Diamond

Diamonds are rare they can be found under ground or in the store diamonds can be useful because you can make the most powerful tools out of them for example a diamond axe. and they can be used to make the most powerful armor diamond are useful is what i'm trying to say there so let's just say that a friend decides to troll you with a hoard of zombies well with a diamond sword  you can easily slice and dice those zombies to find diamonds where you need to go is underground or you can craft diamonds using a crafting table just make sure you have a diamond block because to craft a diamond you will need a diamond block and that'sall.