In Pokémon Black and White, you can find Fire Stones in Dust clouds that will materialize in Twist Mountain, Victory Road, Giant Chasm, Challenger's Cave, Wellspring Cave, Chargestone Cave and Mistralton Cave. Additionally you can find one in the Desert Resort and you can find an extra one from the guy in Castelia City in the event of answering Pansear to his question.
in pokemon black and white
Pansear evolves by Fire Stone into Simisear.
it is in the desert near relic castle
Petilil will evolve with a sun stone, pansage with a leaf stone, panpour with a water stone, and pansear will evolve with a fire stone.
Pansear uses a fire stone to evolve into Simisear.
Castelia city just as you go into it after the bridge from Pinwheel Forest
So far (although I have completed White not yet Black) all I know are Pansage (Leaf Stone), Pansear (Fire Stone) and Panpour (Water Stone). Sorry if this isn't as helpful as you hoped!
Fire stone evolves Pansear into Simisear.
pansear
You get the fire stone on the first dock of castelia city.
pansear the fire monkey pokemon
i hear u need to go around and ask people