Eviolite is an item in the “Held items” category (Items). It costs ₽4000.
In-game descriptions
| Black / White · Black 2 / White 2 | A mysterious evolutionary lump. When held, it raises the Defense and Sp. Def of a Pokémon that can still evolve. |
|---|---|
| X / Y · Sun / Moon · Ultra Sun / Ultra Moon | A mysterious Evolutionary lump. When held by a Pokémon that can still evolve, it raises both Defense and Sp. Def. |
| Let’s Go, Pikachu! / Let’s Go, Eevee! · Sword / Shield | A mysterious evolutionary lump. When held by a Pokémon that can still evolve, it raises both Defense and Sp. Def. |
Where to find it
Not placed on the atlas maps (so far: Red/Blue and Generation 3).
Sources : PokeAPI (items, item_flavor_text, machines) · atlas · pokeemerald species_info.h