In the core series games
If held by an Altaria, allows it to Mega Evolve into Mega Altaria 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 Altaria an Altarianite or remove an Altarianite from Altaria.
Outside of battle
If held by an Altaria, allows it to Mega Evolve into Mega Altaria when it performs a Spectacular Talent during a Pokémon Contest Spectacular while its Trainer has a Key Stone. Altaria will remain a Mega Altaria until the Talent Round ends.
Pokémon holding Altarianite in Pokémon Omega Ruby and Alpha Sapphire cannot be traded to Pokémon X and Y.
| One of a variety of mysterious Mega Stones. Have Altaria hold it, and this stone will enable it to Mega Evolve during battle.
In spin-off games
|| This section is incomplete.|
Please feel free to edit this section to add missing information and complete it.
In Pokémon Shuffle, the Altarianite allows the player to Mega Evolve Altaria.
The player can obtain the Altarianite by defeating Mega Altaria in Stage 75 found on Galerie Rouge.
The Altarianite enables the following Mega Evolution:
|| Mega Altaria
|| Erases all Pokémon within two spaces of the match.
If more icons of this Pokémon are adjacent to the match, then for each additional icon, one more Pokémon is erased in that direction.
In other languages
|| 七夕青鳥進化石 Chātjihkchēngníuh Jeunfa Sehk
|| 七夕青鳥進化石 / 七夕青鸟进化石 Qīxìqīngniǎo Jìnhuà Shí
|| 파비코리나이트 Pavicorinite