CATEGORY: ceramics DEFINITION: The addition of small pieces of rock or sand to the paste used in creating a ceramic object.
CATEGORY: ceramics DEFINITION: The addition of small pieces of crushed ceramic to the paste used in creating a ceramic object.
CATEGORY: ceramics DEFINITION: The addition of small pieces of crushed shell to the paste used in creating a ceramic object.
CATEGORY: geology; ceramics DEFINITION: One of the processes in the manufacture of steel and other metal artifacts, the heat treatment of hardened steels to improve toughness and reduce brittleness. The steel is reheated to a temperature of around 450? C and then rapidly cooled by quenching. Also, the material added to the paste of a ceramic to make it stronger and give it properties it does not naturally have.
CATEGORY: artifact DEFINITION: An important building material of individual blocks of clay or mud, some with tempering of sand or straw. Bricks, which are not always rectangular, may be baked in a kiln to terra cotta or sun-dried -- which is referred to as mud-brick or adobe. The chief building material throughout the Near East has always been mud-brick. Bricks can be used as dating criteria, especially when they bear stamped inscriptions. Decorative glazed bricks first appeared in Assyrian times, as at Ishtar Gate in Babylon.
CATEGORY: artifact DEFINITION: Pottery whose fabric embodies crushed calcite (either shell or mineral grit) as a tempering agent, used especially for kitchen wares such as storage jars, cooking pots, and bowls.
CATEGORY: technique DEFINITION: Any of various techniques used to study artifacts made from fired clay to obtain archaeological data. Color is objectively described by reference to the Munsell soil color charts. Examination under the microscope may reveal the technique of manufacture and allow the identification of mineral grains in the tempering, which will identify the area of manufacture. Refiring experiments often show how the original baking was done.
CATEGORY: ceramics DEFINITION: A type of medieval pottery of western Brittany, made from the 10th-18th centuries. It is typically very soft and uses talc as the temperingmaterial. This unusual pottery was a distinctive product of the Breton culture.
SYNONYMS OR RELATED TERMS: fiber tempering CATEGORY: ceramics DEFINITION: Any claypottery to which grass or root fibers have been added as a temperingmaterial. This ware is the earliest pottery in Caribbean South America and is the oldest pottery in the United States, making its appearance in Archaic shell mounds in Georgia and Florida before 2500 BC.
CATEGORY: ceramics DEFINITION: The process of heating raw ceramics to a high temperature, driving all the water out of the paste and (depending on the composition of the paste and tempering) causing new chemical bonds to form within the paste.
SYNONYMS OR RELATED TERMS: grass-tempered pottery CATEGORY: ceramics DEFINITION: Pottery either marked or tempered with grass. In western Britain, there are examples of pottery covered with 'grass' impressions from Ulster, the Hebrides, and Cornwall, especially around the 5th-6th centuries AD. The term also refers to crude handmade ware made in various parts of Frisia in the Migration Period and in certain parts of southern England in the Early Saxonperiod in which ferns and other organic material was used as tempering.
CATEGORY: artifact DEFINITION: Pottery embodying chopped grass or straw in its fabric as a tempering agent. Grass-tempered wares are well represented amongst pagan Saxon communities of the immediate post-Roman period in southern and eastern England; indeed the presence of such pottery is the basis upon which sites of the period are recognized.
CATEGORY: technique DEFINITION: The study of metals. Metal artifacts and the tools or waste products of their manufacture are examined to reconstruct manufacturing processes, the source of raw materials, and the usage. This may be done by the various techniques of chemical analysis, or may involve metallographic examination under a microscope. In the case of copper, bronze, and other non-ferrous metals, such analysis may yield information about alloys, casting, cold-working, and annealing. For iron and steel, there may be information about forging, carburization, quenching, and tempering.
SYNONYMS OR RELATED TERMS: Plains Village Indian CATEGORY: culture DEFINITION: One of three broad cultural traditions (along with Central Plains and Coalescent) which constitute the Plains Village Indian or Plains Village Pattern of c 1000-1500 AD. There were many permanent farming village sites along the central Missouri River trench in North and South Dakota. The culture is characterized by a specially developed strain of cold-resistant, quick-maturing maize, by the bison scapula hoe, and by permanent dwellings in the form of the semisubterranean timber-and-earth lodge. Often palisaded and constructed on high promontories overlooking a river, villages of over 100 dwellings are quite common. Ceramics, though Woodland derived, bear evidence of some Mississippian influence, such as shell tempering. The tradition disappeared, due to drought and/or alien incursions, by 1500. Historic tribes such as the Mandan, Arikara, and Hidatsa are thought to be the cultural heirs to the tradition.
CATEGORY: technique DEFINITION: A photograph of an object or part of an object taken at high magnification in order to reveal details of form and structure. Many of these are taken automatically for documentation purposes during the use of such instruments as the scanning electron microscope, the petrological microscope, binocular microscope, and the optical microscope. Photomicrographs can reveal the detailed structure of palaeobotanical remains, the presence of different tempering materials in pottery, analysis of thin sections, the use-wear on artifacts, or the details of structure in metals which can help to identify metalworking procedures.
CATEGORY: geology DEFINITION: An alloy of iron and carbon in which the carbon content amounts to about 2 percent or less. Steel appears in the archaeological record during the Iron Age and was usually produced by carburization of wrought iron. In this process, the iron is heated in a hearth with charcoal to about 800 degrees Centigrade. Carbon diffuses into the surface of the metal to make steel. As only the surface is affected, only thin strips of steel could be made by this method. Some Iron Age artifacts are made of such steel strips forged together. Further processes such as quenching and tempering were known from Roman times. Viking swords combined the strength of wrought iron with the hardness of steel, using a technique known as pattern welding.
SYNONYMS OR RELATED TERMS: calcite-gritted ware CATEGORY: artifact DEFINITION: Pottery whose fabric embodies crushed calcite (either shell or mineral grit) as a tempering agent, used especially for kitchen wares such as storage jars, cooking pots, and bowls.