Stone tool
From Wikipedia, the free encyclopedia
A stone tool is, in the most general sense, any tool made of stone. Although stone-tool-dependent cultures exist even today, most stone tools are associated with prehistoric societies that no longer exist.
The study of stone tools is often called lithic analysis by archaeologists. Stone tools may be made of chipped stone or ground stone. A person who makes chipped stone implements is called a flintknapper. In addition to tools, many minerals were used to make arrow heads and spear points.
Chipped stone tools are made from cryptocrystalline materials such as chert, radiolarite, chalcedony or obsidian via a process known as lithic reduction. One simple form of reduction is to strike stone flakes from a nucleus (core) of material using a hammerstone or similar hard hammer fabricator. If the goal of the reduction strategy is to produce flakes, the remnant lithic core may be discarded once it has become too small to use. In some strategies, however, a flintknapper reduces the core to a rough unifacial or bifacial preform, which is further reduced using soft hammer flaking techniques or by pressure flaking the edges. More complex forms of reduction include the production of highly standardized blades, which can then be fashioned into a variety of tools such as scrapers, knives, sickles and microliths. In general terms, chipped stone tools are nearly ubiquitous in all pre-metal-using societies because they are easily manufactured, the tool stone is usually plentiful, and they are easy to transport and sharpen.
Prehistoric stone-working techniques of the Palaeolithic are divided into four 'Modes' [1],
The Mode 1 industries (Oldowan, Clactonian) created rough flake tools by hitting a suitable stone with a hammerstone. The resulting flake would have a natural sharp edge for cutting and could afterwards be sharpened further by striking another smaller flake from the edge if necessary (known as retouch). These early toolmakers may also have worked the stone they took the flake from (known as a core) to create chopper cores although there is some debate over whether these items were tools or just discarded cores [citation needed].
The Mode 2 (eg Acheulean) toolmakers also used the Mode 1 flake tool method but supplemented it by also using wood or bone implements to pressure flake fragments away from stone cores to create the first true hand-axes. The use of a soft hammer made from wood or bone also resulted in more control over the shape of the finished tool. Unlike the earlier Mode 1 industries, the core was prized over the flakes that came from it. Another advance was that the Mode 2 tools were worked symmetrically and on both sides indicating greater care in the production of the final tool.
Mode 3 technology emerged towards the end of Acheulean dominance and involved the Levallois technique. It is commonly associated with Neanderthal Mousterian industry. The long blades of the Upper Palaeolithic Mode 4 industries appeared during the Upper Palaeolithic.
Ground stone tools are manufactured from larger-grained materials such as basalt and some forms of rhyolite, which are not suitable for flaking. Because of their coarse surfaces, many ground stone tools are ideal for grinding plant foods. Some ground stone tools are incidental, caused by use with other tools: manos, for example, are hand stones used in conjunction with metates, and develop their ground surfaces through wear. Other ground stone tools include adzes, celts, and axes, which are manufactured using a labor-intensive, time-consuming method of repeated grinding against a harder stone, often using water as a lubricant. In Europe the adoption of ground stone tools is associated closely with the Neolithic.
[edit] Footnote
- ^ Barton, RNE, Stone Age Britain English Heritage/BT Batsford:London 1997 qtd in Butler, 2005. See also Wymer, JJ, The Lower Palaeolithic Occupation of Britain, Wessex Archaeology and English Heritage, 1999.
