While it is possible to obtain other evolution stones like the Fire Stone, Water Stone, and Thunder Stone, the Leaf Stone is not available in the game. This means you can't evolve Pokémon like Gloom into Vileplume or Weepinbell into Victreebel in Shiny Gold.
If you're looking to evolve these Pokémon, you'll need to play a different version of the game where the Leaf Stone is available, such as Pokémon Gold or Silver.