Flint is a very hard sedimentary rock that forms within limestone through the accumulation and transformation of microscopic marine remains rich in silica. It typically displays a distinctive type of breakage known as a conchoidal fracture, which produces extremely sharp edges. This property made it an invaluable natural resource during prehistory for the manufacture of tools and weapons, as well as for fire-lighting. Between the sixteenth and nineteenth centuries, flint was also widely used to produce gunflints for firearms.
In the upper part of Bosc Gran, flint outcrops can be found displaying a range of colours, including grey, black, brown and reddish hues, depending on their mineral composition. At Cap de Salou, various archaeological finds confirm the use of this type of stone since the Neolithic period.
