Settings and Tools
Empty settings for both cut stones and standard-sized cabochons are available from jewelry suppliers. When choosing a metal, consider that pure silver and gold are softer and therefore easier to work with. However, their softness means that they will bend with daily use, and your stone could become loose and fall out. Sterling silver and karat gold are more durable but are harder to work with. The lower the gold content in karat gold, the harder the metal. For example, 10K gold is harder than 18K gold. With some settings, you may need a pair of pliers to gently squeeze the prongs together. Specialized pliers for this purpose are called prong jaws.
Other tools you will need include a metal burnisher to bend the metal over the stone to hold it in place. Rounded burnishers are less likely to mar the metal. Because tool marks are likely to appear on the metal over the stone, you also may need metal polishes in various grits. Coarser grits will take out deeper marks, while fine polishing grits shine the setting.
Cut Stones
Although cut stones can be placed in a bezel setting, which has a metal lip bent down around the edge of the stone to hold it securely, most people use pronged settings that raise the stone above the finger. This allows light to pass through the bottom of the stone, thus creating interesting visual effects.
To set a cut stone in a pronged setting, you may need to adjust the prongs until the stone sits squarely in indentations cut into the prongs. Squeeze the prongs together to loose-set the stone. In settings with very deep indentations or grooves, this may be all you need to do. However, for higher-quality or softer-metal settings, you may need to bend the prongs over the stone using a burnisher.
Once the stone is set, polish the setting. If you are careful not to leave tool marks, polishing may not be necessary.
Cabochons
Most cabochons are set with a bezel. Unless you are making your own setting, choose a standard-sized cabochon and a standard-sized setting. To set the stone, drop it into the setting and bend the bezel over the stone. Do this in several stages, working your way slowly around the stone. Be careful not to create a fold in the bezel.