There are two ways to create a necklace with a coin charm. One involves putting a hole through the coin itself, and the other way requires you mount the coin inside a bezel. If you found a "lucky coin" on the ground, and you don't mind putting a hole in it, the first option might be fine for you, but if putting a hole in the coin is out of the question, you can easily place it in a bezel yourself without too much trouble.
Things You'll Need
Lay your coin on a hard flat surface such as a rock or a slab of concrete that you don't mind chipping. Position a cold chisel about one-third of the way from the top of the coin. This is where you'll make the hole.
Tap the chisel with the hammer to make a small dent. Start out with gentle hits, and then increase the pressure as you create a deeper dent. Stop before you penetrate the coin.
Put the tip of a nail in the middle of the dent, and hit the head with your hammer until it goes all the way through the coin. Put an open jump ring through the hole, and slip the end of a chain through it. Close the chain, and your coin necklace is ready to wear.
Measure the diameter of your coin, using millimeters as a unit to get a more accurate measurement, then measure the thickness of the coin. You need to know the exact dimensions so that you can buy the right size bezel.
If you don't already have one, buy or order a bezel in the size that you need. You can find these at jewelry stores or online. Choose the bezel that will look best with your coin, because it will add to the overall look of the necklace. If you don't want the bezel to distract from the coin itself, choose a bezel with a plain edge.
Open the bezel with a jeweler's screwdriver. Remove the tiny screw at the top that holds the bezel together, and gently open the bezel by pulling the two sides away from each other just enough to fit the coin into the middle.
Position the coin in the center of the bezel, and push the two sides back together. Replace the screw at the top, and slip the loop at the top of the bezel on a necklace chain.
After making a hole in a coin, sand down the edges to prevent them from scratching anyone who wears the necklace.