[No, no. Abbey clarifies: it's not her problem, it's Rubin's. He eats rocks and stuff. That's why Rin won't let him out of the pokeball. And then she whispers conspiratorially: Don't tell anyone, but he chewed on the really big rock in the middle of the room.]

I think it could be fun, at least. Barring gems, it'd be amazing to find a fossil like the ones mentioned in this museum.

That's actually what leads me to believe there's a decent chance of finding the odd precious gem in the mines. Many diamonds are prehistoric, just like fossils. Either one would be a great find.