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Coin Center
A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to facilitate trade. They are most often issued by a government. Coins often have images, numerals, or text on them. ''Obverse'' and its opposite, ''reverse'', refer to the two flat faces of coins and medals. In this usage, ''obverse'' means the front face of the object and ''reverse'' means the back face. The obverse of a coin is commonly called ''heads'', because it often depicts the head of a prominent person, and the reverse ''tails''. Coins are usually made of metal or an alloy, or sometimes of man-made materials. They are usually disc shaped. Coins, made of valuable metal, are stored in large quantities as bullion coins. Other coins are used as money in everyday transactions, circulating alongside banknotes. Usually the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barter
In trade, barter (derived from ''baretor'') is a system of exchange in which participants in a transaction directly exchange goods or services for other goods or services without using a medium of exchange, such as money. Economists distinguish barter from gift economies in many ways; barter, for example, features immediate reciprocal exchange, not one delayed in time. Barter usually takes place on a bilateral basis, but may be multilateral (if it is mediated through a trade exchange). In most developed countries, barter usually exists parallel to monetary systems only to a very limited extent. Market actors use barter as a replacement for money as the method of exchange in times of monetary crisis, such as when currency becomes unstable (such as hyperinflation or a deflationary spiral) or simply unavailable for conducting commerce. No ethnographic studies have shown that any present or past society has used barter without any other medium of exchange or measurement, and an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achaemenid Empire
The Achaemenid Empire or Achaemenian Empire (; peo, 𐎧𐏁𐏂, , ), also called the First Persian Empire, was an ancient Iranian empire founded by Cyrus the Great in 550 BC. Based in Western Asia, it was contemporarily the largest empire in history, spanning a total of from the Balkans and Egypt in the west to Central Asia and the Indus Valley in the east. Around the 7th century BC, the region of Persis in the southwestern portion of the Iranian plateau was settled by the Persians. From Persis, Cyrus rose and defeated the Median Empire as well as Lydia and the Neo-Babylonian Empire, marking the formal establishment of a new imperial polity under the Achaemenid dynasty. In the modern era, the Achaemenid Empire has been recognized for its imposition of a successful model of centralized, bureaucratic administration; its multicultural policy; building complex infrastructure, such as road systems and an organized postal system; the use of official languages across ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ingot
An ingot is a piece of relatively pure material, usually metal, that is cast into a shape suitable for further processing. In steelmaking, it is the first step among semi-finished casting products. Ingots usually require a second procedure of shaping, such as cold/hot working, cutting, or milling to produce a useful final product. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods. Precious metal ingots can be used as currency (with or without being processed into other shapes), or as a currency reserve, as with gold bars. Types Ingots are generally made of metal, either pure or alloy, heated past its melting point and cast into a bar or block using a mold chill method. A special case are polycrystalline or single crystal ingots made by pulling from a molten melt. Single crystal Single crystal ingots (called boules) of materials are grown (crystal growth) using methods such as the Czo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minoan Copper Ingot From Zakros, Crete
The Minoan civilization was a Bronze Age Aegean civilization on the island of Crete and other Aegean Islands, whose earliest beginnings were from 3500BC, with the complex urban civilization beginning around 2000BC, and then declining from 1450BC until it ended around 1100BC, during the early Greek Dark Ages, part of a wider bronze age collapse around the Mediterranean. It represents the first advanced civilization in Europe, leaving behind a number of massive building complexes, sophisticated art, and writing systems. Its economy benefited from a network of trade around much of the Mediterranean. The civilization was rediscovered at the beginning of the 20th century through the work of British archaeologist Sir Arthur Evans. The name "Minoan" derives from the mythical King Minos and was coined by Evans, who identified the site at Knossos with the labyrinth of the Minotaur. The Minoan civilization has been described as the earliest of its kind in Europe, and historian Will Dura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porcelain
Porcelain () is a ceramic material made by heating substances, generally including materials such as kaolinite, in a kiln to temperatures between . The strength and translucence of porcelain, relative to other types of pottery, arises mainly from vitrification and formation of the mineral mullite within the body at these high temperatures. Though definitions vary, porcelain can be divided into three main categories: hard-paste, soft-paste, and bone china. The category that an object belongs to depends on the composition of the paste used to make the body of the porcelain object and the firing conditions. Porcelain slowly evolved in China and was finally achieved (depending on the definition used) at some point about 2,000 to 1,200 years ago; it slowly spread to other East Asian countries, then to Europe, and eventually to the rest of the world. Its manufacturing process is more demanding than that for earthenware and stoneware, the two other main types of pottery, and it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coinage Metals
The coinage metals comprise, at a minimum, those metallic chemical elements which have historically been used as components in alloys used to mint coins. The term is not perfectly defined, however, since a number of metals have been used to make "demonstration coins" which have never been used to make monetized coins for any nation-state, but could be. Some of these elements would make excellent coins in theory (for example, zirconium), but their status as coin metals is not clear. In general, because of problems caused when coin metals are intrinsically valuable as commodities, there has been a trend in the 21st century toward use of coinage metals of only the least exotic and expensive types. History Historically, most coinage metals (or alloys) are from the three nonradioactive members of group 11 of the periodic table: copper, silver and gold, the copper usually being augmented with tin and often other metals to form bronze. Gold, silver and bronze or copper were the coinag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krugerrand
The Krugerrand (; ) is a South African coin, first minted on 3 July 1967 to help market South African gold and produced by Rand Refinery and the South African Mint. The name is a compound of ''Paul Kruger'', the former President of the South African Republic (depicted on the obverse), and ''rand'', the South African unit of currency. On the reverse side of the Krugerrand is a pronking springbok, South Africa's national animal. By 1980 the Krugerrand accounted for more than 90% of the global gold coin market and was the number one choice for investors buying gold. However, during the 1980s and 1990s, Krugerrands fell out of favor as some western countries forbade import of the Krugerrand because of its association with the apartheid government of South Africa.Bob Secter (02 Oct 1985Reagan Bans Imports of S. Africa Krugerrand The Los Angeles Times, accessed 28 June 2018 Although gold Krugerrand coins have no face value, they are considered legal tender in South Africa by the Sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Gold Maple Leaf
The Canadian Gold Maple Leaf (GML) is a gold bullion coin that is issued annually by the Government of Canada. It is produced by the Royal Canadian Mint. The Gold Maple Leaf is legal tender with a face value of 50 Canadian dollars. The market value of the metal varies, depending on the spot price of gold. Having a .9999 millesimal fineness (24 carats), in some cases .99999, the coin is among the purest official bullion coins worldwide. The standard version has a weight of minimum 1 troy ounce (31.10 grams). Other sizes and denominations include 1 gram, ($0.50), ($1), ($5), ($10), and ($20). The Gold Maple Leaf's obverse and reverse display, respectively, the profile of Queen Elizabeth II of Canada and the Canadian Maple Leaf. In 2013 and 2015, new security features were introduced. In 2013, a laser-micro-engraved textured maple leaf was added on a small area of the reverse (Maple Leaf) side of the coin. In the centre of this mark is the numeral denoting the coin's year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Gold Eagle
The American Gold Eagle is an official gold bullion coin of the United States. Authorized under the Gold Bullion Coin Act of 1985, it was first released by the United States Mint in 1986. Because the term "eagle" also is the official United States designation for pre-1933 ten dollars gold coins, the weight of the bullion coin is typically used when describing American Gold Eagles (e.g., "1/2-ounce American Gold Eagle") to avoid confusion. This is particularly true with the 1/4-oz American Gold Eagle, which has a marked face value of ten dollars. Details Offered in 1/10 oz, 1/4 oz, 1/2 oz, and 1 oz denominations, these coins are guaranteed by the U.S. government to contain the stated amount of actual gold weight in troy ounces. By law, the gold must come from sources in the United States, alloyed with silver and copper to produce a more wear-resistant coin. In addition, sales of these and other specie coins from the US Mint are mandated, at least in part, to pay off the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sovereign (British Coin)
The sovereign is a British gold coin with a nominal value of one pound sterling (£1) and contains 0.2354 troy oz of pure gold. Struck since 1817, it was originally a circulating coin that was accepted in Britain and elsewhere in the world; it is now a bullion coin and is sometimes mounted in jewellery. In addition, circulation strikes and proof examples are often collected for their numismatic value. In most recent years, it has borne the design of Saint George and the Dragon on the reverse; the initials () of the designer, Benedetto Pistrucci, are visible to the right of the date. The coin was named after the English gold sovereign, which was last minted about 1603, and originated as part of the Great Recoinage of 1816. Many in Parliament believed a one-pound coin should be issued rather than the 21-shilling guinea that was struck until that time. The Master of the Mint, William Wellesley Pole had Pistrucci design the new coin; his depiction was also used for other go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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