A gold rush makes sense. But a copper rush? Not so much. And yet, perhaps there is more to gold than aesthetics.
Without lignin, there would be no woody plants, no wood, no coal, no charcoal, no fire, no pottery, and certainly no iron or metallurgy.
If the conductivity of copper were ten times less, wires would have to be ten times the cross-sectional area to provide the same conductivity.
The combustion of wood or coal may seem so familiar as to be unworthy of any comment.
The importance of metals, particularly iron, and the importance of the discovery of metallurgy can hardly be exaggerated.