Bronze was revolutionary in other ways. Sure, copper occurs in native metallic form, but even once you find out that mixing it with certain minerals yields a mu

Bronze was revolutionary in other ways. Sure, copper occurs in native metallic form, but even once you find out that mixing it with certain minerals yields a much better metal, you have other problems. Namely that the mineral that gives the best alloy, cassiterite, or SiO2, only occurs in large quantities thousands of kilometers away from your copper deposits. Trade between regions that had hitherto had little contact became a thing. Iron, as known to the ancients, was in many ways inferior to bronze. Iron with low carbon content is malleable but soft, whereas iron with too much carbon is hard but brittle. It took a long time for people to painstakingly learn to make iron that was consistently as good as bronze, and even longer to learn how to further refine iron into consistent-quality steel, a process that also required huge amounts of energy compared to bronzemaking.