What Is Tufa Casting in Native American Jewelry?
Tufa casting is a silversmithing technique in which molten silver is poured into a mold carved from tufa, a porous volcanic tuff stone found throughout the Southwest. Each mold carving is unique, and the stone is often destroyed or deformed in the casting process, making tufa-cast pieces inherently one-of-a-kind in their surface texture, even when the overall form repeats.
Mateo's Field Notes
Adair documents tufa casting as one of the more demanding traditional techniques, noting that the preparation of the mold alone requires significant skill and patience. "The carver must work in negative," he writes, "seeing the finished piece in reverse, accounting for shrinkage as the silver cools and for the sprues that will feed the pour" (The Navajo and Pueblo Silversmiths, 1944, p. 86). A poorly vented mold traps gas bubbles in the cast; a poorly gated mold produces incomplete fills where the metal solidifies before reaching the extremities of the design.
The surface character of tufa-cast work is its most immediate identifier. Tufa stone imparts a granular, slightly rough texture to the silver as it solidifies against the carved stone face. This texture is not a defect; it is the signature of the process. Smiths may choose to leave it fully intact, or they may selectively polish certain planes while retaining the cast surface in recessed areas, creating a contrast that defines the piece's visual language.
The carving itself is the creative act. Unlike a commercial mold that can be reused indefinitely, a tufa mold degrades with use—the stone desiccates, the carved channels erode, and the surface texture changes. Many Navajo and Hopi smiths treat each mold carving as an artwork in its own right, sometimes keeping exhausted molds as studio objects. The design vocabulary in tufa casting tends toward bold, geometric forms—sand-cast work handles fine detail better, but tufa's natural surface energy suits broad, direct compositions.
Ric Charlie and Robert Mitchell, both Navajo, have continued tufa casting traditions that run through multiple generations. Charlyn Reano of Kewa Pueblo brings Pueblo design sensibility to a technique more commonly associated with Navajo smiths, demonstrating how tufa casting crosses tribal boundaries. Preston Monongye's Hopi tufa work is documented in several museum collections and represents one of the technique's more inventive mid-century expressions.
Collector's Handbook
- Read the surface texture. Legitimate tufa casting leaves a distinctive granular surface where the silver touched the stone. This texture is irregular and directional, following the grain of the specific stone used. Machine-cast or die-cast pieces attempting to simulate tufa casting usually show uniform surface treatment that lacks this organic variability.
- Examine the sprue mark. Every tufa casting has a sprue—the channel through which silver was poured—that must be cut and filed after casting. Look for the filled or refinished area, usually on an edge or back of the piece. Its presence confirms casting; its quality of finish reveals care.
- Assess the design for casting suitability. Tufa casting handles bold geometric forms, large open areas, and deep channels well. Extremely fine lines or tight detail are more characteristic of sand casting or fabricated work; very fine claimed tufa-cast detail warrants closer inspection.
- Ask about the mold. A smith who tufa-casts can usually describe the stone source, the carving process, and whether the mold survives. This conversational knowledge is hard to fake and deepens the piece's provenance.
Masters of Tufa Casting in Our Directory
Charlyn Reano (Kewa) · Robert Mitchell (Navajo) · Ric Charlie (Navajo) · Jonah Hill (Hopi) · Preston Monongye (Hopi) · Philander Bryan Begay (Navajo)
Primary Sources
- Adair, John. The Navajo and Pueblo Silversmiths. University of Oklahoma Press, 1944.
- Hougart, Mark. Hallmarks of the Southwest. Schiffer Publishing, 2000.
Related Entries
Sand Casting vs. Tufa Casting · Stampwork · Repoussé · Glossary