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Goldbeating
Goldbeating is the process of hammering gold into an extremely thin unbroken sheet for use in gilding. History 5,000 years ago, Egyptian artisans recognized the extraordinary durability and malleability of gold and became the first goldbeaters and gilders. They pounded gold using a round stone to create the thinnest leaf possible. Except for the introduction of a cast iron hammer and a few other innovations, the tools and techniques have remained virtually unchanged for thousands of years. Process Rolling The karat and color of gold leaf varies depending on the amount of silver or copper added to the gold. Most goldbeaters make 22 karat leaf. The gold and its alloy are put in a crucible and melted in a furnace. The liquid gold is poured into a mold to cast it into a bar. The bar of gold is put through a rolling mill repeatedly. Each time through the mill, the rollers are adjusted closer and closer to each other, to make the gold thinner and thinner. The bar is rolled to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goldbeater's Skin
Goldbeater's skin is the processed outer membrane of the intestine of an animal, typically cattle, which is valued for its strength against tearing. The term derives from its traditional use as durable layers interleaved between sheets of gold stock during the process of making gold leaf by goldbeating, as a batch process producing many "leaves" at the same time. In the early modern production of airships, application of its high strength-to-weight ratio and reliability were crucial for building at least the largest examples. Manufacture To manufacture goldbeater's skin, the gut of oxen (or other cattle) is soaked in a dilute solution of potassium hydroxide, washed, stretched, beaten flat and thin, and treated chemically to prevent putrefaction. A pack of 1,000 pieces of goldbeater's skin requires the gut of about 400 oxen and is thick. Up to 120 sheets of gold laminated with goldbeater's skin can be beaten at the same time, since the skin is thin and elastic and does not te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Leaf
Gold leaf is gold that has been hammered into thin sheets (usually around 0.1 µm thick) by goldbeating and is often used for gilding. Gold leaf is available in a wide variety of karats and shades. The most commonly used gold is 22-karat yellow gold. Gold leaf is a type of metal leaf, but the term is rarely used when referring to gold leaf. The term ''metal leaf'' is normally used for thin sheets of metal of any color that do not contain any real gold. Pure gold is 24 karat. Real, yellow gold leaf is approximately 91.7% pure (i.e. 22-karat) gold. Silver-colored white gold is about 50% pure gold. Layering gold leaf over a surface is called gold leafing or gilding. Traditional water gilding is the most difficult and highly regarded form of gold leafing. It has remained virtually unchanged for hundreds of years and is still done by hand. In art Gold leaf is sometimes used in art in a "raw" state, without a gilding process. In cultures including the European Bronze Age it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goldschläger
''Goldschläger'' is a Swiss cinnamon schnapps (43.5% alcohol by volume or 87 proof; originally it was 53.5% alcohol or 107 proof), a liqueur with very thin, yet visible flakes of gold floating in it. The actual amount of gold has been measured at approximately in a one-litre bottle. , this amounts to €0.66/US$0.75 on the international gold market. Goldschläger was produced in Switzerland until the 1990s. The brand was acquired by Diageo, which moved production to Italy. In 2008, Global Brands Limited (UK) purchased the brand as part of its portfolio and production returned to Switzerland. In November 2018, Diageo agreed to sell Goldschläger as part of a 19-brand portfolio of spirits brands to the New Orleans–based U.S. distiller Sazerac Company Sazerac Company, Inc is a privately held American alcoholic beverage company headquartered in Metairie in the metropolitan area of New Orleans, Louisiana, but with its principal office in Louisville, Kentucky. The company ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphosed limestone, but its use in stonemasonry more broadly encompasses unmetamorphosed limestone. Marble is commonly used for sculpture and as a building material. Etymology The word "marble" derives from the Ancient Greek (), from (), "crystalline rock, shining stone", perhaps from the verb (), "to flash, sparkle, gleam"; R. S. P. Beekes has suggested that a " Pre-Greek origin is probable". This stem is also the ancestor of the English word "marmoreal," meaning "marble-like." While the English term "marble" resembles the French , most other European languages (with words like "marmoreal") more closely resemble the original Ancient Greek. Physical origins Marble is a rock resulting from metamorphism of sedimentary carbonate rocks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Forming
Forming, metal forming, is the metalworking process of fashioning metal parts and objects through mechanical deformation; the workpiece is reshaped without adding or removing material, and its mass remains unchanged. Forming operates on the materials science principle of plastic deformation, where the physical shape of a material is permanently deformed. Characteristics Metal forming tends to have more uniform characteristics across its subprocesses than its contemporary processes, cutting and joining. On the industrial scale, forming is characterized by: * Very high loads and stresses required, between 50 and () * Large, heavy, and expensive machinery in order to accommodate such high stresses and loads * Production runs with many parts, to maximize the economy of production and compensate for the expense of the machine tools Forming processes Forming processes tend to be categorised by differences in effective stresses. These categories and descriptions are highly simplif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium ( gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Pathé
British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, the English language as spoken and written in the United Kingdom or, more broadly, throughout the British Isles * Celtic Britons, an ancient ethno-linguistic group * Brittonic languages, a branch of the Insular Celtic language family (formerly called British) ** Common Brittonic, an ancient language Other uses *'' Brit(ish)'', a 2018 memoir by Afua Hirsch *People or things associated with: ** Great Britain, an island ** United Kingdom, a sovereign state ** Kingdom of Great Britain (1707–1800) ** United Kingdom of Great Britain and Ireland (1801–1922) See also * Terminology of the British Isles * Alternative names for the British * English (other) * Britannic (other) * British Isles * Brit (other) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tin(IV) Sulfide
Tin(IV) sulfide is a compound with the formula . The compound crystallizes in the cadmium iodide motif, with the Sn(IV) situated in "octahedral holes' defined by six sulfide centers. It occurs naturally as the rare mineral berndtite. It is useful as semiconductor material with band gap 2.2 eV. Reactions The compound precipitates as a brown solid upon the addition of to solutions of tin(IV) species. This reaction is reversed at low pH. Crystalline has a bronze color and is used in decorative coatingHolleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. . where it is known as mosaic gold. The material also reacts with sulfide salts to give a series of thiostannates Sulfidostannates, or thiostannates are chemical compounds containing anions composed of tin linked with sulfur. They can be considered as stannates with sulfur substituting for oxygen. Related compounds include the thiosilicates, and thiogermannat ... with the formula . A simplifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaic Gold
Mosaic gold or bronze powder refers to tin(IV) sulfide as used as a pigment in bronzing and gilding wood and metal work. It is obtained as a yellow scaly crystalline powder. The alchemists referred to it as aurum musivum, or aurum mosaicum. The term mosaic gold has also been used to refer to ormolu and to cut shapes of gold leaf, some darkened for contrast, arranged as a mosaic. The term bronze powder may also refer to powdered bronze alloy. Mosaic gold appeared in Europe after the 14th century. Alchemists prepared it by combining mercury, tin, sal ammoniac, and sublimated sulfur (fleur de soufre), grinding, mixing, then setting them for three hours in a sand heat. The dirty sublimate being taken off, aurum mosaicum was found at the bottom of the matrass. In the past it was used for medical purposes in most chronic and nervous ailments, and particularly convulsions of children; however, it is no longer recommended for any medical uses. See also * List of inorganic pigments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Leaf
A metal leaf, also called composition leaf or schlagmetal, is a thin foil used for gilding and other forms of decoration. Metal leaves can come in many different shades. Some metal leaves may look like gold leaf but do not contain any real gold. This type of metal leaf is often referred to as imitation leaf. Metal leaves are usually made of gold (including many alloys), silver, copper, aluminium, brass (sometimes called " Dutch metal" typically 85% Copper and 15% zinc) or palladium, sometimes also platinum. Vark is a type of silver leaf used for decoration in Indian cuisine. Goldbeating, the technique of producing metal leaves, has been known for more than 5,000 years. A small gold nugget 5 mm in diameter can be expanded to about 20,000 times its initial surface through hammering, producing a gold foil surface of about one half square meter with a thickness of 0.2–0.3 μm. Nanjing gold leaf forging technique History This is a traditional handicraft in Nanjing, produced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
