| IMPORTANT ITEM|
|Description||The very un-red-herring real thing from Poshley Sanctum.|
|Use||Used for opening The Thousand-Year Door, reveals the next Crystal Star, and defeat the Shadow Queen|
|To||Thousand-Year Door Pedestal|
|Other Edition||Unknown edit|
The Garnet Star, was created by the Shadow Queen as apowerful object that could be used to rule the world along with the other Crystal Stars. It somehow ended up in Poshley Sanctum, a shrine to the stars, and the rumour of treasure in the Poshley Sanctum soon spread. However, the star in the antechamber of the sanctum was a red herring to counter thieves. In his quest for the Crystal Stars, Mario was alerted to the Star's whereabouts, by the Sapphire Star. Professor Frankly assured him that getting this star would be easy and Mario obtained a ticket for the Excess Express from Don Pianta. The train ride was full of troubles and mishaps, but Mario eventually got to Poshley Heights He went to the Sanctum only to watch the Shadow Sirens steal the Star! However, they had fallen for a red herring. Mario found his way into the back, claimed the real Garnet Star, and then took it to the Thousand-Year Door. It glowed brightly and revealed the location of the final Crystal Star, the Moon!
After Mario obtains the Garnet Star, more powers become available to him. His Star Power increases from six to seven and he learns the special move Showstopper.
| Diamond Star | Emerald Star | Gold Star |
Ruby Star | Sapphire Star | Garnet Star