A Water Stone is a special type of evolutionary item in the Pokémon video game series. When certain water-type Pokémon are exposed to this stone, they can evolve into a more powerful form. This item is often found in various locations throughout the games, such as caves or by the sea. In addition to its use in Pokémon evolution, the Water Stone is also a popular item among collectors and fans of the franchise. It is one of several elemental stones, each associated with different types of Pokémon, including Fire Stone and Leaf Stone.