Question: pokemon let's go pikachu how to get fire stone?
Answer: You can pick up a free Fire Stone on Route 8 and in the Pokemon Mansion.
Otherwise, you can buy a Fire Stone on the 4th floor of Celadon City's mall for 5000 Poke Dollars.
The fire stone evolves Vulpix into Ninetales, Growlithe into Arcanine and Eevee into Flareon.