Go To Castellia city go all the way to the right unill you see the last stair and go down talk to the scientist he will ask which monkey did you get if you picked PANSEAR you will get a fire stone
pansear
Fire stone evolves Pansear into Simisear.
You give it a fire stone
in pokemon black and white
in white two, you can find it in the desert resort
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.
it is in the desert near relic castle
Pansear evolves by Fire Stone into Simisear.
it evolves with a fire stone not by leveling up
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!
how should i no
A fire stone is used on certain Pokemon to make them evolve. The Pokemon that evolve with a fire stone are: ~Evee ~Vulpix ~Growlithe