Gratitude Crystals are feelings of gratitude and happiness compressed into a crystal. Link is asked by the demon Batreaux to collect these so he can become a human. The more Link collects, the more prizes he receives from Batreaux. Prizes include bigger wallets, a Piece of Heart, and the Cursed Medal. In addition, Gratitude Crystals can be received by completing side quests.
- ↑ "Crystallized feelings of pure gratitude. Gather them and show them to Batreaux." — Collection Screen Description, Skyward Sword.
- ↑ "You got five Gratitude Crystals! These crystals are feelings of gratitude in crystallized form. It must have taken a lot of gratitude to produce this bunch of five crystals! Helping people feels good!" — In-Game Description, Skyward Sword.
- ↑ "You got one Gratitude Crystal! These form when a person is so completely overwhelmed with feelings of thankfulness that crystallized gratitude is created. Collect these and show them to Batreaux!" — In-Game Description, Skyward Sword.
- ↑ "It seems that when humans make other humans happy, the happy humans produce a substance known as a Gratitude Crystal." — Batreaux, Skyward Sword.
- ↑ "His name is Batreaux, and he is a kind- hearted person. All the Gratitude Crystals that you collected helped him turn from a demon into a human. But he still has an innocent heart, which endears him to children." — Fi, Skyward Sword.
- ↑ "Batreaux would like you to collect Gratitude Crystals and wants to see them for himself so that he can become a human. If you aid him in this search, Master, there is an 85% probability that it will benefit you as well." — Fi, Skyward Sword.
- ↑ "You collected enough Gratitude Crystals for Batreaux to become a human. I estimate a 60% chance that the Skyloft-demon rumor will die. But there is still a 40% probability that the rumor will not fade, based upon the possibility that people will still find Batreaux's new human face terrifying." — Fi, Skyward Sword.