Right?

"Early metallurgists found to have been experimenting with the properties of metals and ores, laying the foundation for future advances that would prove economically and technologically important" is not the biggest possible reveal.

To be clear, I'm not dismissing the research, which seems to be more about how they discovered it. I can understand if that was/is an open question, and these possible answers are pretty interesting. I was just wondering if there were competing theories here with reasons to doubt one is more likely than the other.

Many years ago, my roommate was working on his PhD in geology while my history obsession was in full bloom and we talked about this a little. He made some interesting points about iron versus copper supply and how its relative abundance meant that some cultures would have had access to iron long before access to copper.

The transition to iron was very slow and some places kept using bronze for centuries. There’s also no single point (known) for where the Iron Age started. In Nigeria, for example, it seems most likely that Nok people worked with iron first and had no significant Copper or Bronze Age.

I think that the closest answer is that we don’t know for sure, but evidence seems to show that the path to iron followed different paths in different parts of the world. In some cases, the copper industry would have been heavily involved. In other places, an iron industry seemed to take shape before a copper industry, so the developments would have been independent.

Interesting, thank you! I would have expected the higher melting point of iron to be a big hindrance compared to copper (and other metals), but hadn't considered the possibility of copper just not being locally present for some ancient cultures.