In the core series games, if an Eevee is leveled up in an area containing an Ice Rock, it will evolve into Glaceon. Even if Eevee meets other evolutionary conditions when leveled up, the Ice Rock will still cause it to evolve into Glaceon rather than Espeon, Umbreon, or Sylveon. In Generation VIII, this mechanic was replaced by using an Ice Stone to evolve Eevee into Glaceon.
In the core series games
- In Sinnoh, an Ice Rock is located a short way south from Snowpoint City on Route 217. It is located in an area where the blizzard is very rough, on the easternmost part of the route. It actually appears that the rock is located in the backyard of a house that is near a female Skier. It is surrounded by long grass.
- In Unova, an Ice Rock is located in the basement of Twist Mountain, just west of Icirrus City. It is located on the lowest floor, past an NPC who gives the player Fossils of previous regions. Eevee must be leveled up in the room with the Ice Rock in order to evolve into Glaceon; it will not evolve into Glaceon by leveling up anywhere else in Twist Mountain.
- In Kalos, an Ice Rock is located deep within Frost Cavern. Surf is required to access it.
- In HoennORAS, an Ice Rock is located on the lowest floor of Shoal Cave, accessible only when the tide is low.
- In Alola, an Ice Rock is located inside the cave in Mount Lanakila.
As the Ice Rock is not present in HeartGold and SoulSilver, Eevee cannot evolve into Glaceon at all. The only way to obtain Glaceon in these games is to get it from a trade from one of the other Generation IV games, Diamond, Pearl, and Platinum.
In spin-off games
Due to the Ice Rock's absence in Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness, Eevee evolves into Glaceon through the use of the Frozen Rock, and the same method in Gates to Infinity.
In Pokémon Conquest
In the anime
An Ice Rock appeared in a flashback in A Full Course Tag Battle!, where it was revealed that May had visited it in a cave near Snowpoint City in order to evolve her Eevee. Unlike the games, where an Eevee must be leveled up but can be anywhere in the area housing the Ice Rock, May's Eevee promptly evolved into a Glaceon upon touching the Ice Rock, much like an Evolution stone.