Fifty cent coins and quarters made before 1964 were made of 90% silver. This is considered jeweller's quality silver so can easily be made into a ring. Kennedy Half Dollars can be found at coin shops or on ebay for four or five dollars a piece. Begin with an anvil which can clamp onto a table. This will allow you to hammer without damaging the table. If you don't have a anvil, you can use any flat surface that is sturdy and made of metal. Next, take a small hammer, position the coin on its edge then hammer the edge as you slowly rotate the coin. The edge will begin to push out and the lines along the edge will begin to disappear. After about an hour of hammering, some nice facets will have formed along the edges. The coin may warp if you hammer too hard or don't hammer straight. Next, place the coin in a pipe wrench, vice grips or clamp so it will hold tight while it is being drilled. Once the coin is secure, drill a hole through the center of the coin. Next, put on your safety goggles and use a dremmel tool to carve out the center of the coin completely. Polish it off and your ring is complete.