From Bulbapedia, the community-driven Pokémon encyclopedia.
Several types of jewelry have been manufactured with the likenesses of Pokémon characters. In general, most types of Pokémon jewelry manufactured have been intended for wear by children, although a few pieces, namely wristwatches, have been designed for adults.
A Pokémon Dog Tag featuring Meowth
Pokémon Collectible Dog Tags
A series of collectible dog tag-style necklaces was manufactured with the likenesses of Pokémon characters in 1999 by Toy Site. Each necklace came with two dog tags - one with the Pokémon logo and one with a Pokémon on it. There were ten available Pokémon: Pikachu, Beedrill, Meowth, Gengar, Snorlax, Pidgeot, Charizard, Blastoise, Poliwrath and Venusaur.
Birthday cake rings
A series of rings were made by Bakery Crafts in 1999. These rings were designed so that they could be used as decorations for a birthday cake as well as wearable jewelry, so that guests could each take one ring home.
The 10th Anniversary Pikachu watch
10th Anniversary Pikachu Fossil watch
A limited edition analog wristwatch featuring Pikachu was issued by Fossil in 2006 in celebration of Pokémon's 10th Anniversary. It was available at Pokémon Center's online store. Only 1500 of these watches were made.
Life cereal watch
In 1999, Life cereal offered a digital wristwatch featuring Ash, Misty and Brock in exchange for coupons collected on cereal boxes.
A digital wristwatch featuring Mewtwo was made by Innovative Time Corporation in 2000. The watch featured two changeable wristbands (one with the Pokémon logo and one with artwork of Mewtwo) and an image of Mewtwo on a cover which, when lifted, would reveal the time on a digital clock.