ironworking

I recently posted a thread asking why Native Americans never developed ironworking independently. Now I'd like to ask: what if they did?

As far as I know, Native Americans never independently developed ironworking. Why is that?

It is often said that African prehistory and antiquity, with the exception of Egypt, "went straight from the Neolithic to the Iron Age". I'm not an expert in this field (something I regret), and newer finds and research might invalidate this long-held claim, but I nevertheless have interest in...