Amadou

Amadou was a precious resource to ancient people, allowing them to start a fire by catching sparks from flint struck against iron pyrites.

Bits of fungus preserved in peat have been discovered at the Mesolithic site of Star Carr in the UK, modified presumably for this purpose.

[1] Remarkable evidence for its utility is provided by the discovery of the 5,000-year-old remains of "Ötzi the Iceman", who carried it on a cross-alpine excursion before his death and subsequent ice-entombment.

[8] Before such uses, amadou needs to be prepared by being pounded flat, and boiled or soaked in a solution of nitre.

The result is initially hard and must be pounded with a blunt object to soften and flatten it.