The Watering Hole: April 14 – The Copper Age

In 1991, in the Italian Alps, the mummified remains of a man named ‘Ötzi’ by his 20th century care takers was discovered. Analysis of the remains showed that Ötzi had died approximately 5300 years before he had been found. One of the items that Ötzi was carrying was a copper axe; not stone, not brass and not iron.

Ötzi's Copper Axe

This piqued my curiosity because, when I was young, I was taught that the progress in man made tools progressed along the line of stone-bronze-iron/steel. Why was Ötzi carrying a copper axe? I dug a little into the history of copper and found that a Copper Age was a step into the age of bronze. Copper was smelted as various times by cultures on many continents. Examples of smelted copper have been found in the Americas, Europe, Africa and Asia. Copper earlier harvested in its elemental form was generally useless as a material for making tools because there were impurities in the mix making some molecules insoluble and non-reactive.

Until smelting was discovered as a process, metals could not be purified from their oxides, nitrates or salts. The elemental copper was found mostly as flakes. A notable exception to this was the Old Copper Complex in central North America where large copper nuggets were found by Neolithic peoples; starting, approximately, 4000 BCE. It seems that copper was the first metal to be smelted. A fortunate accident with another ore (usually tin) resulted in bronze and copper’s position in tool making was short-lived.

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