phlogiston - 2-3-2016 at 01:23
Archeologists found that adding a little manganese dioxide to wood lowers its ignition temperature and suggest that the blocks of mineral MnO2 found
near neanderthal campfires in a cave in France were used for that purpose:
http://www.nature.com/articles/srep22159
Pretty interesting. Previously they were thought to be used as a brown pigment.
I have some doubt that people experienced with starting a fire would need this method, but if true it seems surprisingly advanced.
Mabus - 3-3-2016 at 09:50
For a moment I thought this was about morons starting forest fires with MnO2. 
Glad it wasn't the case.
Anyway, this is a very interesting discovery, I wonder how come this method isn't used around places that have easy access to manganese ore.