What is a Diamond? EditDiamonds are currently used to purchase different character skins, additional player-owned store slots and also for changing your character's name.
Diamonds are bought from the in-game store with real-world currency and they can be bought from players in-game for around 4000-6000 Coins each. The prize of diamonds still climb higher so this prize is middle of every prize in game.
Note: You can't get diamonds for free with lucky patcher, so don't try.