This is very niche and might be hard to implement into the game but instead of ores only being forged and refined I thought there can be a feature where ores have maybe an appraisal mechanic, which would be really sick. The rock can start off as un-appraised and be the normal value. With that, there can be an appraiser npc who appraises your rock, at a cost of course. The rock can be appraisd from a scale of 1-5(with 1 decimal place after so like 1.1 or 4.3) 5 being perfect and 1 being the worst. This should add a new rarity and collecting motive in ores rather than the boring gathering and selling. I think the 
appraisal can be on 3 factors. The size, the concentration(how many nodes of the mineral are on the rock), and just slight rng. This was heavily inspired from fisch because if it can be added into oaklands, it could be really cool to collect different grade rocks of different rarity.
#Ores appraisal/grading for rarity and higher costs
rare creek
Please feel free to discuss any possible additions to better this sugestion