Lead Bar

Worlds roll either this or iron, and the gear made from each sits close enough together that no build cares which one you got. The anvil, the buckets, the chains and the early tools all exist on both sides, so there is nothing to chase across worlds and no reason to feel short changed.

A new Journey character always starts with the iron versions of the starter tools, even in a world that generated with lead. It costs you nothing, but the very first pickaxe you own will not match the rest of your inventory.

Actual lead is soft and heavy, which would make it a poor thing to build armor out of, and it is a neurotoxin, so a cooking pot made from it reads as a joke the game did not intend.