To answer this:
- I think, repeat, think I might've found an Everstone, but I'm not sure.
I found an everstone on the Dangoro (Roggenrola) that I caught at level 11 in the cave on Route 3. Imagine my surprise when I found it holding it when it grew to level 26 without evolving.
I've found gems before, but not stones. Oh, and lots of Drilbur and Excadrill.