Super Gem

Diamonds are collectible items in the upcoming game Captain Toad: Treasure Tracker. They serve the same purpose as Green Stars in Super Mario 3D World, Star Coins in the New Super Mario Bros. series and Star Medals in Super Mario 3D Land and like said games, they are scattered around on the stage, and sometimes a certain puzzle met be done to collect them. Like Super Mario 3D Land, they are used to unlock some levels.