Olduvai stone chopping tool

From Olduvai Gorge, Tanzania, 1.8-2 million years old

Made nearly two million years ago, stone tools such as this are the first known technological invention. This one is the oldest object in the British Museum.

It comes from an early human campsite in the bottom layer of deposits in Olduvai Gorge, Tanzania. Potassium-argon dating indicates that this bed is between 1.6 and 2.2 million years old from top to bottom. This and other tools are scientifically dated to about 1.8 million years.

Using another hard stone as a hammer, the maker has knocked flakes off both sides of a basalt (volcanic lava) pebble so that they intersect to form a sharp edge. This could be used to chop branches from trees, cut meat from large animals or smash bones for marrow fat - an essential part of the early human diet. The flakes could also have been used as small knives for light duty tasks.

To some people this artefact might appear crude; how can we even be certain that it is humanly made and not just bashed in rock falls or by trampling animals?

A close look reveals that the edge is formed by a deliberate sequence of skilfully placed blows of more or less uniform force. Many objects of the same type, made in the same way, occur in groups called assemblages which are occasionally associated with early human remains. By contrast, natural forces strike randomly and with variable force; no pattern, purpose or uniformity can be seen in the modifications they cause.

Chopping tools and flakes from the earliest African sites were referred to as Oldowan by the archaeologist Louis Leakey. He found this example on his first expedition to Olduvai in 1931, when he was sponsored by the British Museum.