Actually, you can scratch pure gold with your nail. Take into account that the hardest substance in the human body is the enamel, if you're careful and have strong teeth, you actually can bite that leek in half.
ThunderBird said: Actually, you can scratch pure gold with your nail.
You can leave fingerprints in it with a light press. My gold-plated Pikachu card has one thanks to my dumbass Aunt feeling such a need to touch it that she pried it out of the protective case to poke it while I wasn't looking.