On the left is a 1961-D Lincoln cent that appears to be struck on a silver planchet. (Or another metal - though I don't know what it could have been from 1961.) On the right, is a 1919 Lincoln cent that is in AU condition and retained a good amount of its luster.
Found this duo in my silver stash.
Don't let the designs fool you, these are silver bullion coins that are modeled after Morgan and Peace dollars. The rainbow toning on the Morgan-esque bullion coin is quite attractive.