Year 17: The Thaldrin tribe had a skirmish during a hunting trip with the wolf tribe and discovered their use of copper in clubs. Year 19: The Thaldrin tribe figured out how to mold copper into useful weapons, tipped a spear with bulbous bulbs, and created the first Shalth weapon.
The Chalcotholic period is where copper metalworking became common and useful. Tribes can now form copper weapons, shields, armor, stronger buildings, and can begin to build countries instead of just tribes.