How do you get a firestone in poemon leafgreen?

You can't get a Firestone in Pokemon LeafGreen. Firestone is an item introduced in Pokemon Diamond and Pearl, and it's used to evolve certain Pokemon.

However, in LeafGreen, you can get a Fire Stone which is used to evolve Eevee into Flareon. Here's how you can get one:

* Celadon Department Store: You can buy a Fire Stone from the 2nd floor of the Celadon Department Store for 3000 Pokedollars.

* Trade: You can trade with other players to get a Fire Stone.

* Find one in the wild: Fire Stones are extremely rare, but there is a small chance you might find one in the wild.

Remember, you can't evolve a Pokemon like Growlithe into Arcanine using a Fire Stone in LeafGreen. Those evolutions are done through trading with specific evolution stones.