If held by a Gardevoir, allows it to Mega Evolve into Mega Gardevoir if its Trainer has a Key Stone. Each Trainer can only Mega Evolve one Pokémon per battle.
Unaffected by item negating effects (such as Embargo and Klutz). Item manipulating effects (such as Trick and Fling) cannot give Gardevoir a Gardevoirite or remove a Gardevoirite from Gardevoir.
Outside of battle
If held by a Gardevoir, allows it to Mega Evolve into Mega Gardevoir when it performs a Spectacular Talent during a Pokémon Contest Spectacular while its Trainer has a Key Stone. Gardevoir will remain a Mega Gardevoir until the Talent Round ends.
The player can obtain the Gardevoirite by finishing the competitive stage available in Week 21 of the event rotation or by reaching Trainer Rank 20.
The Gardevoirite was also available as a prize during the Mega Gardevoir competitive stage. This competitive stage ran on the Nintendo 3DS version from November 2 to 9, 2015; June 14 to 21, 2016; February 14 to 20, 2017; and December 5 to 12, 2017. It ran on the Pokémon Shuffle Mobile from June 14 to 21, 2016; February 14 to 20, 2017; and December 5 to 12, 2017.
The Gardevoirite enables the following Mega Evolutions:
In PS616, the Meteor Villageelder offered Sapphire a Gardevoirite and Galladite, commenting on how her Gallade and Ruby's Gardevoir are a match. Ruby and Sapphire later used these Mega Stones to Mega Evolve Rara and Kirly during a brief battle against each other.
