Want to give your girlfriend the best gift ever for her Birthday? How about make a customized silver ring that you can make from quarters made before 1964? (quarters made before 1964 are silver)
Better yet, you could probably engrave something special on the ring when you are done with it.
Do you have a quarter from 1964 or before? If you do, it is made of silver. You can turn that coin into a nice silver band using a spoon, a drill, and a metal file.
A quarter will yield a small ring, size ~7 or less. You can get a larger size but the ring will be very skinny. If you want a larger size ring, a Kennedy half dollar will work well. Again, anything 1964 and earlier will be silver.