Stat-enhancing item

Stat-enhancing items are held items that affect a particular stat of a Pokémon. These items have effects only when used on certain species of Pokémon and will have no effect on any others.

Artwork
These are artwork of the items as seen in the Pokémon Dream World.

In the anime
A Deep Sea Tooth and a Deep Sea Scale appeared in The Evolutionary War. They were used to evolve and Nancy's  into a  and a, respectively.

A Stick, two Deep Sea Teeth, two Deep Sea Scales, and a Thick Club appeared in Showdown At Linoone as some of the items.

The Soul Dew appeared in Pokémon Heroes: Latios & Latias, where it was used to power up the Defense Mechanism of Alto Mare.

Trivia

 * The Rare Bone and Thick Club share the same Bag sprite.
 * Because cannot be found in the wild in Unova,  and similar moves no longer permanently steal items held by trained Pokémon, and Poké Transfer prohibits the import of held items, the Light Ball cannot be obtained in Generation V outside of events.
 * Because of changes to critical hits in Generation VI, will always get a critical hit when using moves with a boosted critical hit ratio and holding the Stick.
 * Eviolite's Japanese name contains a pun; しんかのきせき Shinka no Kiseki can also be taken to mean "Miracle of Evolution".