- For which Pokémon evolve from which Evolutionary Stones, see List of Pokémon that evolve by Evolutionary Stone.

A set of Evolutionary Stones in "Mystery on a Deserted Island!"
Evolutionary Stones are a type of evolution item introduced in Generation I.
Description

Concept art of a Water, Fire, and Leaf Stone
There are several types of Evolutionary Stones, each having the power of a certain type of element that instantly evolve certain species of Pokémon by exposing them to it.
There is a type of stone named the Everstone that negates the effects of an Evolutionary Stone. Although the Everstone could be considered the functional opposite of an Evolutionary Stone directly, it prevents any Pokémon from evolving, regardless of their evolutionary method.
Types
A few of the Evolutionary Stones are associated with a certain type, including the Fire Stone with Fire, the Water Stone with Water, the Leaf Stone with Grass, the Thunder Stone with Electric, the Dusk Stone with Ghost and Dark, and the Ice Stone with Ice. Contrarily, a few types of Evolutionary Stones are not linked to a type: the Moon Stone, which is linked to the moon; the Sun Stone, which is linked to the sun; the Shiny Stone, which has a dazzling appearance; and the Dawn Stone, which only evolves certain species of Pokémon of a certain gender.
There are ten types of Evolutionary Stones in total. The first five Evolutionary Stones were introduced in Generation I: the Fire Stone, Water Stone, Leaf Stone, Thunder Stone, and Moon Stone. Generation II introduces a sixth type, the Sun Stone. Generation IV introduces three more types: the Shiny Stone, Dusk Stone, and Dawn Stone. Generation VII introduces the tenth type, the Ice Stone.
Pokémon
Only two Pokémon species have branched evolutionary lines that depend solely on which Evolutionary Stone is given to them. Of the two, Eevee is the most notable for having an evolved form regardless of the Evolutionary Stone used on it, known as the Eeveelutions. The other Pokémon is Gloom, which evolves into Vileplume from using the Leaf Stone or into Bellossom from using the Sun Stone, the latter as of Generation II.
Of all Pokémon who can evolve via Evolutionary Stone, only four of them (excluding regional forms) have alternate evolved forms: Poliwhirl, Eevee, Kirlia, and Snorunt.
Generation VII and Generation VIII are the only generations to not introduce Pokémon species that evolve via Evolutionary Stones, excluding regional forms. However, Generation VIII is the first generation to change a Pokémon's evolution method to Evolutionary Stones, as Moss Rocks, Ice Rocks, and special magnetic fields were scrapped in favor of requiring certain Evolutionary Stones.
The Leaf Stone and Thunder Stone can evolve the most Pokémon species, with a total of seven each (eight if counting regional forms). Meanwhile, Dawn Stone has the fewest, with only two.
Appearances
Core series
In every game in the core series, an Evolutionary Stone can be used by selecting it from the Bag and then which Pokémon in the party to apply it to. Without trading, using Evolutionary Stones on certain species of Pokémon is one of many requirements to filling the Pokédex. Despite their essential role, Evolutionary Stones are not key items and disappear after single use.
The Evolutionary Stones within the Generation I games can all be bought at the Celadon Department Store, except the Moon Stone, which appears in various locations.
Spinoffs
Pokémon XD: Gale of Darkness
In Pokémon XD: Gale of Darkness, the Sun Shard and Moon Shard take role of the Sun Stone and Moon Stone, respectively; a happy Eevee can evolve into Espeon with a Sun Shard or Umbreon with a Moon Shard.
Pokémon Mystery Dungeon series
In Pokémon Mystery Dungeon: Red Rescue Team and Pokémon Mystery Dungeon: Blue Rescue Team and the remake Pokémon Mystery Dungeon: Rescue Team DX, after clearing the game, the player can go to Luminous Cave to evolve Pokémon, including species that evolve through Evolutionary Stones.
Pokémon GO
The only Evolutionary Stone that returns in Pokémon GO is the Sun Stone, although the game adds two unique types: the Sinnoh Stone, which evolves certain Generation IV Pokémon, and the Unova Stone, which evolves certain Generation V Pokémon. Besides an Evolutionary Stone, each Pokémon that evolves through the method requires a certain amount of Candy.
Pokémon Sleep
Every Evolutionary Stone appears in Pokémon Sleep except the Sun Stone and the Dusk Stone. Evolutionary Stones are used to evolve certain Pokémon species, but Candy is also required, similar to Pokémon GO. However, eighty candy must be used from the evolutionary family of the species that the player wants to evolve.
Anime
Evolutionary Stones have appeared through the anime and function identically to their appearance in the core series. The first Evolutionary Stone to ever appear is the Moon Stone, in "Clefairy and the Moon Stone".
In "Whichever Way the Wind Blows", which features several Vileplume and Bellossom, the Leaf Stone and Sun Stone are in a visual explanation showing how they evolve Gloom into Vileplume and Bellossom, respectively.
While most episodes feature only one type of Evolutionary Stone, "Mystery on a Deserted Island!" includes every type except the Ice Stone, which had not been introduced yet when the episode premiered. Many Eevees use the Evolutionary Stones to become their Eeveelutions.
Manga
Pokémon Adventures
In Pokémon Adventures, Evolutionary Stones are depicted with the symbol of their corresponding type, but they still retain their usual function.
Pokémon Pocket Monsters
In Pokémon Pocket Monsters, Evolutionary Stones are mostly the same, though the seventeenth chapter shows a Jolteon switching between Flareon and Vaporeon as Red throws Fire Stones and Water Stones, respectively.
Trivia
- There is a real jewelry rock called moonstone, and it is unknown if the Moon Stone item is just an uncut and unpolished moonstone. Sun Stones are similar, with the same ambiguity.
- The evolved forms tend to have dramatically different level-up learnsets, with the majority of these learning no new moves at all, such as Togekiss and Roserade. A notable exception is Sunflora, which has a roughly identical learnset from leveling up as Sunkern.
- During the development of the Generation II games there was going to be a new stone called the Poison Stone, which was the beta form to evolve Eevee into Umbreon (Umbreon was going to be Poison type during the development) and Weepinbell into a new form (which was later discarded) but the poison stone was discarded in the final games for unknown reasons.