For Galena specifically: look for Hydrothermal geology. Before core drilling it appears on the map as a rust-brown field, #9E5C38. Once revealed, Galena itself is a blue-grey, about #5C616B.
| In-game geology name |
Pre-core map colour |
What the Core Drill can reveal |
| Sedimentary geology |
Tan/brown #9E8052 |
Gypsum, Apatite, Graphite, Pyrolusite |
| Hydrothermal geology |
Rust brown #9E5C38 |
Galena (Lead), Sphalerite (Zinc), Fluorite, Wolframite, Scheelite, Molybdenite, Native Gold, Argentite |
| Magmatic geology |
Charcoal #38383D |
Pentlandite (Nickel), Chromite, Ilmenite, Rutile |
| Lateritic geology |
Orange-red #B84C24 |
Bauxite, Kaolin |
| Evaporite geology |
Pale pink/beige #E0C7B8 |
Rock Salt, Borax, Sylvite |
| Pegmatite geology |
Pale lavender-grey #B8B8D1 |
Quartz, Cassiterite (Tin), Spodumene (Lithium), Bastnasite |
| Radioactive geology |
Green #4C852E |
Pitchblende, Monazite |
| Iron-bearing geology |
Red-brown #9E422E |
Hematite, Magnetite |
| Copper-bearing geology |
Green #389E52 |
Malachite, Chalcopyrite, Bornite |
| Coal-bearing geology |
Near-black #1F1F21 |
Coal |
| Limestone-bearing geology |
Beige/khaki #B8AD8F |
Limestone |
Important Galena detail
You actually have a much better chance of finding Galena closer to the starting area.
The Hydrothermal pool changes with distance:
Under 512 tiles from map origin:
Fluorite / Sphalerite / Galena
So Galena is effectively 1 of 3 Hydrothermal results.
At 512+ tiles, Wolframite, Scheelite and Molybdenite join:
Fluorite / Sphalerite / Galena / Wolframite / Scheelite / Molybdenite
So Galena drops to roughly 1 in 6.
At 640+, Argentite joins → roughly 1 in 7.
At 768+, Native Gold joins → roughly 1 in 8.
So if you've been travelling farther and farther away looking for lead, that has ironically been making Galena less likely.
For lead hunting right now, I'd specifically search the map for the rust-brown Hydrothermal geology fields inside roughly 512 tiles of the centre, then core drill those first.
One other potentially confusing design detail: some ores have a geological classification but do not roll from that generic family indication. For example, Chalcopyrite and Bornite are hydrothermal deposits internally, but they are deliberately removed from the generic Hydrothermal roll and put under Copper-bearing geology. Likewise Hematite/Magnetite use Iron-bearing, Malachite uses Copper-bearing, and Coal/Limestone have their own controls. That's why the table above is the useful actual gameplay spawn table, rather than merely the geological classification.