In Gold? Only through Bill's Grandpa in Cerulean (Show him a Pichu), and via Mystery Gift. Or, if you have one on another version, attach it to a PKMN and trade it over.
In Crystal, there's a trainer whose number you can get (can't remember who, but I think they're just west of Ecruteak...?). Every once in a while they'll call you and say they have a gift, which turns out to be a Thunder Stone (Also works with the other Elemental Stones)
Leaf Stone- Picnicker Gina (route below goldenrod) Fire Stone- Schoolboy Alan (route east of national park) Thunderstone- I'm almost positive this one is between ecruteak and olivine, but I can't remember exactly who it is. Lass Dana maybe? Water Stone- Fisher Chris, directly west of Mahogany Town.
TheMusicMan on NB and virtually everywhere else. Pearl FC: 0430 5967 9253
you should add that they can be atached to one Pkmn, and if you clone the Pkmn correctly, you duplicate the item
let me see, that would mean that, other than getting it through Mystery Gift (where they are rare items) you would need to "clone" the Leaf Stone at least 2 times (you need it for Exeggutor, Vileplume and Victreebel), the Fire Stone 1 time (you need it for Ninetales and Arcnine), the Thunderstone 1 time (you need it for Raichu and Jolteon), the Water Stone 3 times (you need it for Poliwrath, Cloyster, Starmie and Vaporeon)
you need more than 1 King's Rock, but you can get others because Poliwhirl, Slowpoke and Slowbro may rarely be holding one. Metal Coat can rarely be found attached to Magnemites, and Dragon Scales to Dratini, Dragonair, Horsea or Seadra
Pokémon Master: I'm in the No-Breed Group... mess with me at your own risk! The sum of the intelligence on the planet is a constant; the population is growing!