Not sure if this was already asked, as I couldn't find it when I was looking for it. I really need one to evolve a certain Pokémon(Eevee). If anyone has any good info, that would greatly be appreciated.
Thunderstones in Pokemon X can be found in the following locations:
Route 18
Or if you're willing to do some super training in the bottom menu, you can get thunderstones from a mission there.
Source: Serebii. Good luck!
