Rare Earth Metals
This was an idea that I had a while back for a different type of resource progression. "Rare Earth Metals" would be one resource lumping together elements like lithium, cobalt, etc., obtained exclusively through excavation— which should ideally be fixed for double-digging before then— or random meteorite events which would spawn metal deposits on the surface. To compensate for the exclusively manual means of obtaining this resource, Rare Earth Metals would mostly be used for building structures and vehicles instead of being passively consumed or converted into other resources (very realistic ik). Rare Earth Metals would be required in exceedingly large amounts for certain late-game structures, incentivizing trading and manual gameplay beyond selecting build points in the late-game as we know it. uh hopefully this doesn't end up like obsidian in mc1 did
I haven't made an icon for the resource itself, but I've made a couple of concept models for Rare Earth Metal deposits and a harvester. Let me know what you think of them and the overall idea!
Rare Earth Extractor

An advanced harvester designed to filter every last bit of rare metal out of the surrounding rock.
Rare Earth Metal Meteoric Deposits

These deposits are quite small in both size and resource yield; maybe like 250 units of rare earth metal for the smallest one and 750 at most for the largest.