Because you didn't specify, I'll just answer for all the games.
- Gold & Silver: Azalea Town
- Crystal: Azalea Town, Ruins of Alph
- Ruby, Sapphire, Emerald: Lavaridge Town
- FireRed & LeafGreen: Rocket Game Corner
- Colosseum: Held by shadow Quilava
- XD: Held by shadow Numel
- Diamond, Pearl, Platinum: Route 227
- HeartGold & SoulSilver: Azalea Town, Ruins of Alph
- Black & White: Nacrene City, Route 16
- Black2 & White2: Castelia City, Held by wild Torkoal (5% chance)
- Dream World: Rugged Mountain
- X & Y: Couriway Town, Held by wild Torkoal (5% chance)
- Omega Ruby & Alpha Sapphire: Lavaridge town, Held by wild Torkoal & Vulpix (5% chance each)
- Sun & Moon: Wela Volcano Park, Held by wild Torkoal & Turtonator (5% chance each)
Hope this answers your question adequately! Source
