been working on a ring as a mother's day gift. it takes a hard surface, a good steel spoon, and a whole lot of patience. you'll need to find a quarter from 1964 or earlier, back when they were 90% silver. today's quarters use more nickel and copper, which will turn your skin all kinds of colors.
you can usually find some good coins on ebay for about $3.50 each (the going rate for that amount of silver)
not done yet, but i'll post the final photos.