Simple stone tools are the earliest human artifacts that archaeologists study.
Small cobbles were first broken to produce sharp edges in Africa between 3 and 2 million years ago.
Prior to the introduction of cast metals about 5000 years ago, most tools with cutting edges were made of stone.
Stone tools were sometimes works of art and important symbols of status.
Sharp fragments of stone are perhaps the most common prehistoric artifacts on earth.
The earliest worked pieces of stone have been found in East Africa dating to 2.6 million years ago.
Our ancient ancestors may also have used pieces of wood or bone for tools, but these have not survived.
Stone can be shaped in a variety of ways.
The technique for making stone tools by intentionally removing a series of flakes is called flaking or knapping.
Archaeologists often refer to shaped stone artifacts as lithics, or lithic artifacts.
Fracture Mechanics and Raw Material
Fracture mechanics is the concept used to describe how materials break.
The key to making stone tools is to use a raw material that will break in a predictable way and produce a sharp edge.
The makers of stone tools sought hard, fine-grained, crystalline rocks.
The most common materials used were a form of cryptocrystalline quartz including basalt, obsidian jasper, quartzite, chert, and flint.
A piece of raw material for making stone tools is usually called a nodule or core.
Flint, or chert, was the type most often used prehistorically.
The term chert is commonly used in North America.
The term flint is more commonly used for this material throughout the Old World.
Predictable fracture is the important characteristic of this material so that desired shapes can be achieved by flaking.
Because of the cone of fracture and the nature of the material itself, flakes have a number of distinctive characteristics.
The place where force was applied to remove the flake is called the striking platform.
The outer surface of the flake is called the dorsal surface.
The inner, fresh surface of the flake itself is called the bulbar, or ventral, surface.
Making Stone Tools
A flake can be removed from core by either a blow or pressure.
The technique of striking stone to remove a flake is called percussion.
Pressure flaking is the term used to describe removals made by pressing a point into the edge of a core.
Percussion can be done using a hard hammer, hammer and anvil, or soft hammer.
The term hard hammer refers to the use of a hammer of equal or greater hardness than the core.
The hammer and anvil method is performed when the core is held in the hand and struck against a rock fixed in the ground.
Soft hammer means the use of a hammer of lighter, softer material, usually antler, bone, or even wood.
Percussion can be direct or indirect.
Pressure flaking involves the use of a pointed tool to press on the edge of a core to remove very long, narrow flakes.
Usually of antler or bone was used.
Copper was sometimes used for this pointed tool as well.
A distinction is made between flakes and blades.
Blades are simply long, narrow flakes.
Blades can be removed by direct or indirect percussion.
Blades were invented rather late in the Paleolithic period.
Two kinds of blades can be identified, hard hammer and soft hammer blades.
Tools are often separated as core tools or flake tools.
Another distinction is made between unifacial tools or bifacial tools.
Bifacial tools are often pointed implements like projectile points.
Tools are often intentionally shaped to a specific form by secondary flaking.
The technique for further shaping flakes, blades, and other pieces into specific forms is called retouching.
Blades are commonly retouched into a variety of shapes.
Making Sense of Stone Tools
There are many ways to study the results of prehistoric stone tool production.
Experimental studies are common.
Typology is the conventional approach to classifying stone tools.
Studies of the process of making stone tools often involve a concept or method known as the chaîne opératoire.
Microwear analysis is one of the more effective techniques used for studying how lithic artifacts were used.
After the stone artifacts have been cleaned and numbered, the process of sorting, classifying, measuring and analysis begins.
The initial sorting is often based on the basic technological types of core and flake and tools.
It is often necessary to draw stone tools in order to illustrate the characteristics of the artifact and the details of manufacture and use.
Today, the combination of laser and photo technology is used.
Typology
A hand axe is a large core tool with a distinctive shape that is pointed at one end and rounded at the other.
Functionally, the hand axe was an all-purpose implement.
Stylistically, there are distinctive types of hand axes that show regional differences in East Africa.
Hand axe production changed over time as soft hammer flaking was incorporated into the process.
The set of stone tools from a site is known as a lithic assemblage.
Assemblages of lithic artifacts from a particular time period are characteristic of archaeological cultures.
Artifact types have changed over time.
The Acheulean assemblages of the Lower Paleolithic are characterized by hand axes and their close relatives.
The Middle Paleolithic assemblage is distinguished by a multitude of flake tools, scrapers, burins, points, along with a few hand axes and other bifacial tools.
Blade technology characterizes the Upper Paleolithic, after 40,000 years ago.
There are striking differences between the artifact types in the New World and the Old World.
Most artifacts in the early prehistory of the New World were bifaces.
They were largely in the form of projectile points for spears and later for the bow and arrow.
Most of the unifacial artifacts from the Archaic and Woodland periods are irregular in appearance.
Flakes predominate in New World industries.
Chaîne Opératoire
The French term, chaîne opératoire, refers to the steps in the process of production.
The chaîne opératoire is defined by the different stages of production from the acquisition of raw material to the final abandonment of the objects.
Such studies focus on the waste material, on refitting, on human motor abilities and skills, knowledge, and experience as well as the end products of the process (tools).
The life history of a lithic artifact involves four major stages: the procurement of raw material, the technology used to make the tool, function, and discard.
Technology can be divided into primary reduction, secondary reduction, and typology.
Studying the operational steps provides more awareness of the relationship among the components in the sequence.
Choices that are made in one stage affect decisions in another.
There is a distinction between expedient and curated tools.
Archaeological Thinking: Stone Tools and Hunter-Gatherers in Western Nevada
The stone tools of hunter-gatherers in the Carson Sink region of western Nevada were investigated.
Archaeological sites occur both at low elevations on the valley floor and at higher elevations in the surrounding mountains.
Bifacial artifacts were made and used primarily in the mountains and simple flake tools were more common on the valley floor.
At the mountain sites there was a clear difference between sites where bifaces were made or repaired and used as tools and sites where bifaces were used as cores.
Refitting
Reassembled objects provide a great deal of information about the site and past human activities.
Refitting is done with a variety of archaeological materials but most commonly with lithics, pottery, and bone.
An example of refitting comes from the late Paleolithic site of Sitra in northwestern Egypt.
Archaeological Thinking: How Many Layers?
The Lower Paleolithic site of Terra Amata is located on the Mediterranean Coast of France.
Stone artifacts and animal bones were found in a series of layers of fossil dunes and beach sand.
At the time of the excavation of the site, these different layers were thought to represent many different episodes of human activity at this 250,000 year-old beach site.
Based on the refitting study, it appears that there were only 2-3 possible periods of activity at the site rather than many as originally thought
Microwear Analysis
Microwear analysis and involves the use of microscopes to study the edges of stone tools.
This kind of analysis began in the second half of the 20th century.
Experimental studies allowed researchers to characterize polishes specific to certain kinds of materials and activities.
Stone tools were often used to make other tools of bone, antler, wood, and other materials.
Science in Archaeology: Stone Tools and Food
A high-powered microscope was used to examine the edges of stone artifacts from the 1.5 million year old site of Koobi Fora in East Africa.
Experimental work demonstrated that different materials left different kinds of traces in the form of polish on the edges of tools.
About 10% of the flakes had indications of meat cutting, slicing of soft plant material, and the scraping and sawing of wood.
Example: The Careful Flintknapper
The site called Meer is located in northern Belgium.
The site dates to approximately 8000 B.C. and belongs to the very latest Paleolithic in this area.
Five distinct clusters of artifacts were recognized on the occupation floor at the site.
Sites such as Meer challenge archaeologists to learn something beyond their approximate age based on the kinds of tools that were found.
One of the first questions to be answered at Meer was whether the artifacts came from a single episode of residence.
Refitting documented the vertical and the horizontal integrity of the site and argued strongly for a single occupation at Meer.
The archaeologists believe that different concentrations represent different types of activities.
Concentration I at Meer was a living area with more varied daily activities represented.
Concentration IV was focused on making bone and antler tools.
Other Stone Artifacts
There were many uses of stone in prehistory and only some involved shaping stone by flaking to make a useful tool.
A variety of techniques were employed to shape stone for various purposes.
Blocks of stone were shaped into pieces for construction, into statues, figurines, bowls and other containers, grinding slabs, beads, and many other forms by hammering, pecking, grinding, and polishing.
Often a combination of techniques was used to make the final product.
