Silver is a metallic element with symbol Ag and atomic number 47. The symbol Ag stems from Latin argentum, derived from the Greek ὰργὀς, a soft, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earths crust in the pure, free form, as an alloy with gold and other metals. Most silver is produced as a byproduct of copper, lead, Silver is more abundant than gold, but it is much less abundant as a native metal. Its purity is measured on a per mille basis, a 94%-pure alloy is described as 0.940 fine. As one of the seven metals of antiquity, silver has had a role in most human cultures. Silver has long valued as a precious metal. Silver metal is used in many premodern monetary systems in bullion coins, Silver is used in numerous applications other than currency, such as solar panels, water filtration, ornaments, high-value tableware and utensils, and as an investment medium. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings, Silver compounds are used in photographic film and X-rays.
Dilute silver nitrate solutions and other compounds are used as disinfectants and microbiocides, added to bandages and wound-dressings, catheters. Silver is similar in its physical and chemical properties to its two neighbours in group 11 of the periodic table and gold. This distinctive electron configuration, with an electron in the highest occupied s subshell over a filled d subshell. Silver is a soft and malleable transition metal. Silver crystallizes in a cubic lattice with bulk coordination number 12. Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a covalent character and are relatively weak and this observation explains the low hardness and high ductility of single crystals of silver. Silver has a brilliant white metallic luster that can take a polish. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm, at wavelengths shorter than 450 nm, silvers reflectivity is inferior to that of aluminium and drops to zero near 310 nm.
The electrical conductivity of silver is the greatest of all metals, greater even than copper, during World War II in the US,13540 tons of silver were used in electromagnets for enriching uranium, mainly because of the wartime shortage of copper
An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character, an alloy may be a solid solution of metal elements or a mixture of metallic phases. Intermetallic compounds are alloys with a stoichiometry and crystal structure. Zintl phases are sometimes considered alloys depending on bond types. Alloys are used in a variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties, in other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, brass, duralumin, the alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the arrangement that forms the alloy. They can be classified as homogeneous, or heterogeneous or intermetallic. An alloy is a mixture of elements, which forms an impure substance that retains the characteristics of a metal.
Alloys are made by mixing two or more elements, at least one of which is a metal and this is usually called the primary metal or the base metal, and the name of this metal may be the name of the alloy. The other constituents may or may not be metals but, when mixed with the base, they will be soluble. The mechanical properties of alloys will often be different from those of its individual constituents. A metal that is very soft, such as aluminium, can be altered by alloying it with another soft metal. Although both metals are soft and ductile, the resulting aluminium alloy will have much greater strength. Adding a small amount of carbon to iron trades its great ductility for the greater strength of an alloy called steel. Due to its strength, but still substantial toughness, and its ability to be greatly altered by heat treatment, steel is one of the most useful. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel
The tetradrachm was an Ancient Greek silver coin equivalent to four drachmae. In Athens it replaced the earlier type of didrachms and it was in wide circulation from c.510 to c.38 BC. The transition from didrachms to tetradrachms occurred during c, 525–510 BC, the abandonment of the heraldic-type didrachms and the Archaic tetradrachms of the polis of Athens apparently took place shortly after the Battle of Salamis,480 BC. This transition is supported by the discovery of contemporary coin hoards, the Athenian tetradrachm was widely used in transactions throughout the ancient Greek world, including in cities politically unfriendly to Athens. Athens had silver mines in state ownership, which provided the bullion, most well known were the silver mines of Laurium at a close distance from Athens. According to Philochorus, it was known as glaux throughout the ancient world, the design was kept essentially unchanged for over two centuries, by which time it had become stylistically archaic. To differentiate their currency from the coinage of Aegina using the Aeginetic stater of about 12.3 grams.
The tetradrachms use as a currency was adopted by many other city-states of the ancient Greece, Asia Minor, Magna Grecia. With the armies of Alexander the Great it spread to the Greek-influenced areas of present-day Iran, Coin Coin in the fishs mouth Greek drachma List of historical currencies Stater Pictures of Athenian tetradrachms
The Antoninianus, or radiate, was a coin used during the Roman Empire thought to have been valued at 2 denarii. It was initially silver, but was slowly debased to bronze with a silver content. Antoniniani depicting females, usually the wife, featured the bust resting upon a crescent moon. Even at its introduction the silver content was only equal to 1.5 denarii and this helped to create inflation, people rapidly hoarded the denarii, while both buyers and sellers recognised the new coin had a lower intrinsic value and elevated their prices to compensate. Each new issue of the Antoninianus thus had less silver in it than the last, in 271 Aurelian increased the average weight of the Antoninianus. This was carried out for a short time and this period was when the enigmatic XXI was first marked on the reverse of the Antoninianus. The true meaning of this series of numbers is still a topic of debate, by the late 3rd century the coins were almost entirely made of bronze from melted down old issues like the sestertius.
Vast quantities were being minted, with a proportion of the stocks being contemporary forgeries, often with blundered legends. Individual coins were by practically worthless and were lost or discarded by the millions, today most of these coins are extremely common finds, with a few more scarce examples including Aemilianus, Marcus Aurelius Marius and Regalianus. The situation was not unlike the hyperinflation of the Weimar Republic in 1920s Germany, the coin ceased to be used by the end of the 3rd century when a series of coinage reforms attempted to arrest the decline by issuing new types. Modern numismatists use this name for the coin because it is not known what it was called in antiquity, an ancient Roman document called the Historia Augusta refers to silver coins named after an Antoninus on several occasions
Civil wars and executions continued, culminating in the victory of Octavian, Caesars adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavians power was unassailable and in 27 BC the Roman Senate formally granted him overarching power, the imperial period of Rome lasted approximately 1,500 years compared to the 500 years of the Republican era. The first two centuries of the empires existence were a period of unprecedented political stability and prosperity known as the Pax Romana, following Octavians victory, the size of the empire was dramatically increased. After the assassination of Caligula in 41, the senate briefly considered restoring the republic, under Claudius, the empire invaded Britannia, its first major expansion since Augustus. Vespasian emerged triumphant in 69, establishing the Flavian dynasty, before being succeeded by his son Titus and his short reign was followed by the long reign of his brother Domitian, who was eventually assassinated.
The senate appointed the first of the Five Good Emperors, the empire reached its greatest extent under Trajan, the second in this line. A period of increasing trouble and decline began with the reign of Commodus, Commodus assassination in 192 triggered the Year of the Five Emperors, of which Septimius Severus emerged victorious. The assassination of Alexander Severus in 235 led to the Crisis of the Third Century in which 26 men were declared emperor by the Roman Senate over a time span. It was not until the reign of Diocletian that the empire was fully stabilized with the introduction of the Tetrarchy, which saw four emperors rule the empire at once. This arrangement was unsuccessful, leading to a civil war that was finally ended by Constantine I. Constantine subsequently shifted the capital to Byzantium, which was renamed Constantinople in his honour and it remained the capital of the east until its demise. Constantine adopted Christianity which became the state religion of the empire. However, Augustulus was never recognized by his Eastern colleague, and separate rule in the Western part of the empire ceased to exist upon the death of Julius Nepos.
The Eastern Roman Empire endured for another millennium, eventually falling to the Ottoman Turks in 1453, the Roman Empire was among the most powerful economic, cultural and military forces in the world of its time. It was one of the largest empires in world history, at its height under Trajan, it covered 5 million square kilometres. It held sway over an estimated 70 million people, at that time 21% of the entire population. Throughout the European medieval period, attempts were made to establish successors to the Roman Empire, including the Empire of Romania, a Crusader state. Rome had begun expanding shortly after the founding of the republic in the 6th century BC, then, it was an empire long before it had an emperor
A medal may be awarded to a person or organization as a form of recognition for sporting, scientific, academic, or various other achievements. Military awards and decorations are more precise terms for types of state decoration. Medals may be created for sale to commemorate particular individuals or events, an artist who creates medals or medallions is called a medallist or medalist. There are devotional medals which may be worn for religious reasons, Medals have long been popular collectible items either as a variety of exonumia or of militaria. Medallions may be called table medals because they are too large to be worn and can only be displayed on a wall, table top, the word medallion has the same ultimate derivation, but this time through the Italian medaglione, meaning large medal. The main or front surface of a medal is termed the obverse, the reverse, or back surface of the medal, is not always used and may be left blank or may contain a secondary design. It is not uncommon to only an artistic rendering on the obverse, while all details.
The rim is only occasionally employed to display an inscription such as a motto, privy mark, engraver symbol, assayer’s marking. Medals that are intended to be hung from a ribbon include a suspension piece at the crest with which to loop a suspension ring through. It is through the ring that a ribbon is run or folded so the medal may hang pendent, Medals pinned to the breast use only a small cut of ribbon that is attached to a top bar where the brooch pin is affixed. Top bars may be hidden under the ribbon so they are not visible, be a device from which the ribbon attaches. Some top bars are elaborate and contain a whole design unto themselves, Medals that are made with inexpensive material might be gilded, silver-plated, chased, or finished in a variety of other ways to improve their appearance. Medals have made of rock, ivory, porcelain, terra cotta, wood, enamel, lacquerware. Honorary awards, as a button, which it is custom to give the kings kinsmen. Roman emperors used both military awards of medals, and political gifts of medallions that were very large coins, usually in gold or silver.
Both these and actual golden coins were often set as pieces of jewellery, the bracteate is a type of thin gold medal, usually plain on the reverse, found in Northern Europe from the so-called Dark Ages or Migration Period. They often have suspension loops and were intended to be worn on a chain as jewellery. They imitate, at a distance, Roman imperial coins and medallions, the surviving example is mounted for wearing as jewellery
A metal is a material that is typically hard, opaque and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible and ductile, about 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms, astrophysicists use the term metal to collectively describe all elements other than hydrogen and helium, the simplest two, in a star. The star fuses smaller atoms, mostly hydrogen and helium, to larger ones over its lifetime. In that sense, the metallicity of an object is the proportion of its matter made up of all chemical elements. Many elements and compounds that are not normally classified as metals become metallic under high pressures, the atoms of metallic substances are typically arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, and hexagonal close-packed.
In bcc, each atom is positioned at the center of a cube of eight others, in fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layers differs. Some metals adopt different structures depending on the temperature, atoms of metals readily lose their outer shell electrons, resulting in a free flowing cloud of electrons within their otherwise solid arrangement. This provides the ability of metallic substances to easily transmit heat, while this flow of electrons occurs, the solid characteristic of the metal is produced by electrostatic interactions between each atom and the electron cloud. This type of bond is called a metallic bond, Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales. Examples,4 Na + O2 →2 Na2O2 Ca + O2 →2 CaO4 Al +3 O2 →2 Al2O3, the transition metals are slower to oxidize because they form a passivating layer of oxide that protects the interior. Others, like palladium and gold, do not react with the atmosphere at all, some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades.
The oxides of metals are generally basic, as opposed to those of nonmetals, exceptions are largely oxides with very high oxidation states such as CrO3, Mn2O7, and OsO4, which have strictly acidic reactions. Painting, anodizing or plating metals are good ways to prevent their corrosion, however, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. Water and the two form an electrochemical cell, and if the coating is less reactive than the coatee. Metals in general have high conductivity, high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving, in terms of optical properties, metals are shiny and lustrous. Sheets of metal beyond a few micrometres in thickness appear opaque, although most metals have higher densities than most nonmetals, there is wide variation in their densities, lithium being the least dense solid element and osmium the densest
Bullion is gold bars, silver bars, and other bars or ingots of precious metal. The word bullion comes from the French Minister of Finance under Louis XIII, the value of bullion is typically determined by the value of its precious metals content, which is defined by its purity and mass. It is weighed extremely accurately, retailers may sometimes market ingots and bars of base metals, such as copper and aluminium as bullion, but this is not a widely accepted definition. The specifications of bullion are often regulated by market bodies or legislation, in the European Union, the minimum purity for gold bullion, which is treated as investment gold with regards to taxation, is 99. 5% for gold bullion bars and 90% for bullion coins. The London bullion market is a market for wholesale trading of gold. The London Bullion Market Association coordinates activities of its members and other participants in the London bullion market, the LBMA sets and promotes quality standards for gold and silver bullion bars.
The minimum acceptable fineness of the Good Delivery Bars is 99. 5% for gold bars and 99. 9% for silver bars, Bullion coins describe contemporary precious metal coins minted by official agencies for investment purposes. Historically, most currency were in the form of coins, silver. Some bullion coins have been used as currency throughout the 20th century, like the Maria Theresa thaler, modern bullion coins generally do not enter common circulation despite having legal tender status and a nominal face value. Some modern bullion coins, such as the gold and silver American eagle, are produced as both business strike and collectible proof and uncirculated versions. Business strikes typically are sold at prices commensurate with their precious metal content, in some cases the grade and mintages of business strike coins can affect their value, so that they are considered numismatic rather than bullion items. A range of market participants is active in the bullion markets, fabricators, refiners. They provide facilities for the refining, assaying, transporting and vaulting of gold, for example, shares of the world’s largest Gold exchange-traded fund, the SPDR Gold Shares represent ownership in vaulted gold bullion.
Private individuals use bullion primarily as an investment or potential store of value, Gold bullion and silver bullion are the most important forms of physical precious metals investments. Bullion investments can be considered as insurance against inflation or economic turmoil, compared to numismatic coins, bullion bars or bullion coins can typically be purchased and traded at lower margins and their trading prices are closer to the values of the contained precious metals
These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as stiffness, ductility, or machinability. The archeological period where bronze was the hardest metal in use is known as the Bronze Age. In the ancient Near East this began with the rise of Sumer in the 4th millennium BC, with India and China starting to use bronze around the same time, everywhere it gradually spread across regions. The Bronze Age was followed by the Iron Age starting from about 1300 BC and reaching most of Eurasia by about 500 BC, the discovery of bronze enabled people to create metal objects which were harder and more durable than previously possible. Bronze tools, weapons and building such as decorative tiles were harder and more durable than their stone. It was only that tin was used, becoming the major ingredient of bronze in the late 3rd millennium BC. Tin bronze was superior to arsenic bronze in that the process could be more easily controlled. Also, unlike arsenic, metallic tin and fumes from tin refining are not toxic, the earliest tin-alloy bronze dates to 4500 BCE in a Vinča culture site in Pločnik.
Other early examples date to the late 4th millennium BC in Africa and some ancient sites in China, ores of copper and the far rarer tin are not often found together, so serious bronze work has always involved trade. Tin sources and trade in ancient times had a influence on the development of cultures. In Europe, a source of tin was the British deposits of ore in Cornwall. In many parts of the world, large hoards of bronze artefacts are found, suggesting that bronze represented a store of value, in Europe, large hoards of bronze tools, typically socketed axes, are found, which mostly show no signs of wear. With Chinese ritual bronzes, which are documented in the inscriptions they carry and from other sources and these were made in enormous quantities for elite burials, and used by the living for ritual offerings. Pure iron is soft, and the process of beating and folding sponge iron to wrought iron removes from the metal carbon. Careful control of the alloying and tempering eventually allowed for wrought iron with properties comparable to modern steel, Bronze was still used during the Iron Age, and has continued in use for many purposes to the modern day.
Among other advantages, it does not rust, the weaker wrought iron was found to be sufficiently strong for many uses. Archaeologists suspect that a disruption of the tin trade precipitated the transition. The population migrations around 1200–1100 BC reduced the shipping of tin around the Mediterranean, limiting supplies, there are many different bronze alloys, but typically modern bronze is 88% copper and 12% tin
A bawbee was a Scottish halfpenny. The word means a debased copper coin, valued at six pence Scots and they were hammered until 1677, when they were produced upon screw presses. The bawbee was introduced by James V in 1538, valued at sixpence and these carry his I5 monogram flanking a crowned thistle, and a large saltire on the reverse with a central crown. There was smaller half bawbee and quarter bawbee, around the year 1544 his widow Mary of Guise minted bawbees at Stirling Castle, with the MR cipher, and the cross potent with crosslets of Lorraine on the reverse. The first bawbees of Mary, Queen of Scots issued by the mint at Holyroodhouse in Edinburgh carried the cinquefoil emblems of Regent Arran. The issue of King Charles II was a coin of copper with the reverse inscription Nemo me impune lacessit. This motto is still in use today on the edge of the circulating Scottish one Pound Sterling coins, the motto is around a crowned thistle followed by the date. This coin was valued at six pence Scots or half an English penny and it was metaphorically used for a fortune by Sir Alexander Boswell, the son of the more famous James Boswell, the biographer of Dr.
Johnson. Brewers lists Jennys Bawbee as meaning a marriage portion, the word was still current in the 20th century and continues to be used to refer to Bawbee Baps or cakes in Aberdeen. A popular song, The Crookit Bawbee, was recorded by The Alexander Brothers and Kenneth McKellar amongst others, inevitably the rich suitor turns out to be the laddie returned to his love. Three plumps and a wallop for ae bawbee, the tale is that the people of Kirkmahoe were so poor, they could not afford to put any meat into their broth. He wrapped it in a cabbage-leaf and took it home and this was called a gustin bone, and was supposed to give a rich gust to the broth. The cobbler found his gustin bone very profitable and that there was such a laird is quite certain from the Treasurers account, September 7th,1541, In argento receptis a Jacobo Atzinsone, et Alexandro Orok de Sillebawby respective. This Master of the Mint, appointed by James V, was responsible for the introduction of a coin valued at six. Sillebawby was a farm in the parish of Burntisland in Fife and its name takes various forms throughout its recorded history, Slebalbe, Selybawbey are some early examples.
The examples Silverbabie, Silver-baby and Silverbarton may have arisen from a nickname marking the connection to the silver coin, Brewers gives an alternative etymology, and states its origin from French, bas billon, but this is a kind of speculative folk-etymology. Bodle Plack Pound Scots Scottish coinage Holmes, Scottish Coins, A History of Small Change in Scotland. NMS Publishing ISBN 1-901663-02-7 MacKay, Charles, a Dictionary of Lowland Scotch Brewers Dictionary of Phrase and Fable Bawbee at Brewers Phrase and Fable