Anyone know where I can source Reddish-brown cave rock or Volcanic rock besides in Rocky Ridges?

I'm not sure if Reddish-brown cave rock or Volcanic rock spawns anywhere else in the game, besides in Rocky Ridges, and I don't really want to mine it if it's not a renewable resource. Looking it up on Serebii, it only seems to be in Rocky Ridges, and not on any dream island. I even explored Arcanine's dream island to make sure. I'm okay with 3D printing the blocks, but I figured I'd ask first.