A flintstone

Chalk cliffs at Dover cliffs. The slanting dark lines in the chalk are flint.

Flint handaxe from Hoxne, England. This is the first published picture of a handaxe in archaeological history. The handaxe was not a weapon; it was a tool used in butchering the carcasses of mammals.

Flint, or flintstone, is a kind of sedimentary rock, made of silica.

Bands of flint are found embedded in chalk and other kinds of soft limestone.

When the chalk is eroded, the hard flint nodules survive as pebbles on a shingle beach. It may happen that the pebbles later get cemented into another rock, such as a puddingstone. In this way, they make up a sedimentary rock for the second time.