The Moon Crystals are a special kind of crystal that made their debut in The Cosmic Crystals III: The End of the Star World. There are 3 in existance, and these crystals along with the Cosmic Crystals, Light Crystals and Star Crystals are needed to open the way to Cosmitalitopia, the city at the end of the Star World. They provide power to Lonar, the strongest of the nine Lanu Spirits.
Moon Crystals are found in each of the 3 slides:
- Castle Secret Slide
- Cool Cool Mountain Slide
- Tall Tall Mountain Slide
The crystals helped keep the Star World's clock combination, but when they were collected, the combination was gone. Rocko called his "Star World Friends" to turn the clock out of control to keep out trespassers.
- In the beginning of The Cosmic Crystals 3, Mario went on all the Mushroom Kingdom Slides before Stario sending them the message.
- They are the Star World Counterpart of Shine Sprites.