I have 2 ideas how panning would work.
Idea 1 is like a small minigame. You see a yellow circle in the middle of your screen, and you have to move your mouse around it like you are sifting the pan. If you stray outside the circle you will have less metal in the end, and if you go inside the circle that revolution will not count. Once 30 revolutions are made, the minigame is done. The longer it took for you to do it, the more metal you get. The quality is governed by dexterity. There is "copper dust", "gold dust", "iron dust", and so forth. With 10 of any of them you get one nugget when they are placed in an ore smelter.
Idea 2 is just that little progress bar and everything is random. I like idea 1 better.
The metals you get is decided by chance, but if there is a mine in the same region as you, that metal has a better chance. Just an idea. And yes, I have panned for metals before, and succeeded at finding gold. I am educated in this manner.
