Lets be comically brutal here
The early mine edit2 is a step back from the vanilla mine icon imo, last thing I want in a sedentary era mine icon is something that looks like it belongs on a street sign.
A is too washed out, that glare ruins it and I'm not sure what I can say about C, it looks more Pokemon than mining icon.
I like B, the Tonka Truck one, it's a good compromise between my vision of a modern strip mine and your insistence that subway stations make perfectly fine locations to dig for ore.
Btw while we are at it, what about the beacon and light house improvements having the same icon? We could start branching off trying to bottonize new lighthouse designs, I'll suss around about that tomorrow.
Oh btw, looking at the core mine icon and I really do not like it, looks more like a marble cutting quarry.
Another thought came to mind that the edit 2 early mine reminded me of, I hate the geology icon! If anything should be its icon, it's that effing jewelers loop they carry with them always, cause with geologists, you never know when they might run into some interesting rock formations.
Cheers!
-Liq