Know About the Tufa Cast Method of Silver Casting

Tufa is a highly porous stone that, when used as a mold for casting, creates a unique texture. Tufa is often used by Native American artists in the creation of beautiful jewelry pieces. It was in the 1800’s when the Navajo artists discovered the tufa method of silver casting.

The labor-intensive tufa cast method requires artists to choose a stone of the desired size, which they then cut into half and rub together to create a flush surface. A hole the size of a cone is then carved on top of the stones (this is called the sprue hole). The sprue hole is where silver will be poured into. To help air escape and to keep the final bracelet cast from bubbling, other holes are carved onto the side of the tufa stone.

Once the mold is done, the artist will carve out the design onto the flat surface inside the hole. The negative space that has been carved away will then be filled with molten silver. Once the carving is done, the tufa stone will be carbonized with the use of a torch. The two halves of the tufa stone will be bound together with clamps.

After the mold has cooled, the hardened piece along with the excess metal in the sprue hole is removed. Some artists will clean and sand the tufa stone to recreate jewelry pieces. The final step in creating jewelry using the tufa cast method is the shaping of the metal. For example, bracelets will be bent to create a curve for the cuff.

The tufa cast method originated with Navajo smiths but has spread to other tribes and passed on to the following generations. Modern artists of make use of furnaces or gas torches to melt silver, unlike before when Navajo silversmiths had to fill up pottery containers with silver coins and then let them melt under embers of fire.