Yes you can you can find stones in dungeons or get them from rescue missions.
you cant srry.
Get A Thunder Stone! And Then Go Evolve it!
In Pokemon Mystery Dungeon: Explorers of Darkness, you can receive a Shiny Stone as a reward for completing certain missions or by finding it in certain dungeons. You can also sometimes receive a Shiny Stone as a gift from other Pokemon in the game.
you need a pichu and the wonder mail code you can get them off Pokemon websites
you need a wondermail mission to get it that's the only way ;D
you need a fire stone then you go to luminous spring and evolve
find a kecleon shop in mystifying forest that's how i got mine.
I think you need a thunder stone to evolve pikachu hope this helps you
In Pokemon Mystery Dungeon: Explorers of Time, Darkness, and Sky, players can obtain the Unown R Stone in Rock Aegis Cave by defeating a certain number of Unown in the dungeon. Keep exploring the dungeon, defeating Unown enemies, and eventually, you'll find the Unown R Stone as a reward for your efforts. Good luck!
It is in Final Maze 40F you need secret stone plate or enigma part in bag (secret slab or mystery part)
You can find one in blue rescue team by going to Lightning Field then go to the place to evolve with the stone.
You use it to get to Jirachi.