Tufa Cast Jewelry

Tufa casting is somewhat complicated, and requires some heavy-duty equipment, but the results are exquisite. This Tufa Casting Tutorial comes complete with pictures, if you're interested in the process. Many Native American silversmiths use this casting method that has been passed down for over a century.

Tufa is soft porous rock made of volcanic ash that is used to form a casting mold. The Tufa Stone is cut to the desired size and shape which often resembles a brick. It is then sliced in half. Usually, a design is carved into just one of the interior sides of the Tufa Stone, but can be carved into both sides to make a two-sided design.


Navajo 18k Gold Cuff Bracelet with Persian Turquoise
By Darryl Begay

After the design is carved into the tufa, the two halves are joined, and tied together with a strip of rubber. A hole is carved into one end for pouring the molten metal into the tufa. The joined halves then become the mold.

The sterling silver is heated in a crucible until it reaches the molten state, then is poured through the hole into the mold. The force of gravity pulls the molten silver down through the channel and into the carved mold. Thus the piece is said to have been gravity cast.

The tufa stone mold is allowed to cool, and then the silver piece is removed. Extra silver from the pour channel are cut off (called debarring) and put back into the crucible to be reclaimed for future use. The carved design is visible, and the Tufa leaves a textured surface on the metal.

The piece is finished by buffing, filing, soldering on findings, setting stones, etc. Jewelry such as a bracelet is cast flat and then hammered into shape.

This is a perfect example of a tufa cast bracelet, which shows the grainy effect left by the porous tufa stone:

Navajo Sterling Silver Bracelet with 14 karat Gold Bear Designs
By Al Joe

Artisans using this method estimate that it takes approximately three days from start to finish to make a medium sized bracelet.

I just couldn't resist the gorgeous stone in this one:

Tufa Cast Sterling Cuff with Turquoise
By Aaron Anderson
Sterling tufa cast with a Damali turquoise

Tags: Native American jewelry, handcrafted jewelry