Sea glass are naturally weathered pieces of the anthropogenic glass fragments of typically drinkwares , which often have the appearance of tumbled stones . Sea glass is physically polished and chemically weathered glass found on beaches along bodies of salt water . These weathering processes produce natural frosted glass . Sea glass is used for decoration, most commonly in jewellery . "Beach glass" comes from fresh water and is often less frosted in appearance than sea glass. Sea glass takes 20–40 years, and sometimes as much as 100–200 years, to acquire its characteristic texture and shape. It is also colloquially referred to as drift glass from the longshore drift process that forms the smooth edges. In practice, the two terms are used interchangeably.
53-416: Sea glass begins as normal shards of broken glass that are then persistently tumbled and ground until the sharp edges are smoothed and rounded. In this process, the glass loses its slick surface but gains a frosted appearance over many years. Naturally produced sea glass ("genuine sea glass") originates as pieces of glass from broken bottles, broken tableware, or even shipwrecks, which are rolled and tumbled in
106-400: A differentiated culture which was earlier thought to be typical Indus Valley civilisation (IVC) culture. Pottery is durable, and fragments, at least, often survive long after artifacts made from less-durable materials have decayed past recognition. Combined with other evidence, the study of pottery artefacts is helpful in the development of theories on the organisation, economic condition and
159-667: A hard and durable form. The place where such wares are made by a potter is also called a pottery (plural potteries ). The definition of pottery , used by the ASTM International , is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products". End applications include tableware , decorative ware , sanitary ware , and in technology and industry such as electrical insulators and laboratory ware. In art history and archaeology , especially of ancient and prehistoric periods, pottery often means only vessels, and sculpted figurines of
212-459: A locality. The main ingredient of the body is clay . Some different types used for pottery include: It is common for clays and other raw materials to be mixed to produce clay bodies suited to specific purposes. Various mineral processing techniques are often utilised before mixing the raw materials, with comminution being effectively universal for non-clay materials. Examples of non-clay materials include: The production of pottery includes
265-416: A more distant connection between groups, such as trade in the same market or even relatively close settlements. Techniques that require more studied replication (i.e., the selection of clay and the fashioning of clay) may indicate a closer connection between peoples, as these methods are usually only transmissible between potters and those otherwise directly involved in production. Such a relationship requires
318-581: A rough guide, modern earthenwares are normally fired at temperatures in the range of about 1,000 °C (1,830 °F) to 1,200 °C (2,190 °F); stonewares at between about 1,100 °C (2,010 °F) to 1,300 °C (2,370 °F); and porcelains at between about 1,200 °C (2,190 °F) to 1,400 °C (2,550 °F). Historically, reaching high temperatures was a long-lasting challenge, and earthenware can be fired effectively as low as 600 °C (1,112 °F), achievable in primitive pit firing . The time spent at any particular temperature
371-405: A tumbler, sand, and glass are necessary. A number of characteristics highlight the differences between artificial sea glass and natural sea glass, starting with the coloration and surface texture of each piece. An example of natural sea glass will usually have a frosty, almost powdery texture at different points. One of the most reliable indicators for natural sea glass is a C-shaped design all over
424-512: A waterproof barrier, and improve its durability. Below are the major types of glazing commonly used in pottery: 1. Glossy Glaze - Produces a shiny, reflective surface. - Highlights intricate patterns and textures. - Often used for decorative purposes. 2. Matte Glaze - Provides a smooth, non-reflective finish. - Suitable for modern and minimalist designs. - Ideal for functional wares like plates and mugs, as it minimizes glare. 3. Transparent Glaze - Can be glossy or matte. - Allows
477-427: Is pottery which is broken into worn pieces and shards and found on beaches along oceans or large lakes . Sea pottery has been tumbled and smoothed by the water and sand, creating small pieces of smooth, frosted pottery. It is often collected with more common sea glass by beachcombers . Sea pottery originates from pottery, including earthenware , stoneware and porcelain which breaks into smaller pieces and
530-401: Is also important, the combination of heat and time is known as heatwork . Kilns can be monitored by pyrometers , thermocouples and pyrometric devices . The atmosphere within a kiln during firing can affect the appearance of the body and glaze. Key to this is the differing colours of the various oxides of iron, such as iron(III) oxide (also known as ferric oxide or Fe 2 O 3 ) which
583-482: Is associated with brown-red colours, whilst iron(II) oxide (also known as ferrous oxide or FeO) is associated with much darker colours, including black. The oxygen concentration in the kiln influences the type, and relative proportions, of these iron oxides in fired the body and glaze: for example, where there is a lack of oxygen during firing the associated carbon monoxide (CO) will readily react with oxygen in Fe 2 O 3 in
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#1732855373210636-498: Is found once in about every 5,000 pieces), and orange (the least common type of sea glass, found once in about 10,000 pieces). These colors are found once for every 1,000 to 10,000 pieces collected. Some shards of black glass are quite old, originating from thick eighteenth-century gin , beer, and wine bottles. Old black glass bottles that had iron slag added during production to increase strength and opaqueness were at times broken in shipment. In order to make artificial sea glass,
689-400: Is important part of archaeology for understanding the archaeological culture of the excavated site by studying the fabric of artifacts, such as their usage, source material composition, decorative pattern, color of patterns, etc. This helps to understand characteristics, sophistication , habits, technology, tools, trade, etc. of the people who made and used the pottery. Carbon dating reveals
742-426: Is lit and the woman runs around the circumference of the mound touching the burning torch to the dried grass. Some mounds are still being constructed as others are already burning. Pottery may be decorated in many different ways. Some decoration can be done before or after the firing, and may be undertaken before or after glazing. Glaze is a glassy coating on pottery, and reasons to use it include decoration, ensuring
795-425: Is made by heating materials, generally including kaolin , in a kiln to temperatures between 1,200 and 1,400 °C (2,200 and 2,600 °F). This is higher than used for the other types, and achieving these temperatures was a long struggle, as well as realizing what materials were needed. The toughness, strength and translucence of porcelain, relative to other types of pottery, arises mainly from vitrification and
848-633: Is normally fired below 1200 °C. Because unglazed earthenware is porous, it has limited utility for the storage of liquids or as tableware. However, earthenware has had a continuous history from the Neolithic period to today. It can be made from a wide variety of clays, some of which fire to a buff, brown or black colour, with iron in the constituent minerals resulting in a reddish-brown. Reddish coloured varieties are called terracotta , especially when unglazed or used for sculpture. The development of ceramic glaze made impermeable pottery possible, improving
901-481: Is not always the case; for example fritware uses no or little clay, so falls outside these groups. Historic pottery of all these types is often grouped as either "fine" wares, relatively expensive and well-made, and following the aesthetic taste of the culture concerned, or alternatively "coarse", "popular", "folk" or "village" wares, mostly undecorated, or simply so, and often less well-made. Cooking in pottery became less popular once metal pots became available, but
954-430: Is placed within the context of linguistic and migratory patterns, it becomes an even more prevalent category of social artifact. As proposed by Olivier P. Gosselain, it is possible to understand ranges of cross-cultural interaction by looking closely at the chaîne opératoire of ceramic production. The methods used to produce pottery in early Sub-Saharan Africa are divisible into three categories: techniques visible to
1007-405: Is shaped by a variety of techniques, which include: Prior to firing, the water in an article needs to be removed. A number of different stages, or conditions of the article, can be identified: Firing produces permanent and irreversible chemical and physical changes in the body. It is only after firing that the article or material is pottery. In lower-fired pottery, the changes include sintering ,
1060-528: Is smoothed by the acidity and motion of an ocean or lake. The sand or grit polishes the edges like a natural tumbler. Much of the sea pottery in the United Kingdom and United States originates from discarded 18th and 19th century porcelain made in Europe and America. Some sea pottery contains discernible patterns, such as flowers, figures, historic places and scenes, or hallmarks, factory stamps and dates which allow
1113-455: Is still used for dishes that benefit from the qualities of pottery cooking, typically slow cooking in an oven, such as biryani , cassoulet , daube , tagine , jollof rice , kedjenou , cazuela and types of baked beans . The earliest forms of pottery were made from clays that were fired at low temperatures, initially in pit-fires or in open bonfires . They were hand formed and undecorated. Earthenware can be fired as low as 600 °C, and
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#17328553732101166-730: Is very uncommon, as is citron , opaque white (from milk bottles), cobalt blue and cornflower blue (from early Milk of Magnesia bottles, poison bottles, artwork, Bromo-Seltzer and Vicks VapoRub containers), and aqua (from Ball Mason jars and certain 19th century glass bottles). These colors are found once for every 200 to 1,000 pieces found. Extremely rare colors include gray , pink (often from Great Depression - era plates ), teal (often from Mateus (wine) bottles), black (older, very dark olive green glass), yellow (often from 1930s Vaseline containers), turquoise (from tableware and art glass), red (often from old Schlitz bottles, car tail lights, dinnerware, or nautical lights, it
1219-400: The "clay matrix" – composed of grains of less than 0.02 mm grains which can be seen using the high-powered microscopes or a scanning electron microscope , and the "clay inclusions" – which are larger grains of clay and could be seen with the naked eye or a low-power binocular microscope. For geologists, fabric analysis means spatial arrangement of minerals in a rock. For Archaeologists,
1272-566: The "fabric analysis" of pottery entails the study of clay matrix and inclusions in the clay body as well as the firing temperature and conditions . Analysis is done to examine the following 3 in detail: The Six fabrics of Kalibangan is a good example of fabric analysis. Body , or clay body, is the material used to form pottery. Thus a potter might prepare, or order from a supplier, such an amount of earthenware body, stoneware body or porcelain body. The compositions of clay bodies varies considerably, and include both prepared and 'as dug';
1325-526: The Russian Far East (14,000 BC), Sub-Saharan Africa (9,400 BC), South America (9,000s–7,000s BC), and the Middle East (7,000s–6,000s BC). Pottery is made by forming a clay body into objects of a desired shape and heating them to high temperatures (600–1600 °C) in a bonfire , pit or kiln , which induces reactions that lead to permanent changes including increasing the strength and rigidity of
1378-503: The ability of the involved parties to communicate effectively, implying pre-existing norms of contact or a shared language between the two. Thus, the patterns of technical diffusion in pot-making that are visible via archaeological findings also reveal patterns in societal interaction. Chronologies based on pottery are often essential for dating non-literate cultures and are often of help in the dating of historic cultures as well. Trace-element analysis , mostly by neutron activation , allows
1431-452: The age. Sites with similar pottery characteristics have the same culture, those sites which have distinct cultural characteristics but with some overlap are indicative of cultural exchange such as trade or living in vicinity or continuity of habitation, etc. Examples are black and red ware , redware , Sothi-Siswal culture and Painted Grey Ware culture . The six fabrics of Kalibangan is a good example of use of fabric analysis in identifying
1484-417: The branches and then grass is piled high to complete the mound. Although the mound contains the pots of many women, who are related through their husbands' extended families, each women is responsible for her own or her immediate family's pots within the mound. When a mound is completed and the ground around has been swept clean of residual combustible material, a senior potter lights the fire. A handful of grass
1537-431: The cultural development of the societies that produced or acquired pottery. The study of pottery may also allow inferences to be drawn about a culture's daily life, religion, social relationships, attitudes towards neighbours, attitudes to their own world and even the way the culture understood the universe. It is valuable to look into pottery as an archaeological record of potential interaction between peoples. When pottery
1590-480: The duration of firing influences the final characteristics of the ceramic. Thus, the maximum temperature within a kiln is often held constant for a period of time to soak the wares to produce the maturity required in the body of the wares. Kilns may be heated by burning combustible materials, such as wood , coal and gas , or by electricity . The use of microwave energy has been investigated. When used as fuels, coal and wood can introduce smoke, soot and ash into
1643-460: The eye (decoration, firing and post-firing techniques), techniques related to the materials (selection or processing of clay, etc.), and techniques of molding or fashioning the clay. These three categories can be used to consider the implications of the reoccurrence of a particular sort of pottery in different areas. Generally, the techniques that are easily visible (the first category of those mentioned above) are thus readily imitated, and may indicate
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1696-430: The following stages: Before being shaped, clay must be prepared. This may include kneading to ensure an even moisture content throughout the body. Air trapped within the clay body needs to be removed, or de-aired, and can be accomplished either by a machine called a vacuum pug or manually by wedging . Wedging can also help produce an even moisture content. Once a clay body has been kneaded and de-aired or wedged, it
1749-481: The foot) is left unglazed or, alternatively, special refractory " spurs " are used as supports. These are removed and discarded after the firing. Some specialised glazing techniques include: Types of Glazing in Pottery. Glazing in pottery is the process of applying a coating or layer of material to ceramics that, when fired, forms a vitreous or glass-like surface. Glazes enhance the aesthetic appeal of pottery, provide
1802-646: The formation of the mineral mullite within the body at these high temperatures. Although porcelain was first made in China , the Chinese traditionally do not recognise it as a distinct category, grouping it with stoneware as "high-fired" ware, opposed to "low-fired" earthenware. This confuses the issue of when it was first made. A degree of translucency and whiteness was achieved by the Tang dynasty (AD 618–906), and considerable quantities were being exported. The modern level of whiteness
1855-443: The former being by far the dominant type for studio and industry. The properties also vary considerably, and include plasticity and mechanical strength before firing; the firing temperature needed to mature them; properties after firing, such as permeability, mechanical strength and colour. There can be regional variations in the properties of raw materials used for pottery, and these can lead to wares that are unique in character to
1908-412: The fusing together of coarser particles in the body at their points of contact with each other. In the case of porcelain, where higher firing-temperatures are used, the physical, chemical and mineralogical properties of the constituents in the body are greatly altered. In all cases, the reason for firing is to permanently harden the wares, and the firing regime must be appropriate to the materials used. As
1961-567: The historical context they provide. Sea pottery is often used in household decorations and furnishings as well as jewellery . Some enthusiasts fill jars with sea pottery to display. Because most sea pottery originates from turn of the 20th century ceramics (glass and ceramics were used more widely for consumables before plastic ) it is becoming increasingly less common to find these pieces. Sea pottery highlights issues related to marine debris and ocean pollution. Many pieces of sea pottery originated from discarded or shipwrecked items, demonstrating
2014-417: The item is impermeable to liquids, and minimizing the adherence of pollutants. Glaze may be applied by spraying, dipping, trailing or brushing on an aqueous suspension of the unfired glaze. The colour of a glaze after it has been fired may be significantly different from before firing. To prevent glazed wares sticking to kiln furniture during firing, either a small part of the object being fired (for example,
2067-431: The kiln which can affect the appearance of unprotected wares. For this reason, wares fired in wood- or coal-fired kilns are often placed in the kiln in saggars , ceramic boxes, to protect them. Modern kilns fuelled by gas or electricity are cleaner and more easily controlled than older wood- or coal-fired kilns and often allow shorter firing times to be used. Niche techniques include: [...] pots are positioned on and amid
2120-487: The late 19th and early 20th centuries, windows , and windshields ). These colors are found about once for every 25 to 100 pieces of sea glass found. Uncommon colors of sea glass include a type of green, which comes primarily from early to mid-1900s bottles of Coca-Cola , Dr Pepper , and RC Cola as well as from bottles of beer. Soft green colors could come from bottles of ink, fruit, and baking soda . These colors are found once in every 50 to 100 pieces. Purple sea glass
2173-576: The late Middle Ages, as European kilns were less efficient, and the right type of clay less common. It remained a speciality of Germany until the Renaissance. Stoneware is very tough and practical, and much of it has always been utilitarian, for the kitchen or storage rather than the table. But "fine" stoneware has been important in China , Japan and the West, and continues to be made. Many utilitarian types have also come to be appreciated as art. Porcelain
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2226-556: The long history of human impact on marine environments. Collectors and environmentalists often work together to clean up beaches, finding sea pottery while also removing harmful debris. Efforts to conserve and protect coastal environments play a crucial role in preserving sea pottery. Beach clean-ups and educational programs help raise awareness about marine pollution and the importance of protecting our oceans. Conservationists emphasize responsible collecting practices to ensure that natural habitats are not disturbed. Certain locations around
2279-424: The object. Much pottery is purely utilitarian, but some can also be regarded as ceramic art . An article can be decorated before or after firing. Pottery is traditionally divided into three types: earthenware , stoneware and porcelain . All three may be glazed and unglazed. All may also be decorated by various techniques. In many examples the group a piece belongs to is immediately visually apparent, but this
2332-1004: The ocean for years until all of their edges are rounded off, and the slickness of the glass has been worn to a frosted appearance. Then, the glass will wash to shore where it may be collected. The color of sea glass is determined by its original source, and most sea glass comes from bottles. Besides pieces of glass, colored sea pottery pieces are often also found. The most common colors of sea glass are kelly green , brown , white , and clear that come predominantly from bottles of beer , juices and soft drinks and fishing floats . The clear or white glass also comes from clear plates and glasses, windshields, windows, and assorted other sources. Less common colours include jade , amber (from bottles for whiskey , medicine , spirits , and early laundry bleach ), golden amber or amberina (mostly from bottles for spirits), lime green (from 1960s bottles for soda ), forest green, and ice- or soft blue (from bottles for soda, medicine, ink , and fruit jars from
2385-454: The outside of the sample. If the design is located on the piece, it is authentic sea glass, since artificial glass will typically not have that particular design. Sea glass usually comes from broken glass bottles or other household items, so pieces found on beaches will not be perfectly shaped, unlike artificial sea glass, often sold as beach glass. Sea pottery Sea pottery (also known as sea china , sea porcelain or beach pottery )
2438-453: The popularity and practicality of pottery vessels. Decoration has evolved and developed through history. Stoneware is pottery that has been fired in a kiln at a relatively high temperature, from about 1,100 °C to 1,200 °C, and is stronger and non-porous to liquids. The Chinese, who developed stoneware very early on, classify this together with porcelain as high-fired wares. In contrast, stoneware could only be produced in Europe from
2491-480: The pottery to be dated using pottery reference guides. Sea pottery shards can give insights into historical trade routes, manufacturing techniques, and daily life in previous centuries. Pottery pieces can be traced back to specific manufacturers and periods, providing information for historians and archaeologists. Collecting sea pottery has become a popular hobby among beachcombers and collectors, with finds being valued not only for their aesthetic appeal but also for
2544-421: The raw materials and cause it to be reduced to FeO. An oxygen deficient condition, called a reducing atmosphere, is generated by preventing the complete combustion of the kiln fuel; this is achieved by deliberately restricting the supply of air or by supplying an excess of fuel. Firing pottery can be done using a variety of methods, with a kiln being the usual firing method. Both the maximum temperature and
2597-727: The same material are called terracottas . Pottery is one of the oldest human inventions , originating before the Neolithic period , with ceramic objects such as the Gravettian culture Venus of Dolní Věstonice figurine discovered in the Czech Republic dating back to 29,000–25,000 BC. However, the earliest known pottery vessels were discovered in Jiangxi , China, which date back to 18,000 BC. Other early Neolithic and pre-Neolithic pottery artifacts have been found, in Jōmon Japan (10,500 BC),
2650-467: The sources of clay to be accurately identified and the thermoluminescence test can be used to provide an estimate of the date of last firing. Examining sherds from prehistory, scientists learned that during high-temperature firing, iron materials in clay record the state of the Earth's magnetic field at that moment. The "clay body" is also called the "paste" or the "fabric" , which consists of 2 things,
2703-569: The underlying decoration or texture of the pottery to show through. - Often used over underglaze decorations. 4. Opaque Glaze - Completely covers the surface of the pottery, hiding any underlying texture or decoration. - Useful for creating uniform, bold colors. 5. Celadon Glaze - A translucent glaze, usually in shades of green or blue. - Originated in China and is popular in East Asian ceramics. - Accentuates carved or textured designs beneath
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#17328553732102756-687: The world are renowned for their abundance of sea pottery. Beaches in the United Kingdom, such as Seaham Beach in County Durham, and sites in the United States, like Glass Beach in California, are famous for their rich deposits of sea pottery and glass. These sites attract tourists and collectors alike, eager to find unique pieces. Pottery Pottery is the process and the products of forming vessels and other objects with clay and other raw materials, which are fired at high temperatures to give them
2809-512: Was not reached until much later, in the 14th century. Porcelain was also made in Korea and in Japan from the end of the 16th century, after suitable kaolin was located in those countries. It was not made effectively outside East Asia until the 18th century. The study of pottery can help to provide an insight into past cultures. Fabric analysis (see section below), used to analyse the fabric of pottery ,
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