Tufa stone is a soft, fined-grained stone which is easy to cut and carve. Found in Arizona and New Mexico, tufa is used to make molds for casting gold and silver jewelry &mdash a method used by American Indians since the late 1800s.
The traditional method of tufa casting was used to make high-profile shapes that were easier to accomplish by carving a deep design in tufa stone that would hold the molten silver until it cooled and assumed the form of the mold. Bowguards (ketohs), bracelets, and najas were all traditionally made with this technique.
For more than 70 years American Indian silversmiths had been using tufa casting without much alteration of the technique until the 1950s when Charles Loloma began to experiment with the surface texture. By allowing some areas of the rough-surfaced silver to go unfinished he created a contrast in textures that offered a new look for contemporary Native American jewelry.