One way to turn gorgeous gemstones into wearable pendants is the copper foil method. With this technique, a pliable, sticky strip of copper foil is wrapped around the perimeter of a gemstone, coated in flux and covered with solder to create a shiny, strong frame for the stone without compromising its beauty.
Apply Copper Foil
Copper foil comes wound on spools and is available in a variety of sizes. One side contains a removable backing that reveals an adhesive surface. The other side has a thin coating of copper that solder will easily adhere to. Choose copper foil that is wide enough to cover the sides of your gemstone as well as fold over so that about 2 mm of it will extend down the front and back of the gemstone. Think of the copper foil as the foundation for the sturdy metal frame that will eventually hold the gemstone in place. Apply it precisely where you want the metal frame to be.
Brush on Flux
Flux is a substance made with boric acid. It is necessary for all projects that involve soldering because it enables the solder to flow smoothly over the copper foil and adhere to it well. Use a paintbrush to apply flux to all the surfaces of the copper foil once you have adhered it to your gemstone.
Heat and Apply Solder
Position the tip of a rod or tube of solder on the copper foil. Heat the tip of the solder with a soldering iron and use the iron to slowly pull the melted solder around the perimeter of the copper-foil-wrapped gemstone, until you have completely covered the copper foil. Once the solder is cool and solid, it will form a permanent frame for the gemstone.
Attach a Bail
A bail is a small metal ring that is attached to the top of a pendant. It lets you string the pendant on a chain, cord or ribbon. Bails come in a variety of sizes and styles, ranging from simple rings to elaborate filigreed designs. You can solder a bail onto your pendant; just coat it in flux first, and heat only a dab of solder over the joint, enough to attach the bail without creating an unsightly lump of solder.