An archaeologist from the University of Leiden, Andrew Sorensen, has described the first material evidence that Neandertals did know how to make a fire in a study published in Scientific Reports , which belies the idea that they only depended on naturally occurring fire, such as natural fires caused by lightning, for example.
To make fire, the Neanderthals struck a piece of pyrite, a mineral containing iron, with flint tools.
Together with the French archaeologist Emilie Claud and the Leiden archeology professor Marie Soressi, Sorensen discovered a very specific microscopic wear in the flint hand axes (also called bifaces) of the Middle Paleolithic, the Neanderthal era. As it explains:
These are the traces you get if you try to generate sparks by hitting a piece of flint against a piece of pyrite. These hand axes are much older than the fire-making tools in which this wear has been found so far.
Sorensen and Claud studied dozens of 50,000-year-old hand axes from various sites throughout France. They found the same distinctive wear in all of them. In addition, with a combination of microscopic research and experiments, Sorensen discovered that traces of wear were specific to fire making.