We know that prehistoric people used tools made from copper, gold, and iron, but we also know that they were not capable of mining and/or smelting for many years into the future.
So, how did they obtain that metal they used to make tools?
Initially, scientists believe our ancestors found these metals in nature. They could have been found as nuggets while panning in a river or digging, for example.
The earliest known copper artifacts are around 8,000 years old, and items made from gold appeared a few millennia later.
The Ancient Egyptians managed to produce objects made from meteoritic iron, which they likely happened on by accident.
Around 5,000 years ago, humans moved from the Stone Age into the Copper Age, thanks to a capability for smelting. It involved heating copper ores in stone or ceramic crucibles that separated metal from its impurities.
We don’t know how this was first achieved, but like most discoveries, it was probably just one curious cookie who wondered what would happen if they blew hot air through hollow sticks to increase the temperature of a furnace.
It was likely a happy accident that the carbon in the wood reacted with the oxygen in the ore, converting it to carbon dioxide and freeing the copper.
This enabled the creation of new tools and weapons that oustripped their stone predecesors. It hardened when it was hammered and was able to be melted down into molds as well.
Things really took off around 3,000 BCE, though, when they began to mix copper with tin and creating bronze.
The Bronze Age saw the creation of many more alloys as people experimented – a process that really has never abated.
It came to an end with the advent of the Iron Age, when humans figured out how to smelt iron from rocks.
At first, they struggled to reach high enough temperatures to melt the metal. They had to make due with wrought iron for a while, but around 300 BCE, Chinese metalworkers invented a bellows that pumped up the heat.
Iron might not have been as strong as bronze, but it was a lot cheaper, as it was more abundant than tin. Later, we would use it to create steel, which was essential to a lot of the materials that ushered in the modern age.
It’s really amazing, actually, to think of how far we’ve come.
And how much of it could have gone a different way entirely.
If you thought that was interesting, you might like to read about why we should be worried about the leak in the bottom of the ocean.