Arrow-heads, axe-heads, lance-heads, and knives, made of granite, jade, serpentine, jasper, basalt, and other hard stones. The first were discovered on the banks of the Somme, near Amiens and Abbeville, but others have been discovered in Belgium, Germany, Italy, etc. They were the rude instruments of men before the use of metal was known.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Flint Implements from Fact Monster: