Silver in the context of Astatine

The mines of Laurion (or Lavrion) are ancient mines located in southern Attica between Thorikos and Cape Sounion, approximately 50 kilometers south of the center of Athens, in Greece. The mines are best known for producing silver, but they were also a source of copper and lead. A number of remnants of these mines (shafts, galleries, surface workshops) are still present in the region.

The mines were exploited in prehistoric times as a source of copper and galena, a lead ore. In the classical period, mining in the area resumed. The Athenians used large numbers of slaves to mine the area, with the silver produced contributing significantly to the city's wealth. Abandoned in the 1st century BC, the mines were reactivated in 1864 and mined for their lead by French and Greek companies until 1978.

Lavrio, Lavrion or Laurium (Greek: Λαύριο; Ancient Greek: Λαύρειον (later Λαύριον); from Middle Ages until 1908: Εργαστήρια Ergastiria) is a town in southeastern part of Attica, Greece. It is part of Athens metropolitan area and the seat of the municipality of Lavreotiki. Laurium was famous in Classical antiquity for its silver mines, which was one of the chief sources of revenue of the Athenian state. The metallic silver was mainly used for coinage. The Archaeological Museum of Lavrion shows much of the story of these mines.

It is located about 60 km SE of Athens city center, SE of Keratea and N of Cape Sounio. Laurium is situated on a bay overlooking the island of Makronisos (ancient times: Helena) in the east. The port is in the middle and gridded streets cover the residential area of Lavrio. GR-89 runs through Lavrio and ends south in Sounio.

The Iron Age (c. 1200 – c. 550 BC) is the final epoch of the three historical Metal Ages, after the Copper Age and Bronze Age. It has also been considered as the final age of the three-age division starting with prehistory (before recorded history) and progressing to protohistory (before written history). In this usage, it is preceded by the Stone Age (subdivided into the Paleolithic, Mesolithic and Neolithic) and Bronze Age. These concepts originated for describing Iron Age Europe and the ancient Near East. In the archaeology of the Americas, a five-period system is conventionally used instead; indigenous cultures there did not develop an iron economy in the pre-Columbian era, though some did work copper and silver. Indigenous metalworking arrived in Australia with European contact. Although meteoric iron has been used for millennia in many regions, the beginning of the Iron Age is defined locally around the world by archaeological convention when the production of smelted iron (especially steel tools and weapons) replaces their bronze equivalents in common use.

In Anatolia and the Caucasus, or Southeast Europe, the Iron Age began c. 1300 BC. In the ancient Near East, this transition occurred simultaneously with the Late Bronze Age collapse, during the 12th century BC. The technology soon spread throughout the Mediterranean basin region and to South Asia between the 12th and 11th centuries BC. Its further spread to Central Asia, Eastern Europe, and Central Europe was somewhat delayed, and Northern Europe was not reached until c. the 5th century BC.

A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer.

In more physical terms, a latent image is a small cluster of metallic silver atoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called printing out the image. On the other hand, the formation of a visible image by the action of photographic developer is called developing out the image.

In the processing of photographic films, plates or papers, the photographic developer (or just developer) is one or more chemicals that convert the latent image to a visible image. Developing agents achieve this conversion by reducing the silver halides, which are pale-colored, into silver metal, which is black when in the form of fine particles. The conversion occurs within the gelatine matrix. The special feature of photography is that the developer acts more quickly on those particles of silver halide that have been exposed to light. When left in developer, all the silver halides will eventually be reduced and turn black. Generally, the longer a developer is allowed to work, the darker the image.

Silver coins are one of the oldest mass-produced form of coinage. Silver has been used as a coinage metal since the times of the Greeks; their silver drachmas were popular trade coins. The ancient Persians used silver coins between 612–330 BC. Before 1797, British pennies were made of silver.

As with all collectible coins, many factors determine the value of a silver coin, such as its rarity, demand, condition and the number originally minted. Ancient silver coins coveted by collectors include the Denarius and Miliarense, while more recent collectible silver coins include the Morgan Dollar and the Spanish Milled Dollar.

The antoninianus or pre-reform 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 minimal silver content. The coin was introduced by Caracalla in early 215 AD. It was silver, similar to the denarius, except that it was slightly larger and featured the emperor wearing a radiate crown, indicating it was a double denomination. Antoniniani depicting women (usually the emperor's wife) featured the bust resting upon a crescent moon.

Even at its introduction, the silver content of the antoninianus was only equal to 1.5 denarii. This created inflation: people rapidly hoarded the denarii (Gresham's law), while both buyers and sellers recognized the new coin had a lower intrinsic value and elevated their prices to compensate. Silver bullion supplies began running short because the Roman Empire was no longer conquering new territory, the Iberian silver mines had been exhausted, and a series of soldier emperors and usurpers needed coin to pay their troops and buy their loyalty. Each new issue of the antoninianus thus had less silver in it than the last, and thus contributed to ever-increasing inflation.

Africa has a large quantity of natural resources, including diamonds, sugar, salt, gold, iron, cobalt, uranium, copper, bauxite, silver, petroleum, natural gas and cocoa beans, but also tropical timber and tropical fruit.

Recently discovered oil reserves have increased the importance of the commodity in African economies. Nigeria, Angola, Republic of the Congo, Equatorial Guinea, Algeria, Libya, Egypt, and South Sudan are among the largest oil producers in Africa. The United States and European countries took most of the Democratic Republic of the Congo's (DRC) oil production. Oil is provided by both continental and offshore productions. Sudan's oil exports in 2010 are estimated by the United States Department of State at US$9 billion.

Ballaios (Ancient Greek: Βαλλαῖος; ruled c. 260 – c. 230 BC) was an Illyrian king of the Ardiaei tribe. Attested only in coinage, Ballaios is considered as the predecessor of Agron. He is considered to have been a powerful and influential king as testified by the abundance of his silver and bronze coinage found along both coasts of the Adriatic. A hoard found in 2010 is one of the biggest hoards of ancient coins known, not only from Illyria. The capital of Ballaios' kingdom was Rhizon.

His silver issues are rare, but bronze coins, without the royal title, occur on Hvar, both in single finds and in hoards, and at Rhizon in a different series bearing the royal title. In the city of Ulcinj there is still a fully functioning water source bearing his name: "Kroni i Ballos". The coins of Ballaios were widely imitated in the region, sometimes so crudely that they are unintelligible.

A silver medal, in sports and other similar areas involving competition, is a medal made of, or plated with, silver awarded to the second-place finisher, or runner-up, of contests or competitions such as the Olympic Games, Commonwealth Games, etc. The outright winner receives a gold medal and the third place a bronze medal. More generally, silver is traditionally a metal sometimes used for all types of high-quality medals, including artistic ones.

Byzantine currency, money used in the Eastern Roman Empire after the fall of the West, consisted of mainly two types of coins: gold solidi and hyperpyra and a variety of clearly valued bronze coins. By the 15th century, the currency was issued only in debased silver stavrata and minor copper coins with no gold issue. The Byzantine Empire established and operated several mints throughout its history. Aside from the main metropolitan mint in the capital, Constantinople, a varying number of provincial mints were also established in other urban centres, especially during the 6th century.

Most provincial mints except for Syracuse were closed or lost to Arab Muslim invasions in the Mediterranean Region by the mid-7th century onwards. After the loss of Syracuse in 878, Constantinople became the sole mint for gold and silver coinage until the late 11th century, when major provincial mints began to re-appear. Many mints, both imperial and, as the Byzantine Empire fragmented, belonging to autonomous local rulers, were operated in the 12th to 14th centuries. Constantinople and Trebizond, capital of the independent Empire of Trebizond (1204–1461), survived until the invasion of Anatolia by the Ottoman Turks in the mid-15th century.

Thorikos or Thoricus (Ancient Greek: Θορικός) was a city, and later a deme in the southern portion of ancient Attica, one of the twelve original settlements that were united in the synoikismos attributed to Theseus to form Archaic Athens. It was later a deme of the phyle of Acamantis. Near it are the mines of Laurion, where lead and silver was mined from Neolithic times, and worked in the industrial quarter of the settlement. There is a theatre dating from c. 525–480 BC. The modern site is Lavrio.

Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.

Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms. It is often associated with the minerals sphalerite, calcite and fluorite.

Lavreotiki (Greek: Λαυρεωτική) is a municipality at the southeasternnmost tip of the Attica peninsula in the Greek regional unit of East Attica. Its municipal seat is the town of Laurium.

It is historically important as a significant ancient mining district, most notably in the villages of Laurium and Thorikos on the southeastern seaboard during the 6th, 5th, and 4th centuries BCE. As such it financed the wealth of Athens and the emergence of the Athenian Empire through the slave-powered mining efforts for silver and lead, beginning with the discovery of 2 deep-vein mining efforts during the 480's. Prior to that development, which at Themistocles urging in 483 BC led to the expansion of the Athenian fleet to 200 ships, only surface-mining was deployed as a technique for harvesting silver. More than 250 ore washeries have been identified by archaeologists and geologists in the district.

Fiat money is a type of government-issued currency, authorized by government regulation to be legal tender. Typically, fiat currency is not backed by a precious metal, such as gold or silver, nor by any other tangible asset or commodity. Since the end of the Bretton Woods system in 1976 by the Jamaica Accords, all the major currencies in the world are fiat money.

Fiat money generally does not have intrinsic value and does not have use value. It has value only because the individuals who use it (as a unit of account or, in the case of currency, a medium of exchange) agree on its value. They trust that it will be accepted by merchants and other people as a means of payment for liabilities.

The Spanish dollar, originally known as the piece of eight (Spanish: real de a ocho, peso duro, peso fuerte or peso), and much later also dólar is a silver coin of approximately 38 mm (1.5 in) diameter worth eight Spanish reales. It was minted in the Spanish Empire following a monetary reform in 1497 with content 25.563 g (0.8219 ozt) fine silver. It was widely used as the first international currency because of its uniformity in standard and milling characteristics. Some countries countermarked the Spanish dollar so it could be used as their local currency.

Because the Spanish dollar was widely used in Europe, the Americas, and the Far East, it became the first world currency by the 16th century.

Bimetallism, also known as the bimetallic standard, is a monetary standard in which the value of the monetary unit is defined as equivalent to certain quantities of two metals, creating a fixed rate of exchange between them. In all known historical cases, the metals are gold and silver.

For scholarly purposes, "proper" bimetallism is sometimes distinguished as permitting that both gold and silver money are legal tender in unlimited amounts and that gold and silver may be taken to be coined by the government mints in unlimited quantities. This distinguishes it from "limping standard" bimetallism, where both gold and silver are legal tender but only one is freely coined (e.g. the monies of France, Germany, and the United States after 1873), and from "trade" bimetallism, where both metals are freely coined but only one is legal tender and the other is used as "trade money" (e.g. most monies in western Europe from the 13th to 18th centuries). Economists also distinguish legal bimetallism, where the law guarantees these conditions, and de facto bimetallism, where gold and silver coins circulate at a fixed rate.