Neanderthal women also liked to style themselves with makeup. They used chunks of manganese dioxide as pigments. And they also used this mineral to make fire, as researchers from Leiden University and TU Delft found.
It may not solely have been vanity that made Neanderthals collect manganese dioxide. During excavations at several Neanderthal sites in France large numbers of small black blocks of manganese have been found. The usual interpretation is that these chunks were used for their colouring properties in body decoration, especially by women and particularly during glacial cycles when, it is argued, pair-bond stability would have been critical. But a team of Leiden and Delft researchers believes the stone age people collected the minerals to make fire as well.
The scientists ground up bits of the mineral to produce a powder. When sprinkled on a pile of wood, the powder lowered the temperature needed to initiate combustion to 250°C, making it much easier to start a fire, they reported last week in Scientific Reports. (Untreated wood failed to ignite at temperatures up to 350°C.
The fact that manganese dioxide reduces wood's auto-ignition temperature combined with archaeological evidence for both fire places and the grinding of manganese dioxide blocks to powder supports the hypothesis that Neanderthals used manganese dioxide to make fire. Or at least they did 50,000 years ago in a place called Pech-de-l'Azé in South Western France.
The project was a collaboration between researchers at the Faculty of Archaeology, Leiden University, and the Faculty 3mE, Department Process and Energy, and brought together expertise in palaeolithic archaeology, combustion research and materials science analytical techniques.
Interestingly, whilst Neanderthals may have sourced and used manganese dioxide in fire making 50,000 years ago, manganese dioxide has important uses today in energy storage (batteries) and potentially in future clean energy production systems.
The selection and use of manganese dioxide for fire making is unknown from the ethnographic record of recent hunter-gatherers. It therefore provides potential significant insights into Neanderthal cognitive capabilities. The actions involved in the preferential selection of a specific, non-combustible material and its use to make fire are not obvious nor intuitive.
The knowledge and insights suggested by Neanderthal selection of manganese dioxide and use in fire-making are surprising and qualitatively different from the expertise commonly associated with Neanderthals.
Peter J. H. et al., Selection and Use of Manganese Dioxide by Neanderthals Scientific Reports | 6:22159 | DOI: 10.1038/srep22159