1.
Iran
–
Iran, also known as Persia, officially the Islamic Republic of Iran, is a sovereign state in Western Asia. Comprising a land area of 1,648,195 km2, it is the second-largest country in the Middle East, with 82.8 million inhabitants, Iran is the worlds 17th-most-populous country. It is the country with both a Caspian Sea and an Indian Ocean coastline. The countrys central location in Eurasia and Western Asia, and its proximity to the Strait of Hormuz, Tehran is the countrys capital and largest city, as well as its leading economic and cultural center. Iran is the site of to one of the worlds oldest civilizations, the area was first unified by the Iranian Medes in 625 BC, who became the dominant cultural and political power in the region. The empire collapsed in 330 BC following the conquests of Alexander the Great, under the Sassanid Dynasty, Iran again became one of the leading powers in the world for the next four centuries. Beginning in 633 AD, Arabs conquered Iran and largely displaced the indigenous faiths of Manichaeism and Zoroastrianism by Islam, Iran became a major contributor to the Islamic Golden Age that followed, producing many influential scientists, scholars, artists, and thinkers. During the 18th century, Iran reached its greatest territorial extent since the Sassanid Empire, through the late 18th and 19th centuries, a series of conflicts with Russia led to significant territorial losses and the erosion of sovereignty. Popular unrest culminated in the Persian Constitutional Revolution of 1906, which established a monarchy and the countrys first legislative body. Following a coup instigated by the U. K. Growing dissent against foreign influence and political repression led to the 1979 Revolution, Irans rich cultural legacy is reflected in part by its 21 UNESCO World Heritage Sites, the third-largest number in Asia and 11th-largest in the world. Iran is a member of the UN, ECO, NAM, OIC. Its political system is based on the 1979 Constitution which combines elements of a democracy with a theocracy governed by Islamic jurists under the concept of a Supreme Leadership. A multicultural country comprising numerous ethnic and linguistic groups, most inhabitants are Shia Muslims, the largest ethnic groups in Iran are the Persians, Azeris, Kurds and Lurs. Historically, Iran has been referred to as Persia by the West, due mainly to the writings of Greek historians who called Iran Persis, meaning land of the Persians. As the most extensive interactions the Ancient Greeks had with any outsider was with the Persians, however, Persis was originally referred to a region settled by Persians in the west shore of Lake Urmia, in the 9th century BC. The settlement was then shifted to the end of the Zagros Mountains. In 1935, Reza Shah requested the international community to refer to the country by its native name, opposition to the name change led to the reversal of the decision, and Professor Ehsan Yarshater, editor of Encyclopædia Iranica, propagated a move to use Persia and Iran interchangeably
2.
Metropolitan Museum of Art
–
The Metropolitan Museum of Art, colloquially the Met, is located in New York City and is the largest art museum in the United States, and is among the most visited art museums in the world. Its permanent collection contains two million works, divided among seventeen curatorial departments. The main building, on the edge of Central Park along Manhattans Museum Mile, is by area one of the worlds largest art galleries. A much smaller second location, The Cloisters at Fort Tryon Park in Upper Manhattan, contains a collection of art, architecture. On March 18,2016, the museum opened the Met Breuer museum at Madison Avenue in the Upper East Side, it extends the museums modern, the Met maintains extensive holdings of African, Asian, Oceanian, Byzantine, Indian, and Islamic art. The museum is home to collections of musical instruments, costumes and accessories, as well as antique weapons. Several notable interiors, ranging from first-century Rome through modern American design, are installed in its galleries, the Metropolitan Museum of Art was founded in 1870. The founders included businessmen and financiers, as well as leading artists and thinkers of the day and it opened on February 20,1872, and was originally located at 681 Fifth Avenue. The Met maintains extensive holdings of African, Asian, Oceanian, Byzantine, the museum is also home to encyclopedic collections of musical instruments, costumes and accessories, and antique weapons and armor from around the world. A number of interiors, ranging from 1st century Rome through modern American design, are permanently installed in the Mets galleries. In addition to its permanent exhibitions, the Met organizes and hosts traveling shows throughout the year. The director of the museum is Thomas P. Campbell, a long-time curator and it was announced on February 28th,2017 that Campbell will be stepping down as the Mets director and CEO, effective June. On March 1st,2017 the BBC reported that Daniel Weiss shall be the acting CEO until a replacement is found, Beginning in the late 19th century, the Met started to acquire ancient art and artifacts from the Near East. From a few tablets and seals, the Mets collection of Near Eastern art has grown to more than 7,000 pieces. The highlights of the include a set of monumental stone lamassu, or guardian figures. The Mets Department of Arms and Armor is one of the museums most popular collections. Among the collections 14,000 objects are many pieces made for and used by kings and princes, including armor belonging to Henry VIII of England, Henry II of France, Rockefeller donated his more than 3, 000-piece collection to the museum. The Mets Asian department holds a collection of Asian art, of more than 35,000 pieces, the collection dates back almost to the founding of the museum, many of the philanthropists who made the earliest gifts to the museum included Asian art in their collections
3.
Ash glaze
–
Ash glazes are ceramic glazes made from the ash of various kinds of wood or straw. They have historically been important in East Asia, especially Chinese pottery, Korean pottery, many traditionalist East Asian potteries still use ash glazing, and it has seen a large revival in studio pottery in the West and East. Some potters like to achieve random effects by setting up the kiln so that ash created during firing falls onto the pots, otherwise the ash is mixed with water, and often clay, and applied as a paste. Ash glazing began around 1500 BC, in China during the Shang Dynasty, around 1000 BC, the Chinese apparently realized that the ash covering the pieces was causing the glaze so they started adding the ash as a glaze before the pot went into the kiln. Ash glaze was the first glaze used in East Asia, and contained only ash, clay, the ceramic flux in ash glazes is calcium oxide, commonly known as quicklime, and ash glazes are part of the lime glaze family, not all of which use ash. In some ash glazes extra lime was added to the ash, a relatively high temperature of around 1170 °C is required, high enough to make the body into stoneware or porcelain. The glaze has glasslike and pooling characteristics which puts emphasis on the texture of the piece being glazed. When the glaze is made up of wood ash, the final result is mostly dark brown to green. The pots with these glazes resemble the earth in color and texture, rice-straw ash glaze produces an opaque creamy-white glaze, it is high in silica. If the ash is very thick, there may be sufficient phosphorus to give an opalescent blue, natural ash glaze from ash falling in the kiln tends to collect thickly on the shoulders of typical shapes of storage jar, and begin to drip down the walls of the vessel. This effect might be aided by tying plaits of straw around the shoulders before placing in the kiln, to create the ash, the material needs to burn completely in a kiln. Wood-ash is around 1% the mass of the wood, though some kinds of straw leave ash at a much higher percentage of the original weight. Therefore, a lot of wood or straw is necessary to produce the ash, the ash is then put through a sieve to eliminate the excess clumps from the ash. At this point artists can process the ash further to create a uniform mixture or leave it unprocessed so there are more random final results. To process the ash, water is first added to the mixture, the solution is drained and dried and the result is ash containing less harmful chemicals like some soluble alkalis. A wide range of plants have been used, and their chemical compositions can give very different effects. Wood ash is made up of calcium carbonate, which is used in many glaze recipes. The ash also contains carbonate, phosphates, and other metals, however, the ratio of these chemicals depend on the location, soil
4.
Vitreous enamel
–
Vitreous enamel, also called porcelain enamel, is a material made by fusing powdered glass to a substrate by firing, usually between 750 and 850 °C. The powder melts, flows, and then hardens to a smooth, durable vitreous coating on metal, so in technical terms fired enamelware is an integrated layered composite of glass and metal. Enamelling is an old and widely adopted technology, for most of its history mainly used in jewelry, enamelled and enamelling are the preferred spellings in British English, while enameled and enameling are preferred in American English. The term enamel is most often restricted to work on metal, enamelled glass is also called painted, and overglaze decoration to pottery is often called enamelling. The word enamel comes from the Old High German word smelzan via the Old French esmail, or from a Latin word smaltum, used as a noun, an enamel is usually a small decorative object coated with enamel. Since the 19th century the term also to industrial materials and many metal consumer objects, such as some cooking vessels, dishwashers, laundry machines, sinks. The ancient Egyptians applied enamels to stone objects, pottery, and sometimes jewellery, the ancient Greeks, Celts, Georgians, and Chinese also used enamel on metal objects. Enamel powder could be produced in two ways, either by powdering coloured glass, or by mixing colourless glass powder with pigments such as a metallic oxide, designs were either painted freehand or over the top of outline incisions, and the technique probably originated in metalworking. Once painted, enamelled glass vessels needed to be fired at a high enough to melt the applied powder. Ancient Persians used this method for colouring and ornamenting the surface of metals by fusing over it brilliant colours that are decorated in an intricate design and called it Meenakari. Gold has been used traditionally for Meenakari Jewellery as it holds the enamel better, lasts longer, initially, the work of Meenakari often went unnoticed as this art was traditionally used as a backing for the famous kundan or stone-studded jewellery. This also allowed the wearer to reverse the jewellery as also promised a special joy in the secret of the hidden design, the Byzantine enamel style was widely adopted by the barbarian peoples of Migration Period northern Europe. The Byzantines then began to use cloisonné more freely to create images, the champlevé technique was considerably easier and very widely practiced in the Romanesque period. In Gothic art the finest work is in basse-taille and ronde-bosse techniques, from either Byzantium or the Islamic world, the cloisonné technique reached China in the 13-14th centuries. The first written reference to cloisonné is in a book from 1388, cloisonné remained very popular in China until the 19th century and is still produced today. Starting from the century, the Japanese also produced large quantities of very high technical quality. A resurgence in enamel-based art took place near the end of the 20th century in the Soviet Union, led by artists like Alexei Maximov, in Australia, abstract artist Bernard Hesling brought the style into prominence with his variously sized steel plates. Enamel was first applied commercially to sheet iron and steel in Austria, industrialization increased as the purity of raw materials increased and costs decreased
5.
Ceramic
–
A ceramic is an inorganic, non-metallic, solid material comprising metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds. This article gives an overview of ceramic materials from the point of view of materials science, the crystallinity of ceramic materials ranges from highly oriented to semi-crystalline, vitrified, and often completely amorphous. Most often, fired ceramics are either vitrified or semi-vitrified as is the case with earthenware, stoneware, varying crystallinity and electron consumption in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators. With such a range of possible options for the composition/structure of a ceramic, the breadth of the subject is vast. Many composites, such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family. The earliest ceramics made by humans were pottery objects or figurines made from clay, either by itself or mixed with materials like silica, hardened, sintered. Later ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, ceramics now include domestic, industrial and building products, as well as a wide range of ceramic art. In the 20th century, new materials were developed for use in advanced ceramic engineering. The word ceramic comes from the Greek word κεραμικός, of pottery or for pottery, from κέραμος, potters clay, tile, the earliest known mention of the root ceram- is the Mycenaean Greek ke-ra-me-we, workers of ceramics, written in Linear B syllabic script. The word ceramic may be used as an adjective to describe a material, product or process, or it may be used as a noun, either singular, or, more commonly, as the plural noun ceramics. A ceramic material is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material, some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, weak in shearing and they withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C. Glass is often not considered a ceramic because of its amorphous character. However, glassmaking involves several steps of the process and its mechanical properties are similar to ceramic materials. Traditional ceramic raw materials include minerals such as kaolinite, whereas more recent materials include aluminium oxide. The modern ceramic materials, which are classified as advanced ceramics, include silicon carbide, both are valued for their abrasion resistance, and hence find use in applications such as the wear plates of crushing equipment in mining operations. Advanced ceramics are used in the medicine, electrical, electronics industries. Crystalline ceramic materials are not amenable to a range of processing
6.
Earthenware
–
Earthenware is glazed or unglazed nonvitreous pottery which has normally been fired below 1200°C. Porcelain, bone china and stoneware, all fired at high temperatures to vitrify, are the main other important types of pottery. Pit fired earthenware dates back to as early as 29, 000–25,000 BCE, outside East Asia, porcelain was manufactured only from the 18th century, and then initially as an expensive luxury. Earthenware, when fired, is opaque and non-vitreous, soft, the Combined Nomenclature of the European Communities describes it as being made of selected clays sometimes mixed with feldspars and varying amounts of other minerals and white or light-colored. Generally, earthenware bodies exhibit higher plasticity than most whiteware bodies and hence are easier to shape by RAM press, due to its porosity, earthenware, with a water absorption of 5-8%, must be glazed to be watertight. Earthenware has lower mechanical strength than bone china, porcelain or stoneware, darker-colored terracotta earthenwares, typically orange or red, due to a comparatively high content of iron oxide are widely used for flower pots, tiles and some decorative and oven wares. A general body formulation for contemporary earthenware is 25% kaolin, 25% ball clay, 35% quartz and 15% feldspar. Modern earthenware may be fired to temperatures between 1,000 and 1,150 °C and glost-fired to between 950 to 1,050 °C, the usual practice in factories and some studio potteries. Some studio potters follow the practice, with a low-temperature bisque firing. The firing schedule will be determined by the raw materials used, historically, such high temperatures were unattainable in most cultures and periods until modern times, though Chinese ceramics were far ahead of other cultures in this respect. Earthenware can be produced at firing temperatures as low as 600 °C, much historical pottery was fired somewhere around 800 °C, giving a wide margin of error where there was no precise way of measuring temperature, and very variable conditions within the kiln. After firing most earthenware bodies will be colored white, buff or red, for red earthenware, the firing temperature affects the color of the clay body. Lower temperatures produce a red terracotta color, higher temperatures will make the clay brown or even black. Higher firing temperatures may cause earthenware to bloat, an Introduction to the Technology Of Pottery. Whitewares, Production, Testing And Quality Control, the Potters Dictionary of Materials and Techniques. A & C Black Publishers Limited, London, England, Third Edition,1991
7.
Porosity
–
Porosity or void fraction is a measure of the void spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0 and 100%. Strictly speaking, some measure the accessible void, the total amount of void space accessible from the surface. There are many ways to test porosity in a substance or part, the term porosity is used in multiple fields including pharmaceutics, ceramics, metallurgy, materials, manufacturing, earth sciences, soil mechanics and engineering. Void fraction usually varies from location to location in the flow channel and it fluctuates with time and its value is usually time averaged. In separated flow, it is related to flow rates of the gas and the liquid phase. It is defined by the ratio, ϕ = V V V T where VV is the volume of void-space and VT is the total or bulk volume of material, both the mathematical symbols ϕ and n are used to denote porosity. Porosity is a fraction between 0 and 1, typically ranging from less than 0.01 for solid granite to more than 0.5 for peat and it may also be represented in percent terms by multiplying the fraction by 100. The porosity of a rock, or sedimentary layer, is an important consideration when attempting to evaluate the potential volume of water or hydrocarbons it may contain. Sedimentary porosity is a function of many factors, including but not limited to, rate of burial, depth of burial, the nature of the connate fluids. The principal complication is that there is not a direct proportionality between porosity and hydraulic conductivity but rather an inferred proportionality, there is a clear proportionality between pore throat radii and hydraulic conductivity. Also, there tends to be a proportionality between pore throat radii and pore volume, if the proportionality between pore throat radii and porosity exists then a proportionality between porosity and hydraulic conductivity may exist. Well sorted materials have higher porosity than similarly sized poorly sorted materials, for tables of common porosity values for earth materials, see the further reading section in the Hydrogeology article. Consolidated rocks potentially have more complex dual porosities, as compared with alluvial sediment and this can be split into connected and unconnected porosity. Connected porosity is more easily measured through the volume of gas or liquid that can flow into the rock, porosity is the ratio of pore volume to its total volume. Porosity is controlled by, rock type, pore distribution, cementation, diagenetic history, porosity is not controlled by grain size, as the volume of between-grain space is related only to the method of grain packing. Rocks normally decrease in porosity with age and depth of burial, tertiary age Gulf Coast sandstones are in general more porous than Cambrian age sandstones. There are exceptions to this rule, usually because of the depth of burial and thermal history, porosity of surface soil typically decreases as particle size increases. This is due to soil formation in finer textured surface soils when subject to soil biological processes
8.
Stoneware
–
Earthenware is glazed or unglazed nonvitreous pottery which has normally been fired below 1200°C. Porcelain, bone china and stoneware, all fired at high temperatures to vitrify, are the main other important types of pottery. Pit fired earthenware dates back to as early as 29, 000–25,000 BCE, outside East Asia, porcelain was manufactured only from the 18th century, and then initially as an expensive luxury. Earthenware, when fired, is opaque and non-vitreous, soft, the Combined Nomenclature of the European Communities describes it as being made of selected clays sometimes mixed with feldspars and varying amounts of other minerals and white or light-colored. Generally, earthenware bodies exhibit higher plasticity than most whiteware bodies and hence are easier to shape by RAM press, due to its porosity, earthenware, with a water absorption of 5-8%, must be glazed to be watertight. Earthenware has lower mechanical strength than bone china, porcelain or stoneware, darker-colored terracotta earthenwares, typically orange or red, due to a comparatively high content of iron oxide are widely used for flower pots, tiles and some decorative and oven wares. A general body formulation for contemporary earthenware is 25% kaolin, 25% ball clay, 35% quartz and 15% feldspar. Modern earthenware may be fired to temperatures between 1,000 and 1,150 °C and glost-fired to between 950 to 1,050 °C, the usual practice in factories and some studio potteries. Some studio potters follow the practice, with a low-temperature bisque firing. The firing schedule will be determined by the raw materials used, historically, such high temperatures were unattainable in most cultures and periods until modern times, though Chinese ceramics were far ahead of other cultures in this respect. Earthenware can be produced at firing temperatures as low as 600 °C, much historical pottery was fired somewhere around 800 °C, giving a wide margin of error where there was no precise way of measuring temperature, and very variable conditions within the kiln. After firing most earthenware bodies will be colored white, buff or red, for red earthenware, the firing temperature affects the color of the clay body. Lower temperatures produce a red terracotta color, higher temperatures will make the clay brown or even black. Higher firing temperatures may cause earthenware to bloat, an Introduction to the Technology Of Pottery. Whitewares, Production, Testing And Quality Control, the Potters Dictionary of Materials and Techniques. A & C Black Publishers Limited, London, England, Third Edition,1991
9.
Porcelain
–
Porcelain /ˈpɔːrsəlᵻn, ˈpɔːrslᵻn/ is a ceramic material made by heating materials, generally including kaolin, in a kiln to temperatures between 1,200 and 1,400 °C. Porcelain was first developed in China around 2,000 years ago, then spread to other East Asian countries, and finally Europe. It combines well with both glazes and paint, and can be modelled very well, allowing a range of decorative treatments in tablewares, vessels. It also has uses in technology and industry. The European name, porcelain in English, come from the old Italian porcellana because of its resemblance to the translucent surface of the shell, Porcelain is also referred to as china or fine china in some English-speaking countries, as it was first seen in imports from China. Porcelain has been described as being completely vitrified, hard, impermeable, white or artificially coloured, translucent, however, the term porcelain lacks a universal definition and has been applied in a very unsystematic fashion to substances of diverse kinds which have only certain surface-qualities in common. Terms such as porcellaneous or near-porcelain may be used in such cases, a high proportion of modern porcelain is made of the variant bone china. Kaolin is the material from which porcelain is made, even though clay minerals might account for only a small proportion of the whole. The word paste is an old term for both the unfired and fired material, a more common terminology these days for the unfired material is body, for example, when buying materials a potter might order an amount of porcelain body from a vendor. The composition of porcelain is highly variable, but the mineral kaolinite is often a raw material. Other raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse, the clays used are often described as being long or short, depending on their plasticity. Long clays are cohesive and have high plasticity, short clays are cohesive and have lower plasticity. Clays used for porcelain are generally of lower plasticity and are shorter than many other pottery clays and they wet very quickly, meaning that small changes in the content of water can produce large changes in workability. Thus, the range of content within which these clays can be worked is very narrow. The following section provides information on the methods used to form, decorate, finish, glaze. Many types of glaze, such as the iron-containing glaze used on the wares of Longquan, were designed specifically for their striking effects on porcelain. Porcelain wares may be decorated under the glaze using pigments that include cobalt and copper or over the glaze using coloured enamels. Like many earlier wares, modern porcelains are often biscuit-fired at around 1,000 °C, coated with glaze, another early method is once-fired where the glaze is applied to the unfired body and the two fired together in a single operation
10.
Pottery
–
Pottery is the craft of making ceramic material into pots or potterywares using mud. Major types of potterywares include earthenware, stoneware and porcelain, the place where such wares are made by a potter is also called a pottery. Early Neolithic pottery have found in places such as Jomon Japan. A clay body can be decorated before or after firing, however, prior to shaping processes. Kneading helps to ensure an even moisture content throughout the body, air trapped within the clay body needs to be removed. This is called de-airing and can be accomplished either by a called a vacuum pug or manually by wedging. Wedging can also produce an even moisture content. Once a clay body has been kneaded and de-aired or wedged, after shaping, it is dried and then fired. Clay ware takes on varying physical characteristics during the making of pottery, at sufficient moisture content, bodies at this stage are in their most plastic form. Leather-hard refers to a body that has been dried partially. At this stage the clay object has approximately 15% moisture content, clay bodies at this stage are very firm and only slightly pliable. Trimming and handle attachment often occurs at the leather-hard state, bone-dry refers to clay bodies when they reach a moisture content at or near 0%. It is now ready to be bisque fired, bisque refers to the clay after the object is shaped to the desired form and fired in the kiln for the first time, known as bisque fired or biscuit fired. This firing changes the body in several ways. Mineral components of the body will undergo chemical changes that will change the colour of the clay. Glaze fired is the stage of some pottery making. A glaze may be applied to the form and the object can be decorated in several ways. After this the object is glazed fired, which causes the material to melt
11.
Tile
–
A tile is a manufactured piece of hard-wearing material such as ceramic, stone, metal, or even glass, generally used for covering roofs, floors, walls, showers, or other objects such as tabletops. Alternatively, tile can sometimes refer to units made from lightweight materials such as perlite, wood. In another sense, a tile is a tile or similar object. The word is derived from the French word tuile, which is, in turn, from the Latin word tegula, Tiles are often used to form wall and floor coverings, and can range from simple square tiles to complex mosaics. Tiling stone is marble, onyx, granite or slate. Thinner tiles can be used on walls than on floors, which require more durable surfaces that will resist impacts, the earliest evidence of glazed brick is the discovery of glazed bricks in the Elamite Temple at Chogha Zanbil, dated to the 13th century BC. Glazed and colored bricks were used to make low reliefs in Ancient Mesopotamia, most famously the Ishtar Gate of Babylon, now reconstructed in Berlin. Mesopotamian craftsmen were imported for the palaces of the Persian Empire such as Persepolis, tiling was used in the second century by the Sinhalese kings of ancient Sri Lanka, using smoothed and polished stone laid on floors and in swimming pools. Historians consider the techniques and tools for tiling as well advanced, evidenced by the fine workmanship, tiling from this period can be seen Ruwanwelisaya and Kuttam Pokuna in the city of Anuradhapura. The Achaemenid Empire decorated buildings with glazed tiles, including Darius the Greats palace at Susa. The succeeding Sassanid Empire used tiles patterned with geometric designs, flowers, plants, birds and human beings, early Islamic mosaics in Iran consist mainly of geometric decorations in mosques and mausoleums, made of glazed brick. Typical turquoise tiling becomes popular in 10th-11th century and is used mostly for Kufic inscriptions on mosque walls, seyyed Mosque in Isfahan, Dome of Maraqeh and the Jame Mosque of Gonabad are among the finest examples. The dome of Jame Atiq Mosque of Qazvin is also dated to this period, the golden age of Persian tilework began during the reign the Timurid Empire. In the moraq technique, single-color tiles were cut into small geometric pieces, after hardening, these panels were assembled on the walls of buildings. But the mosaic was not limited to flat areas, Tiles were used to cover both the interior and exterior surfaces of domes. Prominent Timurid examples of this include the Jame Mosque of Yazd, Goharshad Mosque, the Madrassa of Khan in Shiraz. Other important tile techniques of time include girih tiles, with their characteristic white girih. Mihrabs, being the points of mosques, were usually the places where most sophisticated tilework was placed
12.
Architectural terracotta
–
In the latter sense unglazed architectural terracotta became fashionable as an architectural ceramic construction material in England in the 1860s, and in the United States in the 1870s. Glazed architectural terracotta was developed a little later, both were generally used as a decorative skin to cover or supplement brick and tiles of similar colour in late Victorian buildings. Terracotta had been used architecturally before this in Germany from 1824 by Karl Friedrich Schinkel, edmund Sharpe designed and oversaw the construction of the first church built almost exclusively of the material, St Stephen and All Martyrs Church, Lever Bridge in Bolton, erected 1842–45. Henry Cole, secretary to the Science and Arts Department of the UK adopted terracotta for the building which is now the Victoria and Albert Museum and then the Royal Albert Hall, alfred Waterhouse used it in his designs when in business in Manchester from 1853 and London from 1865. He used a combination of buff and blue-grey terracotta in his Natural History Museum in London, the colour of terracotta varies with the source of the clay. In Britain, London clay gives a pink or buff colour. Terracotta had the advantage of being cheap and light and it was adaptable to mass-production techniques for stock shapes, although the plaster moulds had a limited capability for re-use. Additionally it could be worked by craftsmen to make custom-sculptured adornments. It was accepted as a material by the Arts and Crafts movement because despite seeming a mass-produced material it was handmade and it had a manufacture time of about eight weeks and each piece had to be made over-size to allow for shrinkage as the clay body dried. To avoid cracking the pieces had to be quite thin and they were filled with concrete as they were applied to buildings. The disadvantage of terracotta, apart from its rather uniform colour in a district, was that it was not easy to keep clean. Bricks, Tiles and Terracotta, An Exhibition on one of the industries of the Wrexham area. James W P Campbell & Will Pryce, Brick, A World History, ISBN 0-500-34195-8 Stratton, the Terracotta Revival, Building Innovation and the Image of the Industrial City in Britain and North America. Article on terracotta in Victorian and Edwardian Terracotta Buildings Understanding and Conserving Terracotta - Dr Michael Stratton Bolton Museums
13.
Glazed architectural terra-cotta
–
Glazed architectural terra-cotta is a ceramic masonry building material used as a decorative skin. It has been popular in the United States from the late 19th century until the 1930s and it is the glazed version of architectural terra-cotta, the material in both its glazed and unglazed versions is sturdy and relatively inexpensive, and can be molded into richly ornamented detail. Glazed terra-cotta played a significant role in architectural styles such as the Chicago School, buildings incorporating glazed terra-cotta include the Woolworth Building in New York City and the Wrigley Building in Chicago. Glazed architectural terra-cotta offered a modular, varied and relatively inexpensive approach to wall and it was particularly adaptable to vigorous and rich ornamental detailing. It was created by Luca della Robbia, and was used in most of his works, terra-cotta is an enriched molded clay brick or block. It was usually hollow cast in blocks which were open in the back, webbing substantially strengthened the hollow blocks with minimal weight increase. The blocks were finished with a glaze, with a wash or an aqueous solution of metal salts. Late 19th century advertising for the material promoted the durable, impervious and it could accommodate subtle nuances of modeling, texture and color. Compared to stone, it was easier to handle, quickly set, the cost of producing the blocks, when compared to carving stone, was a considerable saving, especially when casts were used in a modular fashion—that is, used repeatedly. It never needed paint, and periodic washings restored its appearance, variations in the color and pattern of the glaze could make it look like granite or limestone, this flexibility helped make it attractive for architects. Four major types of terra-cotta were widely used Brownstone was the earliest type, fireproof was developed as a direct result of the growth of the high rise building in America. Cheap, light and fireproof, the hollow blocks were ideally suited to span the I-beam members in floor, wall. Certain varieties are still in production today, veneer was developed during the 1930s and is still used today. Unlike traditional architectural terra-cotta, ceramic veneer is not hollow cast and it is a veneer of glazed ceramic tile which is ribbed on the back like bathroom tile and usually attached to a grid of metal ties which have been anchored to the building. Glazed architectural terra-cotta was the most complex building material developed, the hollow units were hand cast in molds or carved in clay and heavily glazed, then fired. This is the associated with the architecture of Cass Gilbert, Louis Sullivan. It was the last exclusive manufacturer of architectural terra cotta by the time it ceased production in 1966, from its founding in time to rebuild the fire-ravished city of Chicago until its closing, it was the major producer of architectural glazed terra cotta in North America. Guastavino tile was used in places, including the Bridgemarket under the Manhattan side of the Queensboro Bridge
14.
Overhead power line
–
An overhead power line is a structure used in electric power transmission and distribution to transmit electrical energy along large distances. It consists of one or more conductors suspended by towers or poles, since most of the insulation is provided by air, overhead power lines are generally the lowest-cost method of power transmission for large quantities of electric energy. Towers for support of the lines are made of wood, steel or aluminum, concrete, the bare wire conductors on the line are generally made of aluminum, though some copper wires are used in medium-voltage distribution and low-voltage connections to customer premises. Today overhead lines are operated at voltages exceeding 765,000 volts between conductors, with even higher voltages possible in some cases. Medium voltage – between 1000 volts and 69 kV, used for distribution in urban and rural areas, high voltage, used for sub-transmission and transmission of bulk quantities of electric power and connection to very large consumers. Extra high voltage – over 230 kV, up to about 800 kV, used for long distance, ultra high voltage – higher than 800 kV. Structures for overhead lines take a variety of shapes depending on the type of line, tubular steel poles are typically used in urban areas. High-voltage lines are carried on lattice-type steel towers or pylons. For remote areas, aluminum towers may be placed by helicopters, concrete poles have also been used. Poles made of reinforced plastics are available, but their high cost restricts application. Each structure must be designed for the loads imposed on it by the conductors, the weight of the conductor must be supported, as well as dynamic loads due to wind and ice accumulation, and effects of vibration. Where conductors are in a line, towers need only resist the weight since the tension in the conductors approximately balances with no resultant force on the structure. Flexible conductors supported at their ends approximate the form of a catenary, depending on the design criteria for a particular line, semi-flexible type structures may rely on the weight of the conductors to be balanced on both sides of each tower. More rigid structures may be intended to remain standing even if one or more conductors is broken, such structures may be installed at intervals in power lines to limit the scale of cascading tower failures. Foundations for tower structures may be large and costly, particularly if the conditions are poor. Each structure may be stabilized considerably by the use of guy wires to counteract some of the forces applied by the conductors, Power lines and supporting structures can be a form of visual pollution. In some cases the lines are buried to avoid this, but this undergrounding is more expensive, for a single wood utility pole structure, a pole is placed in the ground, then three crossarms extend from this, either staggered or all to one side. The insulators are attached to the crossarms, for an H-type wood pole structure, two poles are placed in the ground, then a crossbar is placed on top of these, extending to both sides
15.
Lead-glazed earthenware
–
Lead-glazed earthenware is one of the traditional types of glazed earthenware, which coat the ceramic body and render it impervious to liquids, as terracotta itself is not. The lead glaze is shiny and transparent after firing, modern materials technology has invented new vitreous glazes that do not fall into these traditional categories. In lead glazes tints provided by impurities render greenish to brownish casts, the Romans used lead glazes for high-quality oil lamps and drinking cups. Lead oxide was the principal flux in the glaze, polychrome effects were obtained by using as coloring agents copper, iron, much of Roman technology was lost in the West, but coarse lead-glazed earthenwares were universal in medieval Europe and in Colonial America. In England, lead-glazed Stamford Ware was produced in Stamford, Lincolnshire as early as the ninth century and it was widely traded across Britain and the near continent. In 16th-century France Bernard Palissy refined lead-glazed earthenware to a high standard, lead-glazed earthenwares in Britain include the Toby jugs, such as those made in the late 18th century by Ralph Wood the Younger at Burslem, Staffordshire
16.
Sancai
–
Sancai is a versatile type of decoration on Chinese pottery mainly using the three colors of brown, green, and a creamy off-white for decoration. It is particularly associated with the Tang Dynasty and its tomb figures, therefore, it is commonly referred to as Chinese, 唐三彩 Tang Sancai in Chinese. Flatware dishes and other vessels were made in the technique as well as figures, the body of sancai ceramics was made of white clay, coated with colored glaze, and fired at a temperature of 800 degrees Celsius. Sancai is a type of lead-glazed earthenware, lead oxide was the principal flux in the glaze, the polychrome effect was obtained by using as coloring agents copper, iron, and less often manganese and cobalt. Sancai follows the development of green-glazed pottery dating back to the Han period, predecessors to the sancai style can also be seen in some Northern Qi ceramic works. Northern Qi tombs have revealed some beautiful artifacts, such as porcellaneous ware with splashed green designs, such a jar has been found in a Northern Qi tomb, which was closed in 576 AD, and is considered as a precursor of the Tang sancai style of ceramics. The sancai technique dates back to the Tang Dynasty, however, the colors of the glazes used to decorate the wares of the Tang Dynasty generally were not limited to three in number. In the West, Tang sancai wares were sometimes referred to as egg-and-spinach by dealers, for their use of green, yellow, Sancai wares were northern wares made using white and buff-firing secondary kaolins and fire clays. At kiln sites located at Tongchuan, Neiqui county in Hebei and Gongxian in Henan, the burial wares were fired at a lower temperature than contemporaneous whitewares. Large figures made for goods in burials, such as the well-known representations of camels and horses, were cast in sections. In some cases, a degree of individuality was imparted to the figurines by hand-carving. Sancai continued to be produced in later periods, very often for large items made for temples, sets of sancai luohan figures up to life-size were often displayed in special luohan halls in temples. Few of these remained in place survived the Cultural Revolution. The Yixian glazed pottery luohans are a Liao dynasty set that is now distributed between various Western museums, and so well known. Unusually, these were constructed around internal supporting iron bars, pairs of large guardian figures flanking shrines were also made. Sancai travelled along the Silk Road, to be extensively used in Syrian, Cypriot. Sancai also became a style in Japanese and other East Asian ceramic arts. In the 1980s and early 1990s reproductions of Tang sancai pieces were sent by the Chinese government to foreign leaders as gifts, at one point there were more than 3,000 factories, mostly tiny and shabby, sprinkled around Luoyang City, cradle of the craft
17.
Victorian majolica
–
This article refers to the two types of earthenware made in 19th century between 1848 and 1900 that are together known as Victorian Majolica. For mainstream pottery with a white glaze painted with coloured enamels. Victorian majolica includes two types of earthenware made in 19th century between 1848 and 19001, Victorian majolica was originated by Mintons, who exhibited at the Great Exhibition of 1851. The Exhibition Catalogue does not use the name Palissy ware that was used in the Minton factory, the debt to the eccentric 16th century potter Bernard Palissy is obvious from its naturalistic plant and animal motifs. Exhibition Catalogue entry Earthenware… Flowerpots, etc.60, a variety of… flowerpots and stands, and garden seats. Exhibition Catalogue entry Tiles, Terra Cotta, and Vases, etc, variety of flowerpots and stands, coloured in the majolica style, etc. The reader will remember that the difference in these wares is that whereas the Palissy ware is coloured by a transparent glaze. The care and taste with which these manufactures have been brought by the Messrs, Minton to their present state of perfection, have been amply rewarded. Within a few days of the opening of the Exhibition all the specimens exhibited had been sold, despite this reminder Mintons Palissy Ware became known as majolica ware, Palissy ware dropped out of use and majolica stuck. In the 1880s, the curators of the South Kensington Museum tried to clear up the confusion by reviving the Italian spelling maiolica with an i instead of a j for Italian tin-glaze, Wedgwood began to manufacture majolica about ten years after Mintons. Wedgwoods glazes and modelling were denser and more formal than Mintons, Wedgwoods majolica included cachepots, jugs, candlesticks, cheese bells, umbrella stands, sardine boxes, plates in naturalistic patterns, bread trays, etc. In Wedgwoods greenware the green glaze emphasizes the low relief patterning, typically of basketwork, Majolica was influenced by the design of the old Cauliflower and Pineapple teapots that had been made by Thomas Whieldon, Wedgwood and other 18th-century Staffordshire potters. Many late 19th-century majolica designs had rustic motifs with backgrounds of basketry and wooden-bound buckets decorated with moulded flowers, birds, fish, handles were made to resemble tree branches, rose stems and twined flowers and leaves. Many potteries responded to the popularity of majolica, the Trent Pottery, George Jones and Sons, made majolica cupids, shells, dolphins, birds, figurines and coral designs in numerous shapes. Their mark was a monogram of the initials G. J. joined together, a beehive bread dish with a cover has a design of wild roses against a background of basketwork and has the Trent Pottery mark. Also flowerpots were made in bright colours and with raised designs of natural flowers, royal Worcester made figurines, shell vases, wall pockets etc. marking most of their output with an impressed crown over rose backstamp, using a distinctive paler blue glaze. William Brownfield made wall pockets, jugs, game pie dishes, some wares were impressed W B. T. Furnival and Sons made jugs and plates with raised oriental designs, which had borders of wickerwork in bold colour and glaze. Their mark, Furnival, is impressed in the ware, edward Steele of Hanley manufactured jugs, flower vases, teapots, dessert services also made majolica and centrepieces with fine colouring
18.
Tin-glazed pottery
–
Tin-glazed pottery is earthenware covered in glaze containing tin oxide which is white, shiny and opaque, usually this provides a background for brightly-painted decoration. It has been important in Islamic and European pottery, but very little used in East Asia, the pottery body is usually made of red or buff colored earthenware and the white glaze imitated Chinese porcelain. The makers of Italian tin-glazed pottery from the late Renaissance blended oxides to produce detailed, from there it spread to Egypt, Persia and Spain before reaching Italy in the Renaissance, Holland in the 16th century and England, France and other European countries shortly after. The rise in the cost of tin oxide during the First World War led to its substitution by zirconium compounds in the glaze. Tin-glazed pottery of different periods and styles is known by different names, the pottery from Muslim Spain is known as Hispano-Moresque ware. The decorated tin-glaze of Renaissance Italy is called maiolica, sometimes pronounced majolica by English speakers, when the technique was taken up in the Netherlands it became known as delftware as much of it was made in the town of Delft. Dutch potters brought it to England in around 1600 and wares produced there are known as English delftware or galleyware, in France it was known as faience. During the Renaissance, the term maiolica was adopted for Italian-made luster pottery copying Spanish examples, in the late 18th century, old Italian maiolica became popular among the British, who referred to it by the anglicized pronunciation majolica. The Minton pottery copied it and applied the term majolica ware to their product, at the Great Exhibition of 1851, Minton launched the colorful lead-glazed earthenware which they called Palissy ware soon also to become known as majolica. So now we have two distinct products with the same name, for the article about 19th century lead-glazed earthenware, see Victorian majolica W. B. The term maiolica is sometimes applied to modern tin-glazed ware made by studio potters, the Moors introduced tin-glazed pottery to Spain after the conquest of 711. With the Spanish conquest of Mexico, tin-glazed pottery came to be produced in the Valley of Mexico as early as 1540, although the Moors were expelled from Spain in the early 17th century, the Hispano-Moresque style survived in the province of Valencia. Later wares usually have a coarse reddish-buff body, dark blue decoration, such archaic wares are sometimes dubbed proto-maiolica. During the later 14th century, the palette of colors was expanded from the traditional manganese purple and copper green to embrace cobalt blue, antimony yellow. Sgraffito wares were produced, in which the white tin-oxide slip was decoratively scratched to produce a design from the revealed body of the ware. Refined production of tin-glazed earthenware made for more local needs was concentrated in central Italy from the later 13th century. The city itself declined in importance in the half of the 15th century. Italian cities encouraged the start of a new industry by offering tax relief, citizenship, monopoly rights
19.
Ancient Near East
–
The ancient Near East is studied in the fields of Near Eastern archaeology and ancient history. The ancient Near East is considered one of the cradles of civilization and it also saw the creation of the first writing system and law codes, early advances that laid the foundations of astronomy and mathematics, and the invention of the wheel. During the period, states became increasingly large, until by the end the region was controlled by military empires who had conquered a number of different cultures. The phrase ancient Near East utilizes the 19th-century distinction between Near East and Far East as global regions of interest to the British Empire, the distinction began during the Crimean War. The two theatres were described by the statesmen and advisors of the British Empire as the Near East, shortly, they were to share the stage with Middle East, which came to prevail in the 20th century and continues in modern times. Meanwhile, ancient Near East had become distinct, the Near East ruled by the Ottoman Empire ranged from Vienna to the north to the tip of the Arabian Peninsula to the south, from Egypt in the west to the borders of Iraq in the east. The 19th-century archaeologists added Iran to their definition, which was never under the Ottomans, but they excluded all of Europe and, generally, Egypt, which had parts in the empire. Ancient Near East periodization is the attempt to categorize or divide time into discrete named blocks, or eras, the result is a descriptive abstraction that provides a useful handle on Near East periods of time with relatively stable characteristics. Named after the Sumerian city of Uruk, this saw the emergence of urban life in Mesopotamia. It was followed by the Sumerian civilization, the late Uruk period saw the gradual emergence of the cuneiform script and corresponds to the Early Bronze Age. Sumer, located in southern Mesopotamia, is the earliest known civilization in the world, the Akkadian Empire, founded by Sargon the Great, lasted from the 24th to the 21st century BC, and was regarded by many as the worlds first Empire. The Akkadians eventually fragmented into Assyria and Babylonia, Ancient Elam lay to the east of Sumer and Akkad, in the far west and southwest of modern-day Iran, stretching from the lowlands of Khuzestan and Ilam Province. In the Old Elamite period, c.3200 BC, it consisted of kingdoms on the Iranian plateau, centered on Anshan, and from the mid-2nd millennium BC, it was centered on Susa in the Khuzestan lowlands. Elam was absorbed into the Assyrian Empire in the 9th to 7th centuries BC, however, the Proto-Elamite civilization existed from c.3200 BC to 2700 BC, when Susa, the later capital of the Elamites, began to receive influence from the cultures of the Iranian plateau. In archaeological terms, this corresponds to the late Banesh period and this civilization is recognized as the oldest in Iran and was largely contemporary with its neighbour, the Sumerian civilization. The Proto-Elamite script is an Early Bronze Age writing system briefly in use for the ancient Elamite language before the introduction of Elamite Cuneiform, the Amorites were a nomadic Semitic people who occupied the country west of the Euphrates from the second half of the 3rd millennium BC. In the earliest Sumerian sources, beginning about 2400 BC, the land of the Amorites is associated with the West, including Syria and Canaan and they ultimately settled in Mesopotamia, ruling Isin, Larsa, and later Babylon. Assyria, after enduring a period of Mitanni domination, emerged as a great power from the accession of Ashur-uballit I in 1365 BC to the death of Tiglath-Pileser I in 1076 BC
20.
Islamic pottery
–
Medieval Islamic pottery occupied a geographical position between Chinese ceramics, then the unchallenged leaders of Eurasian production, and the pottery of the Byzantine Empire and Europe. The era of Islamic pottery started around 622, from 633, Muslim armies moved rapidly towards Persia, Byzantium, Mesopotamia, Anatolia, Egypt and later Andalusia. The early history of Islamic pottery remains somewhat obscure and speculative as little evidence has survived, apart from tiles which escaped destruction due to their use in architectural decoration of buildings and mosques, much early medieval pottery vanished. The Muslim world inherited significant pottery industries in Mesopotamia, Persia, Egypt, North Africa, indeed, the origin of glazed pottery has been traced to Egypt where it was first introduced during the fourth millennium BCE. However most of these traditions made heavy use of figurative decoration, a distinct Muslim style in pottery was not firmly established until the 9th century in Iraq, Syria and Persia. During this period pieces mainly used white tin-glaze, information on earlier periods is very limited. This is largely due to the lack of surviving specimens in good condition which also limits the interest in the study of ceramics of these periods, archaeological excavations carried out in Jordan uncovered only a few examples from the Umayyad period, mostly unglazed vessels from Khirbat Al-Mafjar. In the East, evidence shows that a production centre was set up in Samarkand under the Samanid dynasty who ruled this region, the most highly regarded technique of this centre is the use of calligraphy in the decoration of vessels. During the Abbasid dynasty pottery production gained momentum, largely using tin glazes mostly in the form of opaque white glaze, some historians, such as Arthur Lane, attribute the rise of such industry to Chinese influence. Evidence from Muslim manuscripts, such as Akhbar al-Sin wa al-Hind and Ibn Kurdadhbih’s Book of Roads and Provinces, according to Lane, the influence of Chinese pottery progressed in three main phases. The first contact with China took place in 751 when the Arabs defeated the Chinese at the Battle of Talas and it has been argued that imprisoned Chinese potters and paper makers could have taught the Muslims the art of pottery and paper-making. In 800’s Chinese stoneware and porcelain reached the Abbasids, the second phase took place in the twelfth and thirteenth centuries, a period noted for the decline of pottery industry following the fall of the Seljuk dynasty. This period also saw the invasion of the Mongols who brought Chinese pottery traditions, the influence of ceramics from the Tang Dynasty can be seen on lustrewares, produced by Mesopotamian potters, and on some early white wares excavated at Samarra. Ceramics from this period were excavated at Nishapur and Samarkand and these were less successful than those of Korean pottery, but eventually were able to provide attractive local competition to Chinese imports. Chinese production could adapt to the preferences of foreign markets, larger celadon dishes than the Chinese market wanted were favoured for serving princely banquets in the Middle East, celadon wares were believed there to have the ability to detect poison, by sweating or breaking. The Islamic market was especially important in the early years of Chinese blue and white porcelain. This style of ornament was then confined to blue and white, the start of the Ming dynasty was quickly followed by a decree of 1368, forbidding trade with foreign countries. Often Islamic production imitated not the latest Chinese styles, but those of the late Yuan, in turn, Chinese potters began in the early 16th century to produce some items in overtly Islamic styles, including jumbled inscriptions in Arabic
21.
Faience
–
Faience or faïence is the conventional name in English for fine tin-glazed pottery on a delicate pale buff earthenware body. It is originally associated by French speakers with wares exported from Faenza in northern Italy. The invention of a white pottery glaze suitable for painted decoration, the invention seems to have been made in Iran or the Middle East before the ninth century. A kiln capable of producing temperatures exceeding 1,000 °C was required to achieve this result, the result of millennia of refined pottery-making traditions. The term is now used for a variety of pottery from several parts of the world, including many types of European painted wares. Technically, lead-glazed earthenware, such as the French sixteenth-century Saint-Porchaire ware, does not properly qualify as faience, semi-vitreous stoneware may be glazed like faience. However, this material is not pottery at all, containing no clay, the Metropolitan Museum of Art displays a faience hippopotamus from Meir, Egypt, dated to Dynasty 12, ca. Examples of ancient faience are also found in Minoan Crete, which was influenced by Egyptian culture. Faience material, for instance, has recovered from the Knossos archaeological site. The Moors brought the technique of tin-glazed earthenware to Al-Andalus, where the art of lustreware with metallic glazes was perfected, from Málaga in Andalusia and later Valencia these Hispano-Moresque wares were exported, either directly or via the Balearic Islands to Italy and the rest of Europe. This type of Spanish pottery owed much to its Moorish inheritance, in Italy, locally produced tin-glazed earthenwares, initiated in the fourteenth century, reached a peak in the late fifteenth and early sixteenth centuries. The first northerners to imitate the tin-glazed earthenwares being imported from Italy were the Dutch, English Delftware produced in Lambeth, London, and at other centers, from the late sixteenth century, provided apothecaries with jars for wet and dry drugs. Many of the potters in London were Flemish. By about 1600, blue-and-white wares were being produced, labelling the contents within decorative borders, the production was slowly superseded in the second half of the eighteenth century with the introduction of cheap creamware. Dutch potters in northern Germany established German centres of faience, the first manufactories in Germany were opened at Hanau and Heusenstamm, in Switzerland, Zunfthaus zur Meisen near Fraumünster church houses the porcelain and faience collection of the Swiss National Museum in Zurich. Faïence parlante bears mottoes often on decorative labels or banners, wares for apothecaries, including albarello, can bear the names of their intended contents, generally in Latin and often so abbreviated to be unrecognizable to the untutored eye. Mottoes of fellowships and associations became popular in the 18th century, at the low end of the market, local manufactories continued to supply regional markets with coarse and simple wares. These so-called majolica wares were also made by Wedgwood and numerous smaller Staffordshire potteries round Burslem
22.
Maiolica
–
Maiolica, also called Majolica is Italian tin-glazed pottery dating from the Renaissance period. It is decorated in colours on a background, sometimes depicting historical and mythical scenes. By the late 15th century, several places, mainly small cities in northern and central Italy, were producing sophisticated pieces for a market in Italy. The name is thought to come from the medieval Italian word for Majorca, moorish potters from Majorca are reputed to have worked in Sicily and it has been suggested that their wares reached the Italian mainland from Caltagirone. An alternative explanation of the name is that it comes from the Spanish term obra de Malaga, denoting “ wares from Malaga”. or obra de mélequa, the Spanish name for lustre. In the 15th century, the term maiolica referred solely to lusterware, eventually the term came to be used when describing ceramics made in Italy, lustred or not, of tin-glazed earthenware. With the Spanish conquest of Mexico, tin-glazed maiolica wares came to be produced in the Valley of Mexico as early as 1540, mexican maiolica is known famously as Talavera. By a convenient extension and limitation the name may be applied to all tin-glazed ware, of whatever nationality, the name faïence being reserved for the later wares of the 17th Century onwards, either in original styles or, more frequently, in the Dutch-Chinese tradition. The term maiolica is sometimes applied to modern tin-glazed ware made by studio potters, the word, majolica, is also used for Victorian majolica, a hard-wearing type of pottery where coloured lead glazes are applied direct to the biscuit. Tin glazing creates a brilliant white, opaque surface for painting, the colours are applied as metallic oxides or as fritted underglazes to the unfired glaze, which absorbs pigment like fresco, making errors impossible to fix, but preserving the brilliant colors. Sometimes the surface is covered with a glaze that lends greater shine. In the case of lustred wares, a further firing at a temperature is required. Kilns required wood as well as suitable clay, glaze was made from sand, wine lees, lead compounds and tin compounds. Analysis of samples of Italian maiolica pottery from the Middle Ages has indicated that tin was not always a component of the glaze, such archaic wares are sometimes called proto-maiolica. During the later fourteenth century, the palette of colours was expanded from the traditional manganese purple and copper green to include cobalt blue, antimony yellow. Sgraffito wares were produced, in which the white tin-oxide glaze was scratched through to produce a design from the revealed body of the ware. Refined production of tin-glazed earthenwares made for more local needs was concentrated in central Italy from the later thirteenth century. The medium was adopted by the Della Robbia family of Florentine sculptors
23.
Delftware
–
Delftware or Delft pottery, also known as Delft Blue, is blue and white pottery made in and around Delft in the Netherlands and the tin-glazed pottery made in the Netherlands from the 16th century. Delftware in the sense is one of the types of tin-glazed earthenware or faience in which a white glaze is applied. It also forms part of the family of blue and white pottery, using variations of the plant-based decoration first developed in 14th century Chinese porcelain. Delftware includes pottery objects of all such as plates, ornaments. The most highly-regarded period of production is about 1640–1740, the earliest tin-glazed pottery in the Netherlands was made in Antwerp where the Italian potter Guido da Savino settled in 1500. The manufacture of painted pottery spread from Antwerp to the northern Netherlands, production developed in Middelburg and Haarlem in the 1570s and in Amsterdam in the 1580s. Much of the work was produced in Delft, but simple everyday tin-glazed pottery was made in places such as Gouda, Rotterdam, Amsterdam. The main period of pottery in the Netherlands was 1640–1740. From about 1640 Delft potters began using personal monograms and distinctive factory marks. The Guild of St Luke, to which painters in all media had to belong, the Double Tankard, The Young Moors Head, and The Three Bells. The use of marl, a type of rich in calcium compounds, allowed the Dutch potters to refine their technique. The usual clay body of Delftware was a blend of three clays, one local, one from Tournai and one from the Rhineland. From about 1615, the potters began to coat their pots completely in white tin glaze instead of covering only the painting surface and coating the rest with clear ceramic glaze. They then began to cover the tin-glaze with clear glaze, which gave depth to the surface and smoothness to cobalt blues. During the Dutch Golden Age, the Dutch East India Company had a trade with the East. The Chinese workmanship and attention to detail impressed many, only the richest could afford the early imports. Dutch potters did not immediately imitate Chinese porcelain, they began to do so after the death of the Wanli Emperor in 1620, potters now saw an opportunity to produce a cheap alternative for Chinese porcelain. After much experimenting they managed to make a type of earthenware which was covered with a white tin glaze
24.
Salt glaze pottery
–
Sodium from the salt reacts with silica in the clay body to form a glassy coating of sodium silicate. The glaze may be colourless or may be coloured various shades of brown, blue, the earliest known production of salt glazed stoneware was in the Rhineland of Germany around 1400. Initially, the process was used on earthenware, by the 15th century, small pottery towns of the Westerwald, including Höhr-Grenzhausen, Siegberg, Köln, and Raeren in Flanders, were producing a salt-glazed stoneware. In the 17th century, salt glaze gained popularity in England as well as in Colonial America, Westerwald Pottery was characterized by stamped medallions and the use of a cobalt oxide based colorant for decoration. Production of salt glaze pottery in Westerwald ceased because of environmental considerations in 1983, in the UK during the 17th century and 18th century high quality salt-glazed stoneware was produced in Derbyshire, Nottinghamshire, London and Staffordshire. Salt glazed pottery was popular in North America from the early 17th century until the early 19th century. Whilst its manufacturer in America increased from the earliest dated production, the earliest known production of salt glaze pottery in Australia has been dated to 1850-1883. During the 20th century the technique was promoted for studio pottery use by Bernard Leach, in the 1950s it was introduced into Japanese craft pottery through Leachs association with Shoji Hamada. Don Reitz introduced salt glazing into the curriculum at Alfred University, New York in 1959, due to the significant amount of air pollution resulting from the process environmental clean air restrictions led to the demise of widespread use of salt glazing. Experiments in stoneware production began in England during the part of the 17th century. The earliest evidence has been dated 1650–1700 at the site of a kiln at Woolwich Ferry, the similarity of the ware to German products of a similar era has led it to be attributed to immigrant potters. A significant English manufacturer of salt glaze pottery was John Dwight at the Fulham Pottery, the company was founded in 1815 when John Doulton formed a partnership with the owner, Martha Jones and foreman, John Watts, of an existing pottery in Lambeth. Initially the factory specialised in utilitarian salt glazed stoneware, similar to that produced by the Fulham factories, during the 1830s and 1840s considerable amounts of salt-glazed sewer-pipes were produced by Doultons following Sir Edwin Chadwicks advocacy of improved sanitary conditions. Doultons were also one of the earliest manufacturers of electrical insulators, initially using salt glaze stoneware, also, from about 1830 they started production of salt glaze stoneware vessels, which were valued for their acid resistance, for the emerging chemical industries. From the 1850s Doulton & Co and their salt glaze decorative products became known as Doulton Ware. By 1890 their decorative stoneware were so successful that 350 designers and artists were employed at the Lambeth factory, doulton’s Lambeth factory closed in 1956, due largely to new clean air regulations that prohibited the production of salt glaze in the urban environment. Production, but not of salt glazing, was transferred to their factory in Burslem which had established in 1877. Several other stoneware potteries also operated in Lambeth between the mid-18th & 19th centuries, including James Stiff and Sons and Stephen Greens Imperial pottery, the former having started his pottery career at Doulton in 1830, before opening his own factory in 1843
25.
Potash
–
Potash /ˈpɒtæʃ/ is any of various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, which refers to plant ashes soaked in water in a pot, the word potassium is derived from potash. Potash is produced worldwide at amounts exceeding 30 million tonnes per year, various types of fertilizer-potash thus constitute the single largest global industrial use of the element potassium. Potassium was first derived by electrolysis of caustic potash, in 1807, Potash refers to potassium compounds and potassium-bearing materials, the most common being potassium chloride. The term potash comes from the Middle Dutch word potaschen, approximately 10% by weight of common wood ash can be recovered as pot ash. Later, potash became the term applied to naturally occurring potassium salts. Potash ores are rich in potassium chloride and sodium chloride and are typically obtained by conventional shaft mining with the extracted ore ground into a powder. Other methods include dissolution mining and evaporation methods from brines, in the evaporation method hot water is injected into the potash which is dissolved and then pumped to the surface where it is concentrated by solar induced evaporation. Amine reagents are added to either the mined or evaporated solutions. The amine coats the KCl but not NaCl, air bubbles cling to the amine + KCl and float it to the surface while the NaCl and clay sink to the bottom. The surface is skimmed for the amine + KCl which is dried and packaged for use as a K rich fertilizer—KCl dissolves readily in water and is available quickly for plant nutrition. Potash deposits can be all over the world. At present deposits are being mined in Canada, Russia, China, Belarus, Israel, Germany, Chile, the United States, Jordan, Spain, Potash has been used in bleaching textiles, making glass, and making soap, since about AD500. Potash was principally obtained by leaching the ashes of land and sea plants, beginning in the 14th century potash was mined in Ethiopia. One of the worlds largest deposits,140 to 150 million tons, is located in the Tigrays Dallol area, Potash was one of the most important industrial chemicals in Canada. It was refined from the ashes of broadleaved trees and produced primarily in the areas of Europe, Russia. The first U. S. patent of any kind was issued in 1790 to Samuel Hopkins for an improvement in the making of Pot ash and Pearl ash by a new Apparatus, Pearl ash was a purer quality made by the ignition of cream of tartar. Potash pits were used in England to produce potash that was used in making soap for the preparation of wool for yarn production
26.
Lime (material)
–
Lime is a calcium-containing inorganic material in which carbonates, oxides, and hydroxides predominate. In the strict sense of the term, lime is calcium oxide or calcium hydroxide and it is also the name of the natural mineral CaO which occurs as a product of coal seam fires and in altered limestone xenoliths in volcanic ejecta. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering and these materials are still used in large quantities as building and engineering materials, as chemical feedstocks, and for sugar refining, among other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World, Lime is used extensively for wastewater treatment with ferrous sulfate. The rocks and minerals from which these materials are derived, typically limestone or chalk, are composed primarily of calcium carbonate and they may be cut, crushed or pulverized and chemically altered. Lime kilns are the used for lime burning and slaking. When the term is encountered in a context, it usually refers to agricultural lime. Otherwise it most commonly means slaked lime, as the dangerous form is usually described more specifically as quicklime or burnt lime. In the lime industry, limestone is a term for rocks that contain 80% or more of calcium or magnesium carbonates, including marble, chalk, oolite. Further classification is by composition as high calcium, argillaceous, silicious, conglomerate, magnesian, dolomite, uncommon sources of lime include coral, sea shells, calcite, and ankerite. Limestone is extracted from quarries or mines, dry slaking is when quicklime is slaked with just enough water to hydrate the quicklime, but remain as a powder and is referred to as hydrated lime. In wet slaking, enough water, but not too much, is added to hydrate the quicklime to a referred to as lime putty. Because lime has a property with bricks and stones, it is often used as binding material in masonry works. It is also used in whitewashing as wall coat to adhere the whitewash onto the wall, the process by which limestone is converted to quicklime by heating, then to slaked lime by hydration, and naturally reverts to calcium carbonate by carbonation is called the lime cycle. The conditions and compounds present during each step of the cycle have a strong influence of the end product, thus the complex. An example is when slaked lime is mixed into a slurry with sand. When the masonry has been laid, the lime in the mortar slowly begins to react with carbon dioxide to form calcium carbonate according to the reaction. The carbon dioxide that takes part in reaction is principally available in the air or dissolved in rainwater so pure lime mortar will not recarbonate under water or inside a thick masonry wall
27.
Feldspath
–
Feldspars are a group of rock-forming tectosilicate minerals that make up about 40% of the Earths continental crust. Feldspars crystallize from magma as veins in both intrusive and extrusive rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of plagioclase feldspar is known as anorthosite. Feldspars are also found in types of sedimentary rocks. The name feldspar derives from the German Feldspat, a compound of the words Feld, field, and Spat, the change from Spat to -spar was influenced by the English word spar, a synonym for mineral. Feldspathic refers to materials that contain feldspar, the alternate spelling, felspar, has largely fallen out of use. This group of minerals consists of tectosilicates, solid solutions between albite and anorthite are called plagioclase, or more properly plagioclase feldspar. Only limited solid solution occurs between K-feldspar and anorthite, and in the two solid solutions, immiscibility occurs at temperatures common in the crust of the earth. Albite is considered both a plagioclase and alkali feldspar, the alkali feldspars are as follows, orthoclase —KAlSi3O8 sanidine —AlSi3O8 microcline —KAlSi3O8 anorthoclase —AlSi3O8 Sanidine is stable at the highest temperatures, and microcline at the lowest. Perthite is a texture in alkali feldspar, due to exsolution of contrasting alkali feldspar compositions during cooling of an intermediate composition. The perthitic textures in the alkali feldspars of many granites can be seen with the naked eye, microperthitic textures in crystals are visible using a light microscope, whereas cryptoperthitic textures can be seen only with an electron microscope. Barium feldspars are also considered alkali feldspars, barium feldspars form as the result of the substitution of barium for potassium in the mineral structure. The barium feldspars are monoclinic and include the following, celsian—BaAl2Si2O8 hyalophane—4O8 The plagioclase feldspars are triclinic, the immiscibility gaps in the plagioclase solid solutions are complex compared to the gap in the alkali feldspars. The play of colours visible in some feldspar of labradorite composition is due to very fine-grained exsolution lamellae, chemical weathering of feldspars results in the formation of clay minerals. About 20 million tonnes of feldspar were produced in 2010, mostly by three countries, Italy, Turkey, and China, Feldspar is a common raw material used in glassmaking, ceramics, and to some extent as a filler and extender in paint, plastics, and rubber. In glassmaking, alumina from feldspar improves product hardness, durability, in ceramics, the alkalis in feldspar act as a flux, lowering the melting temperature of a mixture. Fluxes melt at a stage in the firing process, forming a glassy matrix that bonds the other components of the system together. In the US, about 66% of feldspar is consumed in glassmaking, including glass containers, ceramics and other uses, such as fillers, accounted for the remainder
28.
Materials science
–
The interdisciplinary field of materials science, also commonly termed materials science and engineering, involves the discovery and design of new materials, with an emphasis on solids. Materials science still incorporates elements of physics, chemistry, and engineering, as such, the field was long considered by academic institutions as a sub-field of these related fields. Materials science is a syncretic discipline hybridizing metallurgy, ceramics, solid-state physics and it is the first example of a new academic discipline emerging by fusion rather than fission. Many of the most pressing scientific problems humans currently face are due to the limits of the materials that are available, thus, breakthroughs in materials science are likely to affect the future of technology significantly. Materials scientists emphasize understanding how the history of a material influences its structure, the understanding of processing-structure-properties relationships is called the § materials paradigm. This paradigm is used to advance understanding in a variety of areas, including nanotechnology, biomaterials. Such investigations are key to understanding, for example, the causes of various accidents and incidents. The material of choice of a given era is often a defining point, phrases such as Stone Age, Bronze Age, Iron Age, and Steel Age are great examples. Originally deriving from the manufacture of ceramics and its putative derivative metallurgy, materials science is one of the oldest forms of engineering, modern materials science evolved directly from metallurgy, which itself evolved from mining and ceramics and the use of fire. Materials science has driven, and been driven by, the development of technologies such as rubbers, plastics, semiconductors. Before the 1960s, many materials science departments were named metallurgy departments, reflecting the 19th, a material is defined as a substance that is intended to be used for certain applications. There are a myriad of materials around us—they can be found in anything from buildings to spacecraft, Materials can generally be divided into two classes, crystalline and non-crystalline. The traditional examples of materials are metals, semiconductors, ceramics, New and advanced materials that are being developed include nanomaterials and biomaterials, etc. The basis of science involves studying the structure of materials. Once a materials scientist knows about this structure-property correlation, they can go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and these characteristics, taken together and related through the laws of thermodynamics and kinetics, govern a materials microstructure, and thus its properties. As mentioned above, structure is one of the most important components of the field of materials science, Materials science examines the structure of materials from the atomic scale, all the way up to the macro scale. Characterization is the way materials scientists examine the structure of a material, structure is studied at various levels, as detailed below
29.
Boron trioxide
–
Boron trioxide is one of the oxides of boron. It is a white, glassy solid with the formula B2O3 and it is almost always found as the vitreous form, however, it can be crystallized after extensive annealing. Glassy boron oxide is thought to be composed of rings which are six-membered rings composed of alternating 3-coordinate boron. The crystalline form is composed of BO3 triangles. This trigonal, quartz-like network undergoes a transformation to monoclinic β-B2O3 at several gigapascals. Boron trioxide is produced by treating borax with sulfuric acid in a fusion furnace, at temperatures above 750 °C, the molten boron oxide layer separates out from sodium sulfate. It is then decanted, cooled and obtained in 96–97% purity, another method is heating boric acid above ~300 °C. Boric acid will initially decompose into water steam and metaboric acid at around 170 °C, the reactions are, H3BO3 → HBO2 + H2O2 HBO2 → B2O3 + H2O Boric acid goes to anhydrous microcrystalline B2O3 in a heated fluidized bed. Carefully controlled heating rate avoids gumming as water evolves, internally graphitized tubes via acetylene thermal decomposition are passivated. Crystallization of molten α-B2O3 at ambient pressure is strongly kinetically disfavored, threshold conditions for crystallization of the amorphous solid are 10 kbar and ~200 °C. Its proposed crystal structure in space groups P31, P32 has been revised to enantiomorphic space groups P3121, P3221. Material Safety Data Sheet CDC - NIOSH Pocket Guide to Chemical Hazards - Boron oxide
30.
Sodium
–
Sodium is a chemical element with symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal, Sodium is an alkali metal, being in group 1 of the periodic table, because it has a single electron in its outer shell that it readily donates, creating a positively charged atom—the Na+ cation. Its only stable isotope is 23Na, the free metal does not occur in nature, but must be prepared from compounds. Sodium is the sixth most abundant element in the Earths crust, Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful compounds, sodium hydroxide is used in soap manufacture, and sodium chloride is a de-icing agent. Sodium is an element for all animals and some plants. Sodium ions are the major cation in the fluid and as such are the major contributor to the ECF osmotic pressure. Loss of water from the ECF compartment increases the sodium concentration, isotonic loss of water and sodium from the ECF compartment decreases the size of that compartment in a condition called ECF hypovolemia. In nerve cells, the charge across the cell membrane enables transmission of the nerve impulse—an action potential—when the charge is dissipated. The melting and boiling points of sodium are lower than those of lithium but higher than those of the alkali metals potassium, rubidium. All of these high-pressure allotropes are insulators and electrides.3 nm, spin-orbit interactions involving the electron in the 3p orbital split the D line into two, at 589.0 and 589.6 nm, hyperfine structures involving both orbitals cause many more lines. Twenty isotopes of sodium are known, but only 23Na is stable, 23Na is created in the carbon-burning process in stars by fusing two carbon atoms together, this requires temperatures above 600 megakelvins and a star of at least three solar masses. Two nuclear isomers have been discovered, the one being 24mNa with a half-life of around 20.2 milliseconds. Sodium atoms have 11 electrons, one more than the stable configuration of the noble gas neon. This process requires so little energy that sodium is oxidized by giving up its 11th electron. In contrast, the ionization energy is very high, because the 10th electron is closer to the nucleus than the 11th electron. As a result, sodium usually forms ionic compounds involving the Na+ cation, the most common oxidation state for sodium is +1. It is generally less reactive than potassium and more reactive than lithium, Sodium metal is highly reducing, with the reduction of sodium ions requiring −2.71 volts, though potassium and lithium have even more negative potentials
31.
Potassium
–
Potassium is a chemical element with symbol K and atomic number 19. It was first isolated from potash, the ashes of plants, in the periodic table, potassium is one of the alkali metals. Potassium in nature only in ionic salts. It is found dissolved in sea water, and is part of many minerals, naturally occurring potassium is composed of three isotopes, of which 40K is radioactive. Traces of 40K are found in all potassium, and it is the most common radioisotope in the human body, Potassium is chemically very similar to sodium, the previous element in Group 1 of the periodic table. They have a similar energy, which allows for each atom to give up its sole outer electron. That they are different elements combine with the same anions to make similar salts was suspected in 1702. Most industrial applications of potassium exploit the high solubility in water of potassium compounds, heavy crop production rapidly depletes the soil of potassium, and this can be remedied with agricultural fertilizers containing potassium, accounting for 95% of global potassium chemical production. Potassium ions are necessary for the function of all living cells, fresh fruits and vegetables are good dietary sources of potassium. Potassium is the second least dense metal after lithium and it is a soft solid with a low melting point, and can be easily cut with a knife. Freshly cut potassium is silvery in appearance, but it begins to tarnish toward gray immediately on exposure to air, in a flame test, potassium and its compounds emit a lilac color with a peak emission wavelength of 766.5 nanometers. Neutral potassium atoms have 19 electrons, one more than the stable configuration of the noble gas argon. This process requires so little energy that potassium is readily oxidized by atmospheric oxygen, in contrast, the second ionization energy is very high, because removal of two electrons breaks the stable noble gas electronic configuration. Potassium therefore does not readily form compounds with the state of +2 or higher. Potassium is an active metal that reacts violently with oxygen in water. With oxygen it forms potassium peroxide, and with water potassium forms potassium hydroxide, the reaction of potassium with water is dangerous because of its violent exothermic character and the production of hydrogen gas. Hydrogen reacts again with atmospheric oxygen, producing water, which reacts with the remaining potassium and this reaction requires only traces of water, because of this, potassium and the liquid sodium-potassium — NaK — are potent desiccants that can be used to dry solvents prior to distillation. Because of the sensitivity of potassium to water and air, reactions with other elements are only in an inert atmosphere such as argon gas using air-free techniques
32.
Calcium
–
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft grayish-yellow alkaline earth metal, fifth-most-abundant element by mass in the Earths crust, the ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate. Free calcium metal is too reactive to occur in nature, Calcium is produced in supernova nucleosynthesis. Calcium is a trace element in living organisms. It is the most abundant metal by mass in animals, and it is an important constituent of bone, teeth. In cell biology, the movement of the calcium ion into, Calcium carbonate and calcium citrate are often taken as dietary supplements. Calcium is on the World Health Organizations List of Essential Medicines, Calcium has a wide variety of applications, almost all of which are associated with calcium compounds and salts. Calcium metal is used as a deoxidizer, desulfurizer, and decarbonizer for production of ferrous and nonferrous alloys. In steelmaking and production of iron, Ca reacts with oxygen, Calcium carbonate is used in manufacturing cement and mortar, lime, limestone and aids in production in the glass industry. It also has chemical and optical uses as mineral specimens in toothpastes, Calcium hydroxide solution is used to detect the presence of carbon dioxide in a gas sample bubbled through a solution. The solution turns cloudy where CO2 is present, Calcium arsenate is used in insecticides. Calcium carbide is used to make acetylene gas and various plastics, Calcium chloride is used in ice removal and dust control on dirt roads, as a conditioner for concrete, as an additive in canned tomatoes, and to provide body for automobile tires. Calcium citrate is used as a food preservative, Calcium cyclamate is used as a sweetening agent in several countries. In the United States, it has been outlawed as a suspected carcinogen, Calcium gluconate is used as a food additive and in vitamin pills. Calcium hypochlorite is used as a swimming pool disinfectant, as an agent, as an ingredient in deodorant. Calcium permanganate is used in rocket propellant, textile production, as a water sterilizing agent. Calcium phosphate is used as a supplement for animal feed, fertilizer, in production for dough and yeast products, in the manufacture of glass. Calcium phosphide is used in fireworks, rodenticide, torpedoes, Calcium sulfate is used as common blackboard chalk, as well as, in its hemihydrate form, Plaster of Paris
33.
Aluminium oxide
–
Aluminium oxide or aluminum oxide is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. It is the most commonly occurring of several aluminium oxides, and it is commonly called alumina, and may also be called aloxide, aloxite, or alundum depending on particular forms or applications. It occurs naturally in its crystalline polymorphic phase α-Al2O3 as the mineral corundum, varieties of form the precious gemstones ruby. Al2O3 is significant in its use to produce metal, as an abrasive owing to its hardness. Corundum is the most common naturally occurring form of aluminium oxide. Rubies and sapphires are gem-quality forms of corundum, which owe their characteristic colors to trace impurities, rubies are given their characteristic deep red color and their laser qualities by traces of chromium. Sapphires come in different colors given by various other impurities, such as iron, Al2O3 is an electrical insulator but has a relatively high thermal conductivity for a ceramic material. Aluminium oxide is insoluble in water, in its most commonly occurring crystalline form, called corundum or α-aluminium oxide, its hardness makes it suitable for use as an abrasive and as a component in cutting tools. Aluminium oxide is responsible for the resistance of aluminium to weathering. Metallic aluminium is very reactive with oxygen, and a thin passivation layer of aluminium oxide forms on any exposed aluminium surface. This layer protects the metal from further oxidation, the thickness and properties of this oxide layer can be enhanced using a process called anodising. A number of alloys, such as bronzes, exploit this property by including a proportion of aluminium in the alloy to enhance corrosion resistance. Aluminium oxide was taken off the United States Environmental Protection Agencys chemicals lists in 1988, aluminium oxide is on EPAs Toxics Release Inventory list if it is a fibrous form. Al2O3 +6 HF →2 AlF3 +3 H2O Al2O3 +2 NaOH +3 H2O →2 NaAl4 The most common form of aluminium oxide is known as corundum. The oxygen ions form a hexagonal close-packed structure with aluminium ions filling two-thirds of the octahedral interstices. In terms of its crystallography, corundum adopts a trigonal Bravais lattice with a group of R-3c. The primitive cell contains two units of aluminium oxide. Each has a crystal structure and properties
34.
Clay
–
Clay is a fine-grained natural rock or soil material that combines one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Clays are plastic due to water content and become hard, brittle. Depending on the content in which it is found, clay can appear in various colours from white to dull grey or brown to deep orange-red. Although many naturally occurring deposits include both silts and clay, clays are distinguished from other fine-grained soils by differences in size, silts, which are fine-grained soils that do not include clay minerals, tend to have larger particle sizes than clays. There is, however, some overlap in size and other physical properties. The distinction between silt and clay varies by discipline, geologists and soil scientists usually consider the separation to occur at a particle size of 2 µm, sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils Atterberg limits, ISO14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. These solvents, usually acidic, migrate through the rock after leaching through upper weathered layers. In addition to the process, some clay minerals are formed through hydrothermal activity. There are two types of deposits, primary and secondary. Primary clays form as residual deposits in soil and remain at the site of formation, secondary clays are clays that have been transported from their original location by water erosion and deposited in a new sedimentary deposit. Clay deposits are associated with very low energy depositional environments such as large lakes. Depending on the source, there are three or four main groups of clays, kaolinite, montmorillonite-smectite, illite, and chlorite. Chlorites are not always considered to be a clay, sometimes being classified as a group within the phyllosilicates. There are approximately 30 different types of clays in these categories. Varve is clay with visible annual layers, which are formed by deposition of those layers and are marked by differences in erosion. This type of deposit is common in glacial lakes
35.
Iron oxide
–
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides, common rust is a form of iron oxide. Iron oxides are used as inexpensive, durable pigments in paints, coatings. Colors commonly available are in the end of the yellow/orange/red/brown/black range. When used as a coloring, it has E number E172. Limonite Iron oxide nanoparticles List of inorganic pigments Information from Nano-Oxides, http, //chemed. chem. purdue. edu/demos/demosheets/12.3. html http, //minerals. usgs. gov/minerals/pubs/commodity/iron_oxide/ CDC - NIOSH Pocket Guide to Chemical Hazards de
36.
Basic copper carbonate
–
Basic copper carbonate is a chemical compound, more properly called copper carbonate hydroxide. It is a compound consisting of the ions copper Cu2+, carbonate CO2−3. The name most commonly refers to the compound with formula Cu 2CO32 and it is a green crystalline solid that occurs in nature as the mineral malachite. It has been used since antiquity as a pigment, and it is used as such in artist paints, sometimes called vertiter, green bice. Sometimes the name is used for Cu 322, a crystalline solid also known as the mineral azurite. It too has used as pigment, sometimes under the name mountain blue or blue verditer. Both malachite and azurite can be found in the verdigris patina that is found on weathered brass, bronze, and copper. The composition of the patina can vary, in an environment depending on the environment a basic chloride may be present. This compound is often improperly called copper carbonate, cupric carbonate, the true copper carbonate CuCO3 is not known to occur naturally. It is decomposed by water or moisture from the air, and was synthesized only in 1973 by high temperature, basic copper carbonate is prepared by combining aqueous solutions of copper sulfate and sodium carbonate at ambient temperature and pressure. Copper carbonate was the first compound to be broken down into several and it was broken down in 1794 by the French chemist Joseph Louis Proust. When heated, it decomposes to form CO2 and CuO, cupric oxide. The basic copper carbonates, malachite and azurite, both decompose forming CO2 and CuO, cupric oxide, both malachite and azurite basic copper carbonates have been used as pigments. One example of the use of azurite and its artificial form blue verditer is the portrait of the family of Balthasar Gerbier by Peter Paul Rubens. The green skirt of Deborah Kip is painted in azurite, smalt, blue verditer, yellow ochre, the green color is obviously achieved by mixing blue and yellow pigments. It has also used in some types of make-up, like lipstick. It also has used for many years as an effective algaecide in farm ponds. National Pollutant Inventory – copper and compounds fact sheet Azurite at ColourLex Blue verditer at ColourLex
37.
Cobalt(II) carbonate
–
Cobalt carbonate is the inorganic compound with the formula CoCO3. This reddish paramagnetic solid is an intermediate in the purification of cobalt from its ores. It is a pigment, and a precursor to catalysts. Commercially available pale violet basic cobalt carbonate, with the formula CoCO3(Coxy and it is prepared by heating cobaltous sulfate with a solution of sodium bicarbonate. Heating the carbonate, i. e. calcining, proceeds in the way,3 CoCO3 + 1/2 O2 → Co3O4 +3 CO2 The resulting Co3O4 converts reversibly to CoO at high temperatures. It is a component of dietary supplements since cobalt is an essential element and it is a precursor to blue pottery glazes, famously in the case of Delftware. The compound is harmful if swallowed, and irritating to eyes and skin
38.
Zirconium dioxide
–
Zirconium dioxide, sometimes known as zirconia, is a white crystalline oxide of zirconium. Its most naturally occurring form, with a crystalline structure, is the mineral baddeleyite. A dopant stabilized cubic structured zirconia, cubic zirconia, is synthesized in various colours for use as a gemstone, Zirconia is produced by calcining zirconium compounds, exploiting its high thermal stability. Three phases are known, monoclinic <1,170 °C, tetragonal 1, 170–2,370 °C, the trend is for higher symmetry at higher temperatures, as is usually the case. A few percentage of the oxides of calcium or yttrium stabilize the cubic phase, the very rare mineral tazheranite O2 is cubic. Unlike TiO2, which features six-coordinate Ti in all phases, monoclinic zirconia consists of seven-coordinate zirconium centres and this difference is attributed to the larger size of Zr atom relative to the Ti atom. It is slowly attacked by concentrated hydrofluoric acid and sulfuric acid, when heated with carbon, it converts to zirconium carbide. When heated with carbon in the presence of chlorine, it converts to zirconium tetrachloride and this conversion is the basis for the purification of zirconium metal and is analogous to the Kroll process. Zirconium dioxide is one of the most studied ceramic materials, ZrO2 adopts a monoclinic crystal structure at room temperature and transitions to tetragonal and cubic at higher temperatures. The change of volume caused by the structure transitions from to tetragonal to monoclinic to cubic induces large stresses, when the zirconia is blended with some other oxides, the tetragonal and/or cubic phases are stabilized. Effective dopants include magnesium oxide, yttrium oxide, calcium oxide, Zirconia is often more useful in its phase stabilized state. Upon heating, zirconia undergoes disruptive phase changes, by adding small percentages of yttria, these phase changes are eliminated, and the resulting material has superior thermal, mechanical, and electrical properties. In some cases, the phase can be metastable. This phase transformation can then put the crack into compression, retarding its growth and this mechanism is known as transformation toughening, and significantly extends the reliability and lifetime of products made with stabilized zirconia. The ZrO2 band gap is dependent on the phase and preparation methods, a special case of zirconia is that of tetragonal zirconia polycrystal, or TZP, which is indicative of polycrystalline zirconia composed of only the metastable tetragonal phase. Stabilized zirconia is used in sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. This high ionic conductivity makes it one of the most useful electroceramics, zirconium dioxide is also used as the solid electrolyte in electrochromic devices. Zirconia is a precursor to the electroceramic lead zirconate titanate, which is a high-K dielectric, which is found in myriad components
39.
Iznik pottery
–
The designs combined traditional Ottoman arabesque patterns with Chinese elements. The change was almost certainly a result of intervention and patronage by the recently established Ottoman court in Istanbul who greatly valued Chinese blue-and-white porcelain. During the 16th century the decoration of the pottery gradually changed in style, becoming looser, initially turquoise was combined with the dark shade of cobalt blue and then the pastel shades of sage green and pale purple were added. Finally, in the middle of the century, a very characteristic bole red replaced the purple, the ceramic collection of the Topkapi Palace includes over ten thousand pieces of Chinese porcelain but almost no Iznik pottery. Following the establishment of the Ottoman Empire in the early 14th century, after this initial period, Iznik vessels were made in imitation of Chinese porcelain, which was highly prized by the Ottoman sultans. As the potters were unable to make porcelain, the vessels produced were fritware, the originality of the potters was such that their use of Chinese originals has been described as adaptation rather than imitation. Chinese ceramics had long admired, collected and emulated in the Islamic world. This was especially so in the Ottoman court and the Safavid court in Persia which had important collections of Chinese blue-and-white porcelain, such Chinese porcelains influenced the style of Safavid pottery and had a strong impact on the development of Iznik ware. By the mid-16th century, Iznik had its own vocabulary of floral, decoration progressed from pure symmetry to subtle rhythms. Although it is now believed that all the pottery was produced in Iznik the earlier names associated with the different styles are often used. In the 19th century until the 1860s all Islamic pottery was known as Persian ware. However, between 1865 and 1872 the Musée de Cluny in Paris acquired a collection of polychrome pottery with a design that included a bright sealing-wax red. The ewer has an inscription in Armenian script under the glaze on its base stating that the vessel was in commemoration of Abraham, servant of God, as a result, pottery with similar spiral patterns became known as Golden Horn ware. It was not until the 1930s that art historians realised that the different styles of pottery were probably all produced in Iznik. This chronology has been generally accepted, the Abraham of Kutahia ewer of 1510 is not the only vessel with a possible Kütahya origin. Lane argued that it was unlikely that either the Abraham of Kutahia ewer or the bottle had been made in Kütahya. The designs, materials and manufacturing technique appear to have similar to that used in İznik. Kütahya is further from Istanbul with less access to the capital and was probably only a small pottery producing centre in the 16th century
40.
Enderun School
–
Over the centuries, the Enderun School was fairly successful in creating Ottoman statesmen by drawing among the empires various ethnic groups and giving them a common Muslim education. The school was run by the Inner Service of the Ottoman palace and had both academic and military purposes, the graduates were expected to devote themselves to government service and be free of links to lower social groups. The Enderun Schools gifted education program has called the worlds first institutionalized education for the gifted. The growth of Ottoman Empire is attributed and was dependent on the selection and education of statesmen, a vital component of Mehmet IIs goal to revive the Roman Empire was to establish a special school to select the best youngsters within the Empire and to mold them for government. Mehmet II improved the palace school founded by his father, Murat II. There were seven halls or grades within the Palace School, and within each there were 12 teachers responsible for the students mental. Students wore special uniforms designated by their achievement level, and Miller indicated that additional buildings included the library, mosque, music conservatories, dormitories, the Enderun system consisted of three preparatory schools located outside of the palace in addition to the one within the palace walls itself. According to Miller, there were 1, 000-2,000 students in three Enderun Colleges, and about 300 students in the top school in the Palace, the graduation ceremony for students leaving the Enderun School was known as çıkma. The graduates themselves were referred as çıkma, the name çıkma literary means leaving or pulling out. The pages were leaving Palace School and palace service to continue their training in the functional service and this transferral occurred every two to seven years, or after the accession of new sultan to the throne. The successful graduates were assigned according to their abilities into two positions, governmental or science, and those who failed to advance were assigned to military. One of the most distinctive properties of the school was its merit system consisting of carefully graded rewards and corresponding punishments
41.
Istanbul
–
Istanbul, historically known as Constantinople and Byzantium, is the most populous city in Turkey and the countrys economic, cultural, and historic center. Istanbul is a city in Eurasia, straddling the Bosphorus strait between the Sea of Marmara and the Black Sea. Its commercial and historical center lies on the European side and about a third of its population lives on the Asian side, the city is the administrative center of the Istanbul Metropolitan Municipality, both hosting a population of around 14.7 million residents. Istanbul is one of the worlds most populous cities and ranks as the worlds 7th-largest city proper, founded under the name of Byzantion on the Sarayburnu promontory around 660 BCE, the city developed to become one of the most significant in history. After its reestablishment as Constantinople in 330 CE, it served as a capital for almost 16 centuries, during the Roman and Byzantine, the Latin. Overlooked for the new capital Ankara during the period, the city has since regained much of its prominence. The population of the city has increased tenfold since the 1950s, as migrants from across Anatolia have moved in, arts, music, film, and cultural festivals were established at the end of the 20th century and continue to be hosted by the city today. Infrastructure improvements have produced a complex transportation network, considered a global city, Istanbul has one of the fastest-growing metropolitan economies in the world. It hosts the headquarters of many Turkish companies and media outlets and accounts for more than a quarter of the gross domestic product. Hoping to capitalize on its revitalization and rapid expansion, Istanbul has bid for the Summer Olympics five times in twenty years, the first known name of the city is Byzantium, the name given to it at its foundation by Megarean colonists around 660 BCE. The name is thought to be derived from a personal name, ancient Greek tradition refers to a legendary king of that name as the leader of the Greek colonists. Modern scholars have hypothesized that the name of Byzas was of local Thracian or Illyrian origin. He also attempted to promote the name Nova Roma and its Greek version Νέα Ῥώμη Nea Romē, the use of Constantinople to refer to the city during the Ottoman period is now considered politically incorrect, even if not historically inaccurate, by Turks. By the 19th century, the city had acquired other names used by foreigners or Turks. Europeans used Constantinople to refer to the whole of the city, pera was used to describe the area between the Golden Horn and the Bosphorus, but Turks also used the name Beyoğlu. The name İstanbul is commonly held to derive from the Medieval Greek phrase εἰς τὴν Πόλιν and this reflected its status as the only major city in the vicinity. The importance of Constantinople in the Ottoman world was reflected by its Ottoman name Der Saadet meaning the gate to Prosperity in Ottoman. An alternative view is that the name evolved directly from the name Constantinople, with the first, a Turkish folk etymology traces the name to Islam bol plenty of Islam because the city was called Islambol or Islambul as the capital of the Islamic Ottoman Empire
42.
Mineral
–
A mineral is a naturally occurring chemical compound, usually of crystalline form and abiogenic in origin. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids, the study of minerals is called mineralogy. There are over 5,300 known mineral species, over 5,070 of these have been approved by the International Mineralogical Association, the silicate minerals compose over 90% of the Earths crust. The diversity and abundance of species is controlled by the Earths chemistry. Silicon and oxygen constitute approximately 75% of the Earths crust, which translates directly into the predominance of silicate minerals, minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species, changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Minerals can be described by their various properties, which are related to their chemical structure. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, more specific tests for describing minerals include magnetism, taste or smell, radioactivity and reaction to acid. Minerals are classified by key chemical constituents, the two dominant systems are the Dana classification and the Strunz classification, the silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a unit of a 4− silica tetrahedron—that is, a silicon cation coordinated by four oxygen anions. These tetrahedra can be polymerized to give the subclasses, orthosilicates, disilicates, cyclosilicates, inosilicates, phyllosilicates, other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates. The first criterion means that a mineral has to form by a natural process, stability at room temperature, in the simplest sense, is synonymous to the mineral being solid. More specifically, a compound has to be stable or metastable at 25 °C, modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula, many mineral groups and species are composed of a solid solution, pure substances are not usually found because of contamination or chemical substitution. Finally, the requirement of an ordered atomic arrangement is usually synonymous with crystallinity, however, crystals are also periodic, an ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage. There have been recent proposals to amend the definition to consider biogenic or amorphous substances as minerals. The formal definition of an approved by the IMA in 1995, A mineral is an element or chemical compound that is normally crystalline. However, if geological processes were involved in the genesis of the compound, Mineral classification schemes and their definitions are evolving to match recent advances in mineral science
43.
Oxide
–
An oxide /ˈɒksaɪd/ is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. Oxide itself is the dianion of oxygen, an O2– atom, Metal oxides thus typically contain an anion of oxygen in the oxidation state of −2. Most of the Earths crust consists of oxides, the result of elements being oxidized by the oxygen in air or in water. Hydrocarbon combustion affords the two principal carbon oxides, carbon monoxide and carbon dioxide, even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a skin of Al2O3 that protects the foil from further corrosion. Individual elements can form multiple oxides, each containing different amounts of the element. Certain elements can form many different oxides, such those of nitrogen, due to its electronegativity, oxygen forms stable chemical bonds with almost all elements to give the corresponding oxides. Noble metals are prized because they resist direct chemical combination with oxygen, two independent pathways for corrosion of elements are hydrolysis and oxidation by oxygen. The combination of water and oxygen is even more corrosive, virtually all elements burn in an atmosphere of oxygen, or an oxygen rich environment. In the presence of water and oxygen, some elements— sodium—react rapidly, even dangerously, in part for this reason, alkali and alkaline earth metals are not found in nature in their metallic, i. e. native, form. Caesium is so reactive with oxygen that it is used as a getter in vacuum tubes, the surface of most metals consists of oxides and hydroxides in the presence of air. A well-known example is aluminium foil, which is coated with a film of aluminium oxide that passivates the metal. The aluminium oxide layer can be built to greater thickness by the process of electrolytic anodising, though solid magnesium and aluminium react slowly with oxygen at STP—they, like most metals, burn in air, generating very high temperatures. Finely grained powders of most metals can be explosive in air. Consequently, they are used in Solid-fuel rockets. In dry oxygen, iron forms iron oxide, but the formation of the hydrated ferric oxides, Fe2O3−x2x. Free oxygen production by photosynthetic bacteria some 3.5 billion years ago precipitated iron out of solution in the oceans as Fe2O3 in the important iron ore hematite. Oxides have a range of different structures, from molecules to polymeric
44.
Airbrush
–
An airbrush is a small, air-operated tool that sprays various media, most often paint but also ink and dye, by a process of nebulization. Spray painting developed from the airbrush and is considered to employ a type of airbrush, the first airbrush, depending on the definition, was patented in 1876 by Francis Edgar Stanley of Newton, Massachusetts. Stanley and his brother later invented a process for continuously coating photographic plates but are perhaps best known for their Stanley Steamer. No artistic images that used this paint distributor / atomiser exist or are as yet known, the first instrument to be named the paint distributor was developed by Abner Peeler for the painting of watercolors and other artistic purposes and used a hand-operated compressor. It was rather crude, being based on a number of parts in a jewellers workshop such as old screwdrivers. It took 4 years of development before a working prototype was developed by Liberty Walkup of Mt. Morris, Illinois. Walkup repatented the work under the name of air-brush, a name his wife Mimi Walkup came up with and his wife would later go on to be the founder of the Illinois Art School where airbrushing was taught to students from all over the world. In that same rented 4 story building Rockford Air-Brush would be established under Liberty Walkup, the Walkups taught airbrush technique to American Impressionist master Wilson Irvine at the Air Brush School in Rockford, Illinois. The first certain atomising type airbrush was invented by Charles Burdick in 1893, Burdick founded the Fountain Brush Company in the US, and launched the first series of airbrushes onto the market. This device was essentially the same as an airbrush, resembling a pen. Aerograph, Burdicks original company, still makes and sells airbrushes in England, Thayer and Chandler were acquired by Badger Air-Brush Co. in 2000. Badger Air-Brush continues the Thayer and Chandler tradition of manufacturing quality airbrush guns, tools and compressors out of Franklin Park, for more a detailed academic study, the University of Wales Library holds a detailed PhD on airbrush history. The Franklin Institute in Philadelphia, the Public Library in Rockford Illinois and this was authored by Dr. Andy Penaluna, now Professor of Creative Entrepreneurship at Swansea Metropolitan University. The high velocity of the air atomizes the paint into very tiny droplets as it blows past a very fine paint-metering component, the paint is carried onto paper or other surfaces. The operator controls the amount of paint using a trigger which opens more or less a very fine tapered needle that is the control element of the paint-metering component. An extremely fine degree of atomization is what allows an artist to create such smooth blending effects using the airbrush, the technique allows for the blending of two or more colors in a seamless way, with one color slowly becoming another color. Freehand airbrushed images, without the aid of stencils or friskets, have a floating quality, a skilled airbrush artist can produce paintings of photographic realism or can simulate almost any painting medium. Painting at this level involves supplementary tools, such as masks and friskets
. PMID 23057678.
