faience industry. Some scholars have proposed that the raw materials for faience were obtained as a by-product of hard stone drilling. Copper tools were used with abrasive sand to drill or saw granite and hard limestone artifacts. The waste powders from this process consisted of quartz and lime from the limestone, and also contained particles of copper from the drill, potentially providing a ready source for the materials to make faience.

Egyptian soil is rich in saline substances such as niter, natron, alum, rock salt, and sea salts—all of which could have provided the alkaline component for faience. Niter forms as an efflorescence on the surface of the soil during dry periods. Natron is collected from the saline encrustations of dry lakebeds of Wadi Natrun in the west of the Nile Delta. Rock salt and alum are mined from the earth.

Making Faience

There were various manufacturing methods for faience, but the most common was a self-glazing technique referred to as the “efflorescence method.” To make faience with this glazing method, water-soluble alkaline salts are combined with powdered quartz, some lime, and a colorant (e.g., copper originating from metal shavings or crushed copper-rich stones such as malachite). The dry ingredients are mixed with water to create a paste that is then formed into the desired shape. As soon as the paste is formed, one starts to notice the difference between faience and clay. Faience is thixotropic, which means that the paste appears to be a solid, but becomes more fluid and slumps as it is modeled. A paste made of corn starch and water exhibits similar behavior.

Not only is faience paste thixotropic, it is also non-plastic. It cracks when bent, and has little ability to support its own weight. Due to these physical properties, faience cannot be formed into objects using the same techniques as potter’s clay; throwing faience on a wheel to make vessels is possible, but this technique was only used to a limited extent. Small amulets and beads could be formed by hand-modelling, but one of the most common ways to shape faience was with clay molds, as is evidenced by the multitude of faience molds found in the archaeological record (21.9.23). The paste can also be worked into a slab by shaking and patting to create flat objects such as inlays or tiles. Another technique for working with faience is to form the paste around an organic core that burns away during firing. A layer of paste was either modeled around the combustible core or it was dipped into a slurry of faience ingredients. There are examples of hollow faience fruit that were made by coating actual fruits. The holes in these objects correspond to where the stem was located.

Larger objects made of Egyptian faience exist, but are less common. Such objects would have been a challenge to create and were likely hand-modelled rather than made in molds. Strategic methods, such as modelling separate parts that were then partially dried and joined together, would likely have been used (26.7.971; 17.9.1). Examples of large faience objects indicate the level of mastery achieved in this medium and reflect the fact that faience makers had an intimate understanding of their material and firing methods.

In addition to the efflorescence method described above, there are two other glazing techniques: direct application and cementation. These glazing methods aren’t necessarily mutually exclusive—they might be used alone or in combination. Direct application is similar to the modern-day method of glazing a ceramic object in which a glaze slurry is applied to a clay object. The glaze is applied to the pre-formed faience object by brushing, dipping, or pouring. Cementation is a self-glazing technique in which a formed, unglazed faience core is buried in a glazing powder. This powder contains a high percentage of flux, which partially melts and reacts with the silica in the core to form a glaze. After firing, the glazing powder is broken away from the object without sticking to the surface.

Whatever method is chosen for shaping and glazing, the dull, dry pieces must be fired in a kiln to reveal their brilliant color. During firing, the alkaline components (e.g., the salty crust formed with the efflorescence method) react with the ground quartz, copper oxide, and lime to form a glaze. Most ancient faience objects have glaze covering their entire surface, and most show no traces that indicate how they were supported in the kiln during firing. Small conical and spherical kiln supports have been found, but there is little other archaeological evidence of kiln furniture. The lack of archaeological evidence relating to firing makes it difficult for the modern scholars of faience to reconstruct how the kilns were stacked. Some have suggested that faience workers dusted their kiln shelves with a non-wetting powder such as hydrated lime, ash, or even cementation powder. Studies have shown that faience was fired at a temperature between 1598°F (870°C) and 1688°F (920°C). If temperatures in excess of 1832°F (1000°C) are achieved in the kiln, then the glaze begins to bubble excessively and flow off the object.

Close study of Egyptian faience will reveal a wide range in the quality of objects in terms of both modeling and firing techniques. The ancient Egyptians placed a high value on this medium because of the brilliant blue color that could be created with humble, readily available components. Consequently, Egyptian faience persisted for an astonishing four millennia in the Nile Valley.

Carolyn Riccardelli
Department of Objects Conservation, The Metropolitan Museum of Art

December 2017

Citation

Riccardelli, Carolyn. “Egyptian Faience: Technology and Production.” In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. http://www.metmuseum.org/toah/hd/egfc/hd_egfc.htm (December 2017)

Further Reading

Friedman, Florence Dunn, ed. Gifts of the Nile: Ancient Egyptian Faience. New York: Thames & Hudson, 1998.

Nicholson, Paul T. Egyptian Faience and Glass. Buckinghamshire: Shire Publications, 1993.

Vandiver, Pamela. “Technological Change in Egyptian Faience.” In Archaeological Ceramics, edited by Jacqueline S. Olin and Alan D. Franklin, pp. 167–79. Washington, D.C.: Smithsonian Institution Press, 1982.

Caubet, Annie, and Geneviève Pierrat-Bonnefois. Faïences De L'antiquité: De L'égypte à L'iran. Paris: Musée du Louvre, 2005.

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