How to Get Thunder Stones on "Pokemon Emerald"by Matt Koble ; Updated September 22, 2017
Electric Pokemon are the bane of Flying and Water type monsters everywhere, and "Pokemon Emerald" has no shortage of options for fans of electricity. The Thunder Stone item evolves compatible Pokemon into their stronger Electric-type forms, making these stones essential for "catchin' 'em all." While the game features three Thunder Stones, only two Pokemon use them, and you may not want to use the stone the second you get it.
"Pokemon Emerald" houses a Thunder Stone in the New Mauville power plant. To access the plant, you'll need the HM move Surf and a Pokemon who knows it. You'll also need to get the Basement key from Watson where Route 110 meets Route 118. Access the plant via Route 110, surfing east and under the bridge to an island with a cave. You'll find the power plant inside the cave. The Thunder Stone is in a Pokeball in the final room, with the generator.
Once you know both the Surf and Dive HM moves, you can obtain two Yellow Shards. Give the Yellow Shards to the Diving Treasure Hunter in his house on Route 124 and he'll give you a Thunder Stone for each. Find one inside a Pokeball on an island in the Northeast corner of Route 124. You'll find another hidden in seaweed while diving on route 126. Use the Itemfinder to aid you in your search.
Chinchou and Lanturn
Two wild Pokemon -- Chinchou and Lanturn -- also sometimes hold Yellow Shards. Every time you encounter one in the wild, there's a 5% chance it's holding a Yellow Shard. Both Pokemon are only found underwater while using Dive. Increase your chances of finding a Shard by repeatedly catching multiple Chinchou or Lanturns, then checking them for the held item you seek.
While you can obtain many Thunder Stones in "Pokemon Emerald," only two Pokemon native to the game use this stone to evolve. Use a Thunder Stone on Pikachu to evolve him into Raichu. Using a Thunder Stone on Eevee makes him evolve into the Electric Pokemon Jolteon.
When to Use
The obvious advantage to using your newly acquired Thunder Stone is to evolve your Pokemon, but waiting can prove rewarding. Some Pokemon -- including Pikachu -- don't learn many or any new moves after evolution. At level 26, he learns Thunderbolt and at level 41 he learns Thunder, two powerful Electric-type moves. Raichu, on the other hand, does not learn any moves by leveling up. Jolteon is a different story. Eevee is a Normal type Pokemon, and learns mostly Normal type moves as he levels up. Once you evolve him into Jolteon, he'll learn a number of new Electric moves, including Thunder Shock, Thunder Wave and Thunder, as well as a number of non-Electric moves.
- link Bulbapedia: New Mauville
- link YouTube: Pokemon Emerald Water/Fire/Thunder/Leaf Stones Walkthrough
- link PKMN: Yellow Shards in Emerald
- link Bulbapedia: Hoenn Route 124
- link Bulbapedia: Hoenn Route 126
- link Bulbapedia: List of Pokemon by Wild Held Items
- link Bulbapedia: Chinchou
- link Serebii: Thunderstone
- link Pokemon DB: Pikachu - Generation 3 Learnset
- link Pokemon DB: Raichu - Generation 3 Learnset