Mesmerizing. There's a bunch of YouTube vids where people completely change the character of coins (Hobo I think they are called). A lot of coins are softer so they can get away with non powered engraving tools, but I would think it would be even more challenging. Literally carving metal. There was a guy at the fall metal artisan show (or whatever they called it) at Reynolds Museum weekend show & he had a computer screen hooked up to his magnifying computer display so you could see what was happening. Very cool.