From Bulbapedia, the community-driven Pokémon encyclopedia.
Volcanic ash (Japanese: かざんばい Volcanic ash) is a raw material used to make items at the Glass Workshop on Route 113 in Pokémon Ruby, Sapphire, and Emerald and Pokémon Omega Ruby and Alpha Sapphire. Ash can be made into either flutes or furniture. The furniture will be sent directly to the PC and can be used to decorate a Secret Base. Ash can be collected on Route 113 and Jagged Pass, where it settles from Mt. Chimney. In order to collect ash, the player must first obtain the Soot Sack.
In Pokémon Ruby, Sapphire, and Emerald, ash is collected by walking through ash-covered tall grass. The grass will have a gray appearance if there is still ash on it, and after the player walks through it, it will turn green. The amount of ash collected is counted by the number of steps the player has walked through ash-covered grass..
In Pokémon Omega Ruby and Alpha Sapphire, ash is collected by walking through soot piles. All soot piles provide random amounts of ash, in either a small amount (approximately 5 to 15 grams) or a large amount (approximately 30 to 60 grams). The visual and sound effects produced when scattering soot piles differs slightly depending on whether they provide a small or large amount of ash. Roughly 1 in 5 soot piles provide a large amount of ash.
