Beautiful silver jewelry is a well known icon for the Navajo, or Dine, people. But how are they able to create such intricate work out of silver? One method was to use a mold carved from tufa stone. Tufa is a type of limestone that is relatively easy to carve and found in the mid-west.
First, a stone is cut in half, and a reverse image is carved on the inside of the stone. Next, air vents and a channel for the molten silver are carved into the stone. The inside of the mold is then flame treated to keep the silver that will be poured inside from sticking to the stone. Following that, the mold is bound together using leather strips.
When the mold is complete, silver is heated until it is molten. The artist measures temperature by paying close attention to the color of the metal as it heated. When it reaches the correct color, the silver is poured into the stone and gravity pulls the molten metal into the design. When cooled, the leather is removed from the stone and the mold is opened to reveal a beautiful, finished piece of work. Unfortunately, the extreme heat of molten metal only allows for the mold to work a few times before it cracks.