archaeology Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, ...

, ground stone is a category of

stone tool Stone tools have been used throughout human history but are most closely associated with prehistoric cultures and in particular those of the Stone Age. Stone tools may be made of either ground stone or knapped stone, the latter fashioned by a ...

formed by the grinding of a coarse-grained

tool stone In archaeology, a tool stone is a type of stone that is used to manufacture stone tools, or tools that use stone as raw material. Generally speaking, tools that require a sharp edge are made using cryptocrystalline materials that fracture i ...

, either purposely or incidentally. Ground stone tools are usually made of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture (geology), texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained matri ...

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

, or other

cryptocrystalline Cryptocrystalline is a rock microstructure, rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light. Among the sedimentary rocks, chert a ...

and

igneous Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial ...

stones whose coarse structure makes them ideal for grinding other materials, including plants and other stones. Organic and inorganic materials are processed on ground stones into edible products. They are sometimes the only artefacts preserved on archaeological sites and are found worldwide.

Origin

The adoption of ground

stone technology Stone tools have been used throughout human history but are most closely associated with prehistoric cultures and in particular those of the Stone Age. Stone tools may be made of either ground stone or knapped stone, the latter fashioned by a c ...

is associated closely with the

Neolithic The Neolithic or New Stone Age (from Ancient Greek, Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revo ...

, also called the New Stone Age. The

Stone Age The Stone Age was a broad prehistory, prehistoric period during which Rock (geology), stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended b ...

comes from the three-age system developed by

Christian Jürgensen Thomsen Christian Jürgensen Thomsen (29 December 1788 – 21 May 1865) was a Danish antiquarian who developed early archaeological techniques and methods. In 1816 he was appointed head of 'antiquarian' collections which later developed into the Na ...

. In the Levant ground stones appear in

Mesolithic The Mesolithic (Ancient Greek language, Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic i ...

2 (

Natufian The Natufian culture ( ) is an archaeological culture of the late Epipalaeolithic Near East in West Asia from 15–11,500 Before Present. The culture was unusual in that it supported a sedentism, sedentary or semi-sedentary population even befor ...

). In prehistoric

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, ground stone tools appear during the

Japanese Paleolithic The is the period of human inhabitation in Japan predating the development of pottery, generally before 10,000 BC. The starting dates commonly given to this period are from around 40,000 BC, with recent authors suggesting that there is good evi ...

, possibly predating adoption elsewhere in the Neolithic by 25,000 years.

Creation

Ground stones were created and used for a wide variety of reasons. Each use resulted in a different development and process by which a person created their ground stone. For example, the process for creating the head of a hammer is different from the process used to create a detailed decoration piece for one’s home. That being said, some processes are basic to most ground stone making. When choosing what type of stone to use for a ground stone tool, toughness is the most important factor. If the stone is not tough enough to withstand hard hits and instead just flakes and cracks easily, the work done to create the tool has gone to waste. A stone that will not shear, flake, or crack when tested against large impacts is the most important aspect when choosing what kind of stone to use. Examples of this kind of stone include

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and other

and

rocks.

Cryptocrystalline Cryptocrystalline is a rock microstructure, rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light. Among the sedimentary rocks, chert a ...

rocks are good to use for ground stones because they have a very fine grain structure. This is helpful because the smaller the grains are in a rock, the harder the rock is. Holes could be ground out of stones with the use of sharp pointed stones or hardened sticks. By spinning the ground stone with one's hands and applying substantial pressure to the sharp point into the ground stone, a hole could be drilled into the stone with a large amount of time and effort. Sand would be used to help quicken the process by putting it in the partially formed hole as the sharp point was being pressed. The sand would help grind more of the stone away. To put a hole all the way through a piece of stone, it would be first drilled half way in one direction and be finished on the opposite side. Some ground stone tools are incidental, caused by use with other tools: manos, for example, are hand stones used in conjunction with

metate A metate (or mealing stone) is a type or variety of quern, a ground stone tool used for processing grain and seeds. In traditional Mesoamerican cultures, metates are typically used by women who would grind nixtamalized maize and other organi ...

s and other grinding slabs (querns), and develop their ground surfaces through wear. Other ground stone tools include

adze An adze () or adz is an ancient and versatile cutting tool similar to an axe but with the cutting edge perpendicular to the handle rather than parallel. Adzes have been used since the Stone Age. They are used for smoothing or carving wood in ha ...

celts The Celts ( , see Names of the Celts#Pronunciation, pronunciation for different usages) or Celtic peoples ( ) were a collection of Indo-European languages, Indo-European peoples. "The Celts, an ancient Indo-European people, reached the apoge ...

, and

axe An axe (; sometimes spelled ax in American English; American and British English spelling differences#Miscellaneous spelling differences, see spelling differences) is an implement that has been used for thousands of years to shape, split, a ...

s, which are manufactured using a labor-intensive, time-consuming method of repeated grinding against a harder stone or with sand, often using water as a

lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, ...

. These tools are often made using durable finer-grained materials rather than coarse materials. In the North American arctic, tools made of ground slate were used by the Norton,

Dorset Dorset ( ; Archaism, archaically: Dorsetshire , ) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by Somerset to the north-west, Wiltshire to the north and the north-east, Hampshire to the east, t ...

, and

Thule Thule ( ; also spelled as ''Thylē'') is the most northerly location mentioned in ancient Greek and Roman literature and cartography. First written of by the Greek explorer Pytheas of Massalia (modern-day Marseille, France) in about 320 BC, i ...

tool cultures, among others. Common forms of these tools were projectile points and ulus. These tools were often purpose-made by creating a blank, either by chipping or using a technique where the slate was sawed partway through on one or both sides and then snapped into a blank, then finished by grinding with abraders or whetstones.

Uses

When making the head of an axe out of stone, the piece would be made so it could be hafted. In order to have the stone hafted onto a larger piece, like wood or bone, the ground stone may have at least two notches ground out of one side of the stone, making grooves for the hafting material to lie inside. These grooves would ensure that the stone would not move when struck with a large force. Tough hide would then be wound around the handle and inside the grooves, binding the ground stone and the handle together. Ground stones were often used as dinnerware. Using large stones,

lithic reduction In archaeology, in particular of the Stone Age, lithic reduction is the process of fashioning stones or rocks from their natural state into tools or weapons by removing some parts. It has been intensely studied and many archaeological industrie ...

would be done for long periods of time to create bowls and pots for food. Jewelry, beads, ear spools and other decorative ground stones were a sign of high status due to the time and effort needed to make pieces of such small size and detail. When mashing up seeds and leaves into powders, rounded and smooth ground stones would be used inside a stone bowl. This pair of tools is called a

mortar and pestle A mortar and pestle is a set of two simple tools used to prepare ingredients or substances by compression (physics), crushing and shear force, grinding them into a fine Paste (rheology), paste or powder in the kitchen, laboratory, and pharmacy. ...

. The material would be placed into the mortar and the pestle would be moved and pressed into the mortar to grind the material into a fine powder. This process could be used for medicine and cooking. The mortar and pestle are still used today for many cooking recipes.

Ground stones life

Once shaped into an active (making the action, e.g. handstones) or passive (receiving the action, e.g. slab) tool, the stone is used to process a large range of products. At the end of its life, the stone can be recycled - either reused as a ground stone, used as a construction stone, or discarded

Analytical methods

In archaeology, ground stones are studied to document past activities, agriculture strategies and the process of domestication. Ground stones technology was identified as daily life technology associated with cereals processing. However, their study has shown that they are more complex to understand and have multi-function. Ethnographic studies are essential to define the research question but are not enough to correctly determine the function of ground stones. Typology, ethnographic studies and experimental replicas help understand groundstone technologies. Typical methods are used to analyse them: the trace of wear and the analysis of botanical residues (starch grains and phytoliths).

Use-wear analysis

This technique analyses the trace of wear left by the types of actions (pounding, grinding, cutting). The trace of wear is specific to the action but also the type of product (organic or inorganic) process. Handstones for cereals and hide processing were distinguished using this method.

Botanical remains

Starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diet ...

grains and phytoliths are botanical remains which are well preserved in archaeological context and are small enough to be trapped in the micro-crevice of a ground stone.Torrence, R. and Barton, H. (2016). Ancient Starch Research. Routledge. Analyzing the botanical remains is essential to precise the function of the stones. A standardized protocol is used to study plant remains. First, there are extracts from the ground stones, using a toothbrush and an ultrasonic bath. Then, the residues are observed under a polarised microscope. And finish, starch are compared to a reference collection of experimental modern starch grains.

References

*Adams, J. L. (1988). Use-Wear Analyses on Manos and Hide-Processing Stones. Journal of Field Archaeology, 15 (3), pp. 307–315 *Adams, J. L. (2014). Ground stone use-wear analysis: a review of terminology and experimental methods. Journal of archaeological science, 48, pp. 129–138. ccessed 10 March 2022*Banning, Edward Bruce. ''The archaeologist's laboratory: the analysis of archaeological data.'' Kluwer Academic/Plenum Publishers, New York. 2000, p. 151. *Bender, Tricia R. "Ground Stone Artifacts: Series in Ancient Technologies: The Office of the State Archaeologist at The University of Iowa since 1959." Ground Stone Artifacts: Series in Ancient Technologies: The Office of the State Archaeologist at The University of Iowa since 1959. N.p., n.d. Web. 17 Nov. 2013. . *Fagan, Brian. ''Ancient North America.'' Thames & Hudson, London. 2005, p. 191-99. *Moore, D.T., 1983, Petrological aspects of some sharpening stones, touchstones, and milling stones. In ''The Petrology of Archaeological Artefaces.'' Clarendon Press, Oxford. *"Native Americans:Historic:The Illinois:Technology:Tools:Ground Stone." Native Americans:Historic:The Illinois:Technology:Tools:Ground Stone. N.p., n.d. Web. 18 Nov. 2013. . *Sepp, Siim. "Conchoidal Fracture." Sandatlas. N.p., n.d. Web. 18 Nov. 2013. . *Torrence, R. and Barton, H. (2016). Ancient Starch Research. * Wright, Katherine. "Craft Production and the Organization of Ground Stone Technologies." London's Global University. N.p., n.d. Web. 18 Nov. 2013. {{Prehistoric technology Lithics Neolithic