The Crystal Star is the last of all the "Crystal Stars" you collect in Paper Mario: The Thousand-Year Door. While all the other Crystal Stars are made of different types of stone, this star in particular is actually made of Crystal. Mario finds it on the Moon in the X-Naut Fortress, heavily guarded by Yuxes and X-Nauts alike. He is challenged by Lord Crump for it, who summons his brand new weapon, Magnus Von Grapple 2.0. It gives you the SP move Supernova, the strongest SP move.

Crystal Stars
Diamond Star | Emerald Star | Gold Star
Ruby Star | Sapphire Star | Garnet Star
Crystal Star