Roman metallurgy

Prehistory in the Iberian peninsula begins with the arrival of the first Homo genus representatives from Africa, which may range from c. 1.5 million years (Ma) ago to c. 1.25 Ma ago, depending on the dating technique employed, so it is set at c. 1.3 Ma ago for convenience. The end of Iberian prehistory coincides with the first entrance of the Roman army into the peninsula, in 218 before Christ (BC), which led to the progressive dissolution of pre-Roman peoples in Roman culture. This end date is also conventional, since pre-roman writting systems can be traced as early as 5th century BC.

Several species of humans have intermittently occupied Great Britain for almost a million years. The earliest evidence of human occupation around 900,000 years ago is at Happisburgh on the Norfolk coast, with stone tools and footprints probably made by Homo antecessor. The oldest human fossils, around 500,000 years old, are of Homo heidelbergensis at Boxgrove in Sussex. Until this time Britain had been permanently connected to the Continent by a chalk ridge between South East England and northern France called the Weald-Artois Anticline, but during the Anglian Glaciation around 425,000 years ago a megaflood broke through the ridge, and Britain became an island when sea levels rose during the following Hoxnian interglacial.

Copper is a chemical element with the symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.

Gold is a chemical element with the symbol Au 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, as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver, 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.

Lead is a chemical element with the symbol Pb and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children.

A native metal is any metal that is found pure in its metallic form in nature. Metals that can be found as native deposits singly or in alloys include aluminium, antimony, arsenic, bismuth, cadmium, chromium, cobalt, indium, iron, manganese, molybdenum, nickel, niobium, rhenium, selenium, tantalum, tellurium, tin, titanium, tungsten, vanadium, and zinc, as well as the gold group and the platinum group. Among the alloys found in native state have been brass, bronze, pewter, German silver, osmiridium, electrum, white gold, silver-mercury amalgam, and gold-mercury amalgam.

Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals and sometimes non-metals, such as phosphorus, or metalloids such as arsenic or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as strength, ductility, or machinability.

Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid melts to become a liquid.

Cupellation is a refining process in metallurgy where ores or alloyed metals are treated under very high temperatures and have controlled operations to separate noble metals, like gold and silver, from base metals, like lead, copper, zinc, arsenic, antimony, or bismuth, present in the ore. The process is based on the principle that precious metals do not oxidise or react chemically, unlike base metals. When they are heated at high temperatures, the precious metals remain apart, and the others react, forming slags or other compounds.

Molding or moulding is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix. This itself may have been made using a pattern or model of the final object.

Iron is a chemical element with symbol Fe and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, just ahead of oxygen, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust, being mainly deposited by meteorites in its metallic state, with its ores also being found there.

Las Médulas is a historic gold-mining site near the town of Ponferrada in the comarca of El Bierzo. It was the most important gold mine, as well as the largest open-pit gold mine in the entire Roman Empire. Las Médulas Cultural Landscape is listed by UNESCO as a World Heritage Site. Advanced aerial surveys conducted in 2014 using LIDAR have confirmed the wide extent of the Roman-era works.

Ruina montium was allegedly an ancient Roman mining technique that draws on the principle of Pascal's barrel. Miners would excavate narrow cavities down into a mountain, whereby filling the cavities with water would cause pressures large enough to fragment thick rock walls. It was described by Pliny the Elder, who served as procurator in Spain.

Gaul was a region of Western Europe first clearly described by the Romans, encompassing present-day France, Belgium, the Netherlands, Luxembourg, and parts of Switzerland, Germany, and Northern Italy. It covered an area of 494,000 km2 (191,000 sq mi). According to Julius Caesar, who took control of the region on behalf of the Roman Republic, Gaul was divided into three parts: Gallia Celtica, Belgica, and Aquitania.

Dalmatia is a historical region on the eastern shore of the Adriatic Sea in Croatia, a narrow belt stretching from the island of Rab in the north to the Bay of Kotor in the south. The Dalmatian Hinterland ranges in width from fifty kilometres in the north, to just a few kilometres in the south; it is mostly covered by the rugged Dinaric Alps. Seventy-nine islands run parallel to the coast, the largest being Brač, Pag, and Hvar. The largest city is Split, followed by Zadar, Šibenik, and Dubrovnik.

Midian is a geographical place mentioned in the Hebrew Bible and Quran. William G. Dever states that biblical Midian was in the "northwest Arabian Peninsula, on the east shore of the Gulf of Aqaba on the Red Sea", an area which he notes was "never extensively settled until the 8th–7th century B.C."

Bactria, or Bactriana, was an ancient Iranian civilization in Central Asia centered on modern day Northern Afghanistan and including parts of southwestern Tajikistan and southeastern Uzbekistan.

Cyprus, officially the Republic of Cyprus, is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. It is geographically in Western Asia, but its cultural ties and geopolitics are overwhelmingly Southeastern European. Cyprus is the third-largest and third-most populous island in the Mediterranean. It is located north of Egypt, east of Greece, south of Turkey, and west of Lebanon and Syria. Its capital and largest city is Nicosia. The northeast portion of the island is de facto governed by the self-declared Turkish Republic of Northern Cyprus.

Aleppo is a city in Syria, which serves as the capital of the Aleppo Governorate, the most populous governorate of Syria. With an estimated population of 2,098,000 residents as of 2021, it is Syria's second-largest city and also one of the largest cities in the Levant region.

The Sinai Peninsula, or simply Sinai, is a peninsula in Egypt, and the only part of the country located in Asia. It is between the Mediterranean Sea to the north and the Red Sea to the south, and is a land bridge between Asia and Africa. Sinai has a land area of about 60,000 km2 (23,000 sq mi) and a population of approximately 600,000 people. Administratively, the vast majority of the area of the Sinai Peninsula is divided into two governorates: the South Sinai Governorate and the North Sinai Governorate. Three other governorates span the Suez Canal, crossing into African Egypt: Suez Governorate on the southern end of the Suez Canal, Ismailia Governorate in the center, and Port Said Governorate in the north.

Hallstatt is a small town in the district of Gmunden, in the Austrian state of Upper Austria. Situated between the southwestern shore of Hallstätter See and the steep slopes of the Dachstein massif, the town lies in the Salzkammergut region, on the national road linking Salzburg and Graz.

Lead is a chemical element with the symbol Pb and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children.

Cartagena is a Spanish city and a major naval station on the Mediterranean coast, south-eastern Iberia. As of January 2018, it has a population of 218,943 inhabitants, being the region's second-largest municipality and the country's sixth-largest non-provincial-capital city. The metropolitan area of Cartagena, known as Campo de Cartagena, has a population of 409,586 inhabitants.

Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid melts to become a liquid.

Molding or moulding is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix. This itself may have been made using a pattern or model of the final object.

Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various time setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods. Heavy equipment like machine tool beds, ships' propellers, etc. can be cast easily in the required size, rather than fabricating by joining several small pieces. Casting is a 7,000-year-old process. The oldest surviving casting is a copper frog from 3200 BC.

Electrum is a naturally occurring alloy of gold and silver, with trace amounts of copper and other metals. Its color ranges from pale to bright yellow, depending on the proportions of gold and silver. It has been produced artificially, and is also known as "green gold".

Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater. The open ocean has about 35 g (1.2 oz) of solids per liter of sea water, a salinity of 3.5%.

A metallurgical furnace, more commonly referred to as a furnace, is a device used to heat and melt metal ore to remove gangue, primarily in iron and steel production. The heat energy to fuel a furnace may be supplied directly by fuel combustion, by electricity such as the electric arc furnace, or through induction heating in induction furnaces. There are several different types of furnaces used in metallurgy to work with specific metal and ores.

Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.

A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy, such as nuclear energy.

Charcoal is a lightweight black carbon residue produced by strongly heating wood in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln, the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen. The material can also be heated in a closed retort. Modern "charcoal" briquettes used for outdoor cooking may contain many other additives, e.g. coal.

Arles is a coastal city and commune in the South of France, a subprefecture in the Bouches-du-Rhône department of the Provence-Alpes-Côte d'Azur region, in the former province of Provence.

The Janiculum, occasionally the Janiculan Hill, is a hill in western Rome, Italy. Although it is the second-tallest hill in the contemporary city of Rome, the Janiculum does not figure among the proverbial Seven Hills of Rome, being west of the Tiber and outside the boundaries of the ancient city.

Decimius Magnus Ausonius was a Roman poet and teacher of rhetoric from Burdigala in Aquitaine, modern Bordeaux, France. For a time he was tutor to the future emperor Gratian, who afterwards bestowed the consulship on him. His best-known poems are Mosella, a description of the river Moselle, and Ephemeris, an account of a typical day in his life. His many other verses show his concern for his family, friends, teachers, and circle of well-to-do acquaintances and his delight in the technical handling of meter.

South Wales is a loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the historic counties of Glamorgan and Monmouthshire, south Wales extends westwards to include Carmarthenshire and Pembrokeshire. In the western extent, from Swansea westwards, local people would probably recognise that they lived in both south Wales and west Wales. The Brecon Beacons National Park covers about a third of south Wales, containing Pen y Fan, the highest British mountain south of Cadair Idris in Snowdonia.

Georgius Agricola was a German Humanist scholar, mineralogist and metallurgist. Born in the small town of Glauchau, in the Electorate of Saxony of the Holy Roman Empire, he was broadly educated, but took a particular interest in the mining and refining of metals. For his groundbreaking work De Natura Fossilium published in 1546, he is generally referred to as the Father of Mineralogy.

The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It documents the story of human culture from its beginnings to the present. The British Museum was the first public national museum to cover all fields of knowledge.

Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold. It is also used in mining kaolin and coal.

Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below soil and sub-soil, which must be stripped away to discover the ore veins. A flood of water is very effective in moving soil as well as working the ore deposits when combined with other methods such as fire-setting.

The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going from hand production methods to machines; new chemical manufacturing and iron production processes; the increasing use of water power and steam power; the development of machine tools; and the rise of the mechanized factory system. Output greatly increased, and a result was an unprecedented rise in population and in the rate of population growth. The textile industry was the first to use modern production methods, and textiles became the dominant industry in terms of employment, value of output, and capital invested.

Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a type of fossil fuel, formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times. Many significant coal deposits are younger than this and originate from the Mesozoic and Cenozoic eras.

The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium and France. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than 970 kilometres (600 mi) long and 580 kilometres (360 mi) wide, covering 570,000 square kilometres (220,000 sq mi).

Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. It is typically hard but friable. Its quality is ranked higher than lignite and sub-bituminous coal, but lesser than anthracite. It is the most abundant rank of coal, with deposits found around the world, often in rocks of Carboniferous age. Bituminous coal is formed from sub-bituminous coal that is buried deeply enough to be heated to 85 °C (185 °F) or higher.

Populonia or Populonia Alta today is a frazione of the comune of Piombino. As of 2009 its population was 17. Populonia is especially noteworthy for its Etruscan remains, including one of the main necropolis in Italy, discovered by Isidoro Falchi.

Lead is a chemical element with the symbol Pb and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children.

The Early Middle Ages, sometimes controversially referred to as the Dark Ages, is typically regarded by historians as lasting from the late 5th or early 6th century through the 10th century. They marked the start of the Middle Ages of European history, following the decline of the Western Roman Empire, and preceding the High Middle Ages. The alternative term late antiquity, for the early part of the period, emphasizes elements of continuity with the Roman Empire, while Early Middle Ages is used to emphasize developments characteristic of the earlier medieval period.

The Abbasid Caliphate was the third caliphate to succeed the Islamic prophet Muhammad. It was founded by a dynasty descended from Muhammad's uncle, Abbas ibn Abd al-Muttalib, from whom the dynasty takes its name. They ruled as caliphs for most of the caliphate from their capital in Baghdad in modern-day Iraq, after having overthrown the Umayyad Caliphate in the Abbasid Revolution of 750 CE (132 AH). The Abbasid Caliphate first centered its government in Kufa, modern-day Iraq, but in 762 the caliph Al-Mansur founded the city of Baghdad, near the ancient Babylonian capital city of Babylon. Baghdad became the center of science, culture and invention in what became known as the Golden Age of Islam. This, in addition to housing several key academic institutions, including the House of Wisdom, as well as a multiethnic and multi-religious environment, garnered it a worldwide reputation as the "Center of Learning".

Gold is a chemical element with the symbol Au 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, as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver, 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.

Lusitania was an ancient Iberian Roman province located where modern Portugal and a portion of western Spain lie. It was named after the Lusitani or Lusitanian people.

Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in nonpolar organic solvents such as hexane, benzene and chloroform. Natural waxes of different types are produced by plants and animals and occur in petroleum.

Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2Si2O5(OH)4).

A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, and brick.

Mass production, also known as flow production or continuous production, is the production of substantial amounts of standardized products in a constant flow, including and especially on assembly lines. Together with job production and batch production, it is one of the three main production methods.

A fibula is a brooch or pin for fastening garments, typically at the right shoulder. The fibula developed in a variety of shapes, but all were based on the safety-pin principle. Unlike most modern brooches, fibulae were not only decorative; they originally served a practical function: to fasten clothing for both sexes, such as dresses and cloaks. In English, "fibula" is not a word used for modern jewellery, but by archaeologists, who also use "brooch", especially for types other than the ancient "safety pin" types, and for types from the British Isles.

Communication is usually defined as the transmission of information. The term can also refer to the message itself, or the field of inquiry studying these transmissions, also known as communication studies. There are some disagreements about the precise definition of communication - for example, whether unintentional or failed transmissions are also included and whether communication does not just transmit meaning but also create it. Models of communication aim to provide a simplified overview of its main components and their interaction. Many models include the idea that a source uses a coding system to express information in the form of a message. The source uses a channel to send the message to a receiver who has to decode it in order to understand its meaning. Channels are usually discussed in terms of the senses used to perceive the message, like hearing, sight, smell, touch, and taste.

Mining is the extraction of valuable geological materials from the Earth and other astronomical objects. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Ore must be a rock or mineral that contains valuable constituent, can be extracted or mined and sold for profit. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water.

An empire is a political unit made up of several territories and peoples, "usually created by conquest, and divided between a dominant center and subordinate peripheries". The center of the empire exercises political control over the peripheries. Within an empire, different populations have different sets of rights and are governed differently. Narrowly defined, an empire is a sovereign state whose head of state is an emperor; but not all states with aggregate territory under the rule of supreme authorities are called empires or ruled by an emperor; nor have all self-described empires been accepted as such by contemporaries and historians.

Indentured servitude is a form of labor in which a person is contracted to work without salary for a specific number of years. The contract, called an "indenture", may be entered "voluntarily" for purported eventual compensation or debt repayment, or it may be imposed as a judicial punishment. Historically, it has been used to pay for apprenticeships, typically when an apprentice agreed to work for free for a master tradesman to learn a trade. Later it was also used as a way for a person to pay the cost of transportation to colonies in the Americas.

Hadrian was Roman emperor from 117 to 138. He was born in Italica, a Roman municipium founded by Italic settlers in Hispania Baetica. He came from a branch of the gens Aelia that originated in the Picenean town of Hadria, the Aeli Hadriani. His father was of senatorial rank and was a first cousin of Emperor Trajan. Hadrian married Trajan's grand-niece Vibia Sabina early in his career before Trajan became emperor and possibly at the behest of Trajan's wife Pompeia Plotina. Plotina and Trajan's close friend and adviser Lucius Licinius Sura were well disposed towards Hadrian. When Trajan died, his widow claimed that he had nominated Hadrian as emperor immediately before his death.

Graffiti is art that is written, painted or drawn on a wall or other surface, usually without permission and within public view. Graffiti ranges from simple written words to elaborate wall paintings, and has existed since ancient times, with examples dating back to ancient Egypt, ancient Greece, and the Roman Empire.

Citizenship in ancient Rome was a privileged political and legal status afforded to free individuals with respect to laws, property, and governance. Citizenship in Ancient Rome was complex and based upon many different laws, traditions, and cultural practices. There existed several different types of citizenship, determined by one's gender, class, and political affiliations, and the exact duties or expectations of a citizen varied throughout the history of the Roman Empire.

An economy is an area of the production, distribution and trade, as well as consumption of goods and services. In general, it is defined as a social domain that emphasize the practices, discourses, and material expressions associated with the production, use, and management of scarce resources. A given economy is a set of processes that involves its culture, values, education, technological evolution, history, social organization, political structure, legal systems, and natural resources as main factors. These factors give context, content, and set the conditions and parameters in which an economy functions. In other words, the economic domain is a social domain of interrelated human practices and transactions that does not stand alone.

India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area and the second-most populous country. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west; China, Nepal, and Bhutan to the north; and Bangladesh and Myanmar to the east. In the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives; its Andaman and Nicobar Islands share a maritime border with Thailand, Myanmar, and Indonesia.

China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. With an area of approximately 9.6 million square kilometres (3,700,000 sq mi), it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two special administrative regions. The national capital is Beijing, and the most populous city and largest financial center is Shanghai.

A gemstone is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks and occasionally organic materials that are not minerals are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity and notoriety are other characteristics that lend value to gemstones.

Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance of silk is due to the triangular prism-like structure of the silk fibre, which allows silk cloth to refract incoming light at different angles, thus producing different colors.

Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the science and the technology of metals; that is, the way in which science is applied to the production of metals, and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking. Metalworking relies on metallurgy in a similar manner to how medicine relies on medical science for technical advancement. A specialist practitioner of metallurgy is known as a metallurgist.