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Name of the Spanish language

The Spanish language has two names: español (Spanish) and castellano (Castilian). Spanish speakers from different countries or backgrounds can show a preference for one term or the other, or use them indiscriminately, but political issues or common usage might lead speakers to prefer one term over the other. This article identifies the differences between those terms, the countries or backgrounds that show a preference for one or the other, and the implications the choice of words might have for a native Spanish speaker.

Formally speaking, the national language of Spain, the official Spanish language, is the Castilian language (as opposed to the regional languages of Spain, such as Galician, Catalan, Asturleonese, and Basque). As such both names, español and castellano, have distinct and independent meanings that may be required for clarity in some specific contexts. Generally speaking, though, both terms can be used to refer to the (national) Spanish language as a whole, with a preference for one over the other that depends on the context or the speaker's origin. Castellano (as well as Castilian in English) has another, more restricted, meaning, relating either to the old Romance language spoken in the Kingdom of Castile in the Middle Ages, predecessor of the modern Spanish language, or to the variety of Spanish nowadays spoken in the historical region of Castile, in central Spain.

History of the terms
Originally Castilian (castellano) referred to the language of the Kingdom of Castile, one of several northern kingdoms that spread across the Iberian Peninsula through the Middle Ages, from about the 8th to the 15th centuries. Traditionally the first recorded examples of written Castilian/Spanish are considered to be the Glosas Emilianenses, a number of isolated words added to a Latin text as an aid to the reader, dated to the eleventh century. Soon after that there begin to appear discursive texts in Castilian, such as the Cantar de Mio Cid. This early Romance language was derived from Latin and evolved into modern Spanish.

However, the term Spanish (español) is a more recent term that first referred to Spain as a country, and then to the predominant language spoken in that country. Spain as a truly unified nation appeared centuries later than the language and the Kingdom of Castile; in fact, it was only in the late 15th century that the personal union between the Crowns of Castile and Aragon unified Spain. The actual legal unification date is disputed, but commonly agreed to have occurred not earlier than the eighteenth century at the end of the War of the Spanish Succession. Only then did the Castilian language begin to be commonly called Spanish.

In 1492, the arrival of Christopher Columbus on a Castilian-paid expedition paved the way for the Spanish colonization of the Americas. As a result of this process, most countries in South America now speak the same language as Castile. Until about the eighteenth century, the Kingdom of Castile, and not Spain as a whole, was the colonizing power, and the language used was called castellano. Thus, some Latin American countries formerly under Spanish rule have retained the custom of calling it castellano, while others eventually switched to calling it español, with many different factors influencing the final choice.

In English, the term Spanish relates both to the language and to the nation. The noun used for a person from Spain is Spaniard, with the collective noun the Spanish. The term Castilian is much less widespread amongst English speakers than the term Spanish.

Español
Two main hypotheses have been proposed for the origin of the word español: one based on dissimilation in Old Spanish españón (from a presumed Vulgar Latin *hispaniōne), and the other on an Occitan term derived from a presumed Vulgar Latin *hispaniolus. Both Latin ancestor words are based on the place name Hispania (which evolved into España by regular sound changes); and both are marked with an asterisk to indicate that they are reconstructed, not directly attested.

The dissimilation hypothesis, advanced by Ramón Menéndez Pidal, presumes that Latin Hispania was lengthened by the derivational suffix -ōne (which survives in other ethnonyms such as bretón, borgoñón, sajón, and lapón). The Old Spanish form españon is documented in works of the 13th and 14th centuries. It is suggested that the final /n/ of this form changed to /l/ by dissimilation from the previous nasal consonant, ñ. This sporadic sound change is observed in some other words: Menéndez Pidal cites Barcelona (from Barcinone) and delante (from de in ante); Lathrop adds ingle (from ing[ui]ne) and sangre (from sang[ui]ne).

According to the Occitan scenario, advanced by Rafael Lapesa, the Spanish borrowed the Occitan name for themselves, which was the name España plus the diminutive suffix -ol, from the Latin -olus. The Occitan influence is inferred because in Castilian the same Latin suffix would have produced *españuelo rather than español. Lapesa counters the dissimilation hypothesis by citing other words with -ñón in which dissimilation did not take place: cañón, borgoñón, riñón, etc. (However, the suffix could have been restored analogically in these, or they were formed after the dissimilation took place.) Penny, in discussing loans from French and Occitan, calls this "the most remarkable loan of all, español 'Spanish', replacing native españón."

The name Hispania was applied to the Iberian Peninsula by the Romans when they discovered and later subjugated it. One theory about this name is that it comes from Canaanite אי שפנים (ʾî šəpānîm), meaning 'island of hyraxes', named by Canaanite-speaking Phoenicians who mistook Spain's large rabbit population for hyraxes. Several other theories about the name have been advanced as well (see Hispania).

The Romans called the inhabitants of Hispania hispani (singular: hispanus), and the relevant adjective was hispanicus. These terms, had they undergone regular sound change into Castilian, would have developed into España, *espanos (singular: *espano) and *espánego or *espango—but in reality, only the first term exists in modern Castilian.

As the branches of Vulgar Latin began to evolve into separate Romance languages, the term that would evolve into español began to be used to refer to these derivative languages (especially as opposed to the Arabic and Hebrew of the Moorish and Jewish inhabitants of Iberia). It was at first a general term that embraced the various dialects of Iberian Romance spoken in the area, including the forebears of modern Portuguese, Galician, Castilian and Catalan. However, with the rise of Castile as a power, and its absorption of all surrounding regions into an ever-growing empire that eventually spread to the New World, the term España was eventually equated with the peninsular territories ruled by the Crown. With this, the break with the Roman concept of Hispania was complete, and the term acquired its modern meaning of 'all of Iberia except for Portugal and Andorra'. Similarly, español came to be used to refer to the common language of this new country: Castilian.

The terms España and español spread to other languages. The English name Spain is from the French Espagne. Spanish is Spain plus the English suffix -ish. The term continues evolving as other languages adapt these words to form their own name for Spain—for example, Japanese スペイン語 (Supein-go), 'Spanish language', and スペイン人 (Supein-jin), 'Spaniard', derive from the Japanese word for Spain, スペイン (Supein), which, in turn, derives from English Spain. In Chinese, the word is taken directly from Spanish (or perhaps even Latin) rather than English: 西班牙 ( Pinyin phonetic symbols: xībānyá) for Spain and 西班牙语 ( Pinyin: xībānyá yǔ), or the abbreviation 西語 ( Pinyin: xī yǔ) for the Spanish language. The Arabic إسبانية (isbāniya) for Spain derives directly from the word Hispania (noting that the absence of "p" in the Arabic alphabet makes it a "b").

Castellano
Castilla ("Castile" in English) is commonly thought to mean 'Castle-land'. The word is derived from Latin castella, the plural of castellum, which, in turn, is a diminutive form of castrum' 'fortress, castle'. Through most of the Middle Ages the word was spelled Castiella, a form that survives in Leonese today. (Modern Spanish has transformed all words ending in -iello, -iella into illo, -illa.) The adjective derived from Castilla is castellano. 'Castellano also means 'castellan', i.e. a castle master. There is a comic scene based on the play on words Castilian/castellan in the novel Don Quixote (Chapter 2).

The region was thus named because it was a frontier land controlled from a series of fortified castles. It shared borders with rival Moorish Iberia (to the south) and the Christian kingdoms of Leon (to the west) and Navarre and Aragon (to the east).

In Guatemala, although Spanish is the official language, the Maya peoples, descendants of the original inhabitants of the region, call it la castilla, keeping the original name from colonial times. Mayans speak at least 22 different Mayan languages and dialects, including Mam, Pocomam, Kaqchikel, Tz’utujil, Q’eqchi’, and Kʼicheʼ.

"Cristiano"
During the presence of Moors in Hispania, Spanish was sometimes given the name cristiano ("Christian") to distinguish it from the Arabic and Hebrew languages - although the language spoken by Christians under Islamic rule was Mozarabic (of which Aragonese is actually the closest living language). This term is still used occasionally today to refer to the language, in a jocular tone. The expression Háblame en cristiano "talk to me in Christian", said to people not speaking Spanish at the moment, is used in opposition of the other languages of Spain, (Catalan, Galician, Basque, as well as others such as Asturian or Aragonese), to the chagrin of the speakers of these languages. The phrase is not used in the Americas. "Háblame en cristiano" is also a phrase used to ask for clarification in a conversation, when the topic of the discussion is not clear or is vaguely hinted at by one of the speakers.

"Language of Cervantes"
The term lengua de Cervantes as an epithet for the Spanish language began to be used early in the 19th century. Mariano José de Larra uses the expression in his essay Literatura, first published in 1823. In 1829 it appears in Una cuestión de derecho, by Manuel Sivela. Soon after that it appears in an anonymous article in the Gaceta de Madrid. The poet Nicasio Camilo Jover, in his poem Miguel de Cervantes, states directly Y la lengua del pueblo castellano / Hoy se llama la lengua de Cervantes. Spanish is called el idioma de Cervantes in a book published in 1830, and in another one published in 1838.

Occasionally the term refers to the language of Spanish Golden Age literature generally, rather than simply to that of Cervantes.

"The language of Cervantes" in English—as a term for the Spanish language generally—comes into use in the 1840s. Examples appear in Janin (1841) and Campbell (1849).

While quotations and expressions from Cervantes' work are still in use, the actual language and spelling that Cervantes used can sound archaic to modern readers. Modern editions may modernize it to appeal the current public.

"Román paladino"
The poet Gonzalo de Berceo, writing in the 13th century, used the phrase román paladino to mean simple, straightforward language, the language spoken by the common people, as opposed to Latin. In the famous passage from his Vida de Santo Domingo de Silos, Berceo says Quiero fer una prosa en roman paladino, / en cual suele el pueblo fablar con so vezino; / ca non so tan letrado por fer otro latino. / Bien valdra, como creo, un vaso de bon vino ("I want to write verse [sic] in clear vernacular, in which the townsfolk speak to their neighbor; for I'm not so learned as to make another in Latin. It will be worth, I think, a glass of good wine"). Roman—and, more frequently romanz (and later romance)—was used in medieval Spanish as a synonym of castellano, i.e. the language now commonly called Old Spanish. And paladino meant—in Berceo's time the same as it does today—"public, clear, obvious". (Old Spanish paladino existed alongside its learned cognate palatino, which usually referred to the Palatine Hill of Rome. Both words are derived ultimately from Latin palatīnum "of the palace", with influence from Latin palam "openly".) Today román paladino is a high-sounding epithet for clear, straightforward Spanish. Recently it has been popularized in public speeches by Spain's Prime Minister Mariano Rajoy, who has used it frequently as an equivalent for "I will clearly state..."

Royal Spanish Academy
In Spain, the Royal Spanish Academy is a normative body that rules on the orthography and general usage rules of the language. The Academy has used castellano since the 18th century, but since 1923, its dictionary and grammar are de la lengua española ("of the Spanish language"). The Academy's usage of one term is not necessarily a condemnation of the other.

There are many other academies (grouped under the Association of Spanish Language Academies) that may or may not have an official normative recognition but nevertheless cooperate in the creation of the Diccionario panhispánico de dudas (a compendium of corrected typical mistakes and doubts). The dictionary, whose production was agreed upon by the 22 different Spanish Language Academies, says:

"Para designar la lengua común de España y de muchas naciones de América, y que también se habla como propia en otras partes del mundo, son válidos los términos castellano y español. La polémica sobre cuál de estas denominaciones resulta más apropiada está hoy superada. [...] Aun siendo sinónimo de español, resulta preferible reservar el término castellano para referirse al dialecto románico nacido en el Reino de Castilla durante la Edad Media, o al dialecto del español que se habla actualmente en esa región."

"When naming the common language of Spain and of many nations of America, which is also spoken as a first language in other parts of the world, the terms Castilian and Spanish are [both] valid. The debate over which of these designations is more appropriate is presently settled. [...] Although it is a synonym of Spanish, it is preferable to reserve the term Castilian to refer to the Romance language arising in the Kingdom of Castile during the Middle Ages, or to the dialect of Spanish currently spoken in that region."

Thus, even if both terms are allowed in Spanish, the use of español is recommended for the language as a whole. However, popular choice of terms is not so clear, with other factors, such as customs or geographical location, being factors.

Usage in Spain
Spaniards tend to call the language español (Spanish) to contrast it to languages of other states, such as in a list with French (francés), German (alemán), etc. Castellano (Castilian) by contrast, is more often used when contrasting the language with other regional languages of Spain: official languages like Basque, Catalan and Galician or unofficial ones like Aragonese, Asturian, Extremaduran and Leonese. The Spanish Constitution of 1978 uses the term el castellano to define the official language of the whole State, opposed to las demás lenguas españolas (the other Spanish languages). Article 3 reads in part:

"El castellano es la lengua española oficial del Estado. Todos los españoles tienen el deber de conocerla y el derecho a usarla. Las demás lenguas españolas serán también oficiales en las respectivas Comunidades Autónomas..."

"Castilian is the official Spanish language of the State. All Spaniards have the duty to know it and the right to use it. The other Spanish languages as well shall be official in their respective Autonomous Communities..."

This choice of words, however, varies depending on many factors, including the origin of the speaker or some political nuances.

Bilingual and multilingual regions of Spain
In the regions where regional languages are spoken, there is a daily need to make the contrast between the national language and the regional language and so the national language is most often referred to as Castilian, particularly in the regional languages themselves (for example, espanyol is virtually never used to refer to the language in Catalan: castellà is used instead; in Basque, the name of the language is gaztelania or gaztelera, rather than espainiera; and in Galician, the most commonly used term is "castelán" rather than "español"). That is often mirrored by educated English-speakers to refer to the linguistic situation in Spain.

For some, this use of the term castellano is a political or cultural statement that Spanish is only the language of Castile, perhaps also of some areas that Castile colonised, but not the language of their region, which they consider the only legitimate language to be the regional one: Catalan, Basque, Galician etc. That stance is common in regionalist circles.

Conversely, some nationalist circles prefer the term español because they perceive their ethnic community to be distinct from that of Spain and therefore do not object to the language of Spain being called Spanish. In Basque-speaking regions, whose language is not of Romance origin (Basque is considered by many scholars to be a language isolate), some Basque speakers also use the term erdara or erdera (foreign) specifically for Spanish, since for them, it is the prevalent foreign language, just as in the French Basque Country, "French language" is the usual meaning of erdara; in fact, erdara is another language, different from Basque.

Monolingual regions of Spain
In monolingual regions, the implications are a little different. In such regions, there is no identity implication, but still, they must choose one of the two terms. Castilians usually use the term el español, legitimately presenting it as the national language. However, they also frequently call it el castellano, either to assert their ownership or to distinguish it from the regional languages.

Monolingual regions outside of Castile include mainly Andalusia but also other regions where the regional languages are not developed enough to be widely spoken by the majority of the population, such as Extremadura, Cantabria or Aragon. There, español may be used, as in Castile, to stress the national nature of the language but with a slightly different nuance: they are accepting another region's historical language as their own.

Concept of a standard
The term castellano is occasionally used to imply more of a standard form than español does. For example, if someone mispronounces a word, they might be told ¡Habla castellano!, i.e. 'Speak Castilian!', 'Speak properly!'. However, that nuance is not to be exaggerated, as it is perfectly possible that the term español or even, jocularly, cristiano ('Christian') could be used instead. Moreover, the term castellano is also commonly and correctly used to refer to dialects of Spanish, which deviate dramatically from the standard.

Usage and implications in former colonies
Both names are commonly used in parts of the world colonized by Spanish speakers, such as Latin America and the Canary Islands. As in Spain, the implications are complex. The most common term used in Latin America is español, generally considered to be a neutral term simply reflecting the country that the language came from. For people who use that term, castellano may possibly imply greater correctness, as it sometimes does in Spain, or it may merely be an alien term, referring to a region in a far-off country. The residents of Canary Islands usually call their language español, while Canary Islands is politically part of Spain. This is because Canary Islands are miles away from mainland Spain; in all areas of Spain, Canary Islands is the only area in Spain wherein the language is only called español and not castellano.

However, some Latin Americans prefer the term castellano, especially in Argentina, Chile, and Peru. One reason for this is that many early Argentine settlers were Galician, for whom castellano had long been associated with the Spanish state in addition to Castile. Along with Basques or Catalans, Galicians might perceive the term español as imperialistic and misrepresenting the language of Castile as the language of Spain.

In Chile, the term castellano has historically been popular mainly because this was the term introduced by the Spanish themselves during colonial times, and continued to be the more common term used by Chileans until the 1970s. With the widespread introduction of español to refer to the Spanish language via TV shows and cultural exchanges from Mexico, the United States, Spanish Caribbean, and Central America, this has become the more dominant name for the language, especially among younger generations and the middle to upper classes.

Peruvians often prefer the term castellano for similar reasons to avoid the linkage between español and España. The Governorate of New Castile (Gobernación de Nueva Castilla) was established in Lima, Peru in 1528, and Peruvian history classes still emphasize the Castilian origin of the first conquerors and settlers. That tendency often manifests itself in a preference for films dubbed into Latin American Spanish, which often take longer to reach the market, over those in Español (Peninsular Spanish characterized by the use of vosotros), which tend to be found in pirated "cam" versions of films. Using español to refer to Peninsular Spanish is exactly the opposite of how English-speakers use the two terms, which can create some confusion.

Castellano may also be used to refer to the dialect of Spanish spoken in Castile, and español would generally refer to Standard Spanish. In practice, usage tends to be a matter of local custom rather than reflecting any philosophical or political position. However, the fact that Castile is now a region subsumed within modern Spain has been the decisive factor in the preferential usage of español in an international context.

Countries whose constitutions use the term castellano

 * Bolivia: The amendment of 1994 mentions castellano in passing; schools use castellano, but español is still frequent in common speech.
 * Colombia: The Colombian Constitution of 1991 uses the term castellano to define the official language of the country: "El castellano es el idioma oficial de Colombia". However, español is the most used term in common speech.
 * Ecuador
 * Paraguay
 * Peru: The Peruvian Constitution of 1993 uses the term castellano to define the official language of the country. However, español is the most used term in common speech.
 * Philippines: The first two constitutions of the Philippines specify castellano, both in Spanish and Filipino (Kastilà), and the official Filipino version of the current 1987 Constitution uses Kastilà (castellano) when referring to the language. However, the term español (Espanyól) is also encountered in common speech and writing, and both terms are interchangeable in Philippine Spanish and other languages of the Philippines.
 * Spain: Castilian (castellano) is the official language of the State. All Spaniards have the duty to know it and the right to use it. Other Spanish languages (languages of Spain) shall be official in the respective autonomous communities, according to their Statutes of Autonomy.
 * Venezuela

Countries whose constitutions use the term español

 * Costa Rica
 * Equatorial Guinea
 * Guatemala
 * Honduras
 * Nicaragua
 * Panama

Countries whose constitutions do not mention any of the terms

 * Argentina
 * Chile
 * Cuba
 * Dominican Republic
 * Mexico
 * Uruguay

Usage and misconceptions abroad
Some philologists use "Castilian" only for the language spoken in Castile during the Middle Ages and state that it is preferable to use "Spanish" for its modern form. The dialect of Spanish spoken in northern parts of modern Castile may also be called "Castilian." It differs from those of other regions of Spain (Andalusia for example); the Castilian dialect is conventionally considered in Spain to be the same as Standard Spanish.

Another use of Castilian in English is to distinguish between the Standard Spanish of the Iberian Peninsula and regional dialects. As noted above, the distinction is made to some extent in Spanish but not as far as some English-speakers go; for example, websites with language selection screens give the choice between Castilian Spanish and Latin American Spanish, among other languages.

In the Americas, where Spanish is the native language of 20 countries, usage of castellano and español is sometimes reversed to refer to another nation. For example, a Peruvian talking about a Uruguayan might say, Yo hablo en español peruano, él habla en español uruguayo, pero los dos hablamos castellano ("I speak Peruvian Spanish, he speaks Uruguayan Spanish, but we both speak Castilian"). That usage comes from the historical association of español with the language that was brought to the Americas by conquistadores and was later transformed in each nation through daily usage, with castellano as the basis for all variants.

title: Name of the Spanish language


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Copper

Copper is a chemical element; it has 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.

Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from c. 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, c. 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 3500 BC.

Commonly encountered compounds are copper(II) salts, which often impart blue or green colors to such minerals as azurite, malachite, and turquoise, and have been used widely and historically as pigments.

Copper used in buildings, usually for roofing, oxidizes to form a green patina of compounds called verdigris. Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents, fungicides, and wood preservatives.

Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found mainly in the liver, muscle, and bone. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.

Etymology
In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes cyprium (metal of Cyprus), later corrupted to cuprum (Latin). Coper (Old English) and copper were derived from this, the later spelling first used around 1530.

Physical

Copper, silver, and gold are in group 11 of the periodic table; these three metals have one s-orbital electron on top of a filled d-electron shell and are characterized by high ductility, and electrical and thermal conductivity. The filled d-shells in these elements contribute little to interatomic interactions, which are dominated by the s-electrons through metallic bonds. Unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper. At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms.

The softness of copper partly explains its high electrical conductivity ($59.6 S/m$) and high thermal conductivity, second highest (second only to silver) among pure metals at room temperature. This is because the resistivity to electron transport in metals at room temperature originates primarily from scattering of electrons on thermal vibrations of the lattice, which are relatively weak in a soft metal. The maximum possible current density of copper in open air is approximately $3.1 A/m^{2}$, above which it begins to heat excessively.

Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air. This is due to the low plasma frequency of the metal, which lies in the red part of the visible spectrum, causing it to absorb the higher-frequency green and blue colors.

As with other metals, if copper is put in contact with another metal in the presence of an electrolyte, galvanic corrosion will occur.

Chemical
Copper does not react with water, but it does slowly react with atmospheric oxygen to form a layer of brown-black copper oxide which, unlike the rust that forms on iron in moist air, protects the underlying metal from further corrosion (passivation). A green layer of verdigris (copper carbonate) can often be seen on old copper structures, such as the roofing of many older buildings and the Statue of Liberty. Copper tarnishes when exposed to some sulfur compounds, with which it reacts to form various copper sulfides.

Isotopes
There are 29 isotopes of copper. 63Copper and 65Copper are stable, with 63Copper comprising approximately 69% of naturally occurring copper; both have a spin of $3/2$. The other isotopes are radioactive, with the most stable being 67Copper with a half-life of 61.83 hours. Seven metastable isomers have been characterized; 68mCopper is the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by β−, whereas those with a mass number below 64 decay by β+. [[Copper|64Copper]], which has a half-life of 12.7 hours, decays both ways.

62Copper and 64Copper have significant applications. 62Copper is used in 62CopperCu-PTSM as a radioactive tracer for positron emission tomography.

Occurrence
Copper is produced in massive stars and is present in the Earth's crust in a proportion of about 50 parts per million (ppm). In nature, copper occurs in a variety of minerals, including native copper, copper sulfides such as chalcopyrite, bornite, digenite, covellite, and chalcocite, copper sulfosalts such as tetrahedite-tennantite, and enargite, copper carbonates such as azurite and malachite, and as copper(I) or copper(II) oxides such as cuprite and tenorite, respectively. The largest mass of elemental copper discovered weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal, with the largest single crystal ever described measuring 4.4 × 3.2 × 3.2 cm. Copper is the 25th most abundant element in Earth's crust, representing 50 ppm compared with 75 ppm for zinc, and 14 ppm for lead.

Typical background concentrations of copper do not exceed $1 ng/m3$ in the atmosphere; $150 mg/kg$ in soil; $30 mg/kg$ in vegetation; 2 μg/L in freshwater and $0.5 μg/L$ in seawater.

Production

Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Sites include Chuquicamata, in Chile, Bingham Canyon Mine, in Utah, United States, and El Chino Mine, in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top producer of copper with at least one-third of the world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage. An alternative source of copper for collection currently being researched are polymetallic nodules, which are located at the depths of the Pacific Ocean approximately 3000–6500 meters below sea level. These nodules contain other valuable metals such as cobalt and nickel.

Reserves and prices
Copper has been in use for at least 10,000 years, but more than 95% of all copper ever mined and smelted has been extracted since 1900. As with many natural resources, the total amount of copper on Earth is vast, with around 1014 tons in the top kilometer of Earth's crust, which is about 5 million years' worth at the current rate of extraction. However, only a tiny fraction of these reserves is economically viable with present-day prices and technologies. Estimates of copper reserves available for mining vary from 25 to 60 years, depending on core assumptions such as the growth rate. Recycling is a major source of copper in the modern world.

The price of copper is volatile. After a peak in 2022 the price unexpectedly fell.

Methods
The great majority of copper ores are sulfides. Common ores are the sulfides chalcopyrite (CuFeS2), bornite (Cu5FeS4) and, to a lesser extent, covellite (CuS) and chalcocite (Cu2S). These ores occur at the level of <1% Cu. Concentration of the ore is required, which begins with comminution followed by froth flotation. The remaining concentrate is the smelted, which can be described with two simplified equations:
 * 2 Cu2S + 3 O2 → 2 Cu2O + 2 SO2

Cuprous oxide reacts with cuprous sulfide to convert to blister copper upon heating
 * 2 Cu2O + Cu2S → 6 Cu + 2 SO2

This roasting gives matte copper, roughly 50% Cu by weight, which is purified by electrolysis. Depending on the ore, sometimes other metals are obtained during the electrolysis including platinum and gold.

Aside from sulfides, another family of ores are oxides. Approximately 15% of the world's copper supply derives from these oxides. The beneficiation process for oxides involves extraction with sulfuric acid solutions followed by electrolysis. In parallel with the above method for "concentrated" sulfide and oxide ores, copper is recovered from mine tailings and heaps. A variety of methods are used including leaching with sulfuric acid, ammonia, ferric chloride. Biological methods are also used.

A significant source of copper is from recycling. Recycling is facilitated because copper is usually deployed in its metallic state. In 2001, a typical automobile contained 20–30 kg of copper. Recycling usually begins with some melting process using a blast furnace.

A potential source of copper is polymetallic nodules, which have an estimated concentration 1.3%.

Recycling
Like aluminium, copper is recyclable without any loss of quality, both from raw state and from manufactured products. In volume, copper is the third most recycled metal after iron and aluminium. An estimated 80% of all copper ever mined is still in use today. According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of copper in use in society is 35–55 kg. Much of this is in more-developed countries (140–300 kg per capita) rather than less-developed countries (30–40 kg per capita).

The process of recycling copper is roughly the same as is used to extract copper but requires fewer steps. High-purity scrap copper is melted in a furnace and then reduced and cast into billets and ingots; lower-purity scrap is refined by electroplating in a bath of sulfuric acid.

Environmental impacts
The environmental cost of copper mining was estimated at 3.7 kg CO2eq per kg of copper in 2019. Codelco, a major producer in Chile, reported that in 2020 the company emitted 2.8t CO2eq per ton (2.8 kg CO2eq per kg) of fine copper. Greenhouse gas emissions primarily arise from electricity consumed by the company, especially when sourced from fossil fuels, and from engines required for copper extraction and refinement. Companies that mine land often mismanage waste, rendering the area sterile for life. Additionally, nearby rivers and forests are also negatively impacted. The Philippines is an example of a region where land is overexploited by mining companies.

Copper mining waste in Valea Şesei, Romania, has significantly altered nearby water properties. The water in the affected areas is highly acidic, with a pH range of 2.1–4.9, and shows elevated electrical conductivity levels between 280 and 1561 mS/cm. These changes in water chemistry make the environment inhospitable for fish, essentially rendering the water uninhabitable for aquatic life.

Alloys

Numerous copper alloys have been formulated, many with important uses. Brass is an alloy of copper and zinc. Bronze usually refers to copper-tin alloys, but can refer to any alloy of copper such as aluminium bronze. Copper is one of the most important constituents of silver and karat gold solders used in the jewelry industry, modifying the color, hardness and melting point of the resulting alloys. Some lead-free solders consist of tin alloyed with a small proportion of copper and other metals.

The alloy of copper and nickel, called cupronickel, is used in low-denomination coins, often for the outer cladding. The US five-cent coin (currently called a nickel) consists of 75% copper and 25% nickel in homogeneous composition. Prior to the introduction of cupronickel, which was widely adopted by countries in the latter half of the 20th century, alloys of copper and silver were also used, with the United States using an alloy of 90% silver and 10% copper until 1965, when circulating silver was removed from all coins with the exception of the half dollar—these were debased to an alloy of 40% silver and 60% copper between 1965 and 1970. The alloy of 90% copper and 10% nickel, remarkable for its resistance to corrosion, is used for various objects exposed to seawater, though it is vulnerable to the sulfides sometimes found in polluted harbors and estuaries. Alloys of copper with aluminium (about 7%) have a golden color and are used in decorations. Shakudō is a Japanese decorative alloy of copper containing a low percentage of gold, typically 4–10%, that can be patinated to a dark blue or black color.

Compounds

Copper forms a rich variety of compounds, usually with oxidation states +1 and +2, which are often called cuprous and cupric, respectively. Copper compounds promote or catalyse numerous chemical and biological processes.

Binary compounds
As with other elements, the simplest compounds of copper are binary compounds, i.e. those containing only two elements, the principal examples being oxides, sulfides, and halides. Both cuprous and cupric oxides are known. Among the numerous copper sulfides, important examples include copper(I) sulfide (Cu2S) and copper monosulfide (CuS).

Cuprous halides with fluorine, chlorine, bromine, and iodine are known, as are cupric halides with fluorine, chlorine, and bromine. Attempts to prepare copper(II) iodide yield only copper(I) iodide and iodine.
 * 2 Cu2+ + 4 I− → 2 CuI + I2

Coordination chemistry
Copper forms coordination complexes with ligands. In aqueous solution, copper(II) exists as. This complex exhibits the fastest water exchange rate (speed of water ligands attaching and detaching) for any transition metal aquo complex. Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper(II) hydroxide. A simplified equation is:
 * Cu2+ + 2 OH− → Cu(OH)2

Aqueous ammonia results in the same precipitate. Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper(II):
 * + 4 NH3 → + 2 H2O + 2 OH−

Many other oxyanions form complexes; these include copper(II) acetate, copper(II) nitrate, and copper(II) carbonate. Copper(II) sulfate forms a blue crystalline pentahydrate, the most familiar copper compound in the laboratory. It is used in a fungicide called the Bordeaux mixture.

Polyols, compounds containing more than one alcohol functional group, generally interact with cupric salts. For example, copper salts are used to test for reducing sugars. Specifically, using Benedict's reagent and Fehling's solution the presence of the sugar is signaled by a color change from blue Cu(II) to reddish copper(I) oxide. Schweizer's reagent and related complexes with ethylenediamine and other amines dissolve cellulose. Amino acids such as cystine form very stable chelate complexes with copper(II)  including in the form of metal-organic biohybrids (MOBs). Many wet-chemical tests for copper ions exist, one involving potassium ferricyanide, which gives a red-brown precipitate with copper(II) salts.

Organocopper chemistry
Compounds that contain a carbon-copper bond are known as organocopper compounds. They are very reactive towards oxygen to form copper(I) oxide and have many uses in chemistry. They are synthesized by treating copper(I) compounds with Grignard reagents, terminal alkynes or organolithium reagents; in particular, the last reaction described produces a Gilman reagent. These can undergo substitution with alkyl halides to form coupling products; as such, they are important in the field of organic synthesis. Copper(I) acetylide is highly shock-sensitive but is an intermediate in reactions such as the Cadiot–Chodkiewicz coupling and the Sonogashira coupling. Conjugate addition to enones and carbocupration of alkynes can also be achieved with organocopper compounds. Copper(I) forms a variety of weak complexes with alkenes and carbon monoxide, especially in the presence of amine ligands.

Copper(III) and copper(IV)
Copper(III) is most often found in oxides. A simple example is potassium cuprate, KCuO2, a blue-black solid. The most extensively studied copper(III) compounds are the cuprate superconductors. Yttrium barium copper oxide (YBa2Cu3O7) consists of both Cu(II) and Cu(III) centres. Like oxide, fluoride is a highly basic anion and is known to stabilize metal ions in high oxidation states. Both copper(III) and even copper(IV) fluorides are known, K3CuF6 and Cs2CuF6, respectively.

Some copper proteins form oxo complexes, which, in extensively studied synthetic analog systems, feature copper(III). With tetrapeptides, purple-colored copper(III) complexes are stabilized by the deprotonated amide ligands.

Complexes of copper(III) are also found as intermediates in reactions of organocopper compounds, for example in the Kharasch–Sosnovsky reaction.

History
A timeline of copper illustrates how this metal has advanced human civilization for the past 11,000 years.

Copper Age
Copper occurs naturally as native metallic copper and was known to some of the oldest civilizations on record. The history of copper use dates to 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. Evidence suggests that gold and meteoric iron (but not smelted iron) were the only metals used by humans before copper. The history of copper metallurgy is thought to follow this sequence: first, cold working of native copper, then annealing, smelting, and, finally, lost-wax casting. In southeastern Anatolia, all four of these techniques appear more or less simultaneously at the beginning of the Neolithic c. 7500 BC.

Copper smelting was independently invented in different places. The earliest evidence of lost-wax casting copper comes from an amulet found in Mehrgarh, Pakistan, and is dated to 4000 BC. Investment casting was invented in 4500–4000 BC in Southeast Asia Smelting was probably discovered in China before 2800 BC, in Central America around 600 AD, and in West Africa about the 9th or 10th century AD. Carbon dating has established mining at Alderley Edge in Cheshire, UK, at 2280 to 1890 BC.

Ötzi the Iceman, a male dated from 3300 to 3200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest an involvement in copper smelting. Experience with copper has assisted the development of other metals; in particular, copper smelting likely led to the discovery of iron smelting. Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6500 and 3000 BC. A copper spearpoint found in Wisconsin has been dated to 6500 BC. Copper usage by the indigenous peoples of the Old Copper Complex from the Great Lakes region of North America has been radiometrically dated to as far back as 7500 BC. Indigenous peoples of North America around the Great Lakes may have also been mining copper during this time, making it one of the oldest known examples of copper extraction in the world. There is evidence from prehistoric lead pollution from lakes in Michigan that people in the region began mining copper c. 6000 BC. Evidence suggests that utilitarian copper objects fell increasingly out of use in the Old Copper Complex of North America during the Bronze Age and a shift towards an increased production of ornamental copper objects occurred.

Bronze Age
Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC. Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use. Bronze artifacts from the Vinča culture date to 4500 BC. Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC. Egyptian Blue, or cuprorivaite (calcium copper silicate) is a synthetic pigment that contains copper and started being used in ancient Egypt around 3250 BC. The manufacturing process of Egyptian blue was known to the Romans, but by the fourth century AD the pigment fell out of use and the secret to its manufacturing process became lost. The Romans said the blue pigment was made from copper, silica, lime and natron and was known to them as caeruleum.

The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, and 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), when copper tools were used with stone tools. The term has gradually fallen out of favor because in some parts of the world, the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.

Ancient and post-classical

In Greece, copper was known by the name (χαλκός). It was an important resource for the Romans, Greeks and other ancient peoples. In Roman times, it was known as aes Cyprium, aes being the generic Latin term for copper alloys and Cyprium from Cyprus, where much copper was mined. The phrase was simplified to cuprum, hence the English copper. Aphrodite (Venus in Rome) represented copper in mythology and alchemy because of its lustrous beauty and its ancient use in producing mirrors; Cyprus, the source of copper, was sacred to the goddess. The seven heavenly bodies known to the ancients were associated with the seven metals known in antiquity, and Venus was assigned to copper, both because of the connection to the goddess and because Venus was the brightest heavenly body after the Sun and Moon and so corresponded to the most lustrous and desirable metal after gold and silver.

Copper was first mined in ancient Britain as early as 2100 BC. Mining at the largest of these mines, the Great Orme, continued into the late Bronze Age. Mining seems to have been largely restricted to supergene ores, which were easier to smelt. The rich copper deposits of Cornwall seem to have been largely untouched, in spite of extensive tin mining in the region, for reasons likely social and political rather than technological.

In North America, native copper is known to have been extracted from sites on Isle Royale with primitive stone tools between 800 and 1600 AD. Copper annealing was being performed in the North American city of Cahokia around 1000–1300 AD. There are several exquisite copper plates, known as the Mississippian copper plates that have been found in North America in the area around Cahokia dating from this time period (1000–1300 AD). The copper plates were thought to have been manufactured at Cahokia before ending up elsewhere in the Midwest and southeastern United States like the Wulfing cache and Etowah plates. In South America a copper mask dated to 1000 BC found in the Argentinian Andes is the oldest known copper artifact discovered in the Andes. Peru has been considered the origin for early copper metallurgy in pre-Columbian America, but the copper mask from Argentina suggests that the Cajón del Maipo of the southern Andes was another important center for early copper workings in South America. Copper metallurgy was flourishing in South America, particularly in Peru around 1000 AD. Copper burial ornamentals from the 15th century have been uncovered, but the metal's commercial production did not start until the early 20th century.

The cultural role of copper has been important, particularly in currency. Romans in the 6th through 3rd centuries BC used copper lumps as money. At first, the copper itself was valued, but gradually the shape and look of the copper became more important. Julius Caesar had his own coins made from brass, while Octavianus Augustus Caesar's coins were made from Cu-Pb-Sn alloys. With an estimated annual output of around 15,000 t, Roman copper mining and smelting activities reached a scale unsurpassed until the time of the Industrial Revolution; the provinces most intensely mined were those of Hispania, Cyprus and in Central Europe.

The gates of the Temple of Jerusalem used Corinthian bronze treated with depletion gilding. The process was most prevalent in Alexandria, where alchemy is thought to have begun. In ancient India, copper was used in the holistic medical science Ayurveda for surgical instruments and other medical equipment. Ancient Egyptians (~2400 BC) used copper for sterilizing wounds and drinking water, and later to treat headaches, burns, and itching.

Modern
The Great Copper Mountain was a mine in Falun, Sweden, that operated from the 10th century to 1992. It satisfied two-thirds of Europe's copper consumption in the 17th century and helped fund many of Sweden's wars during that time. It was referred to as the nation's treasury; Sweden had a copper backed currency.

Copper is used in roofing, currency, and for photographic technology known as the daguerreotype. Copper was used in Renaissance sculpture, and was used to construct the Statue of Liberty; copper continues to be used in construction of various types. Copper plating and copper sheathing were widely used to protect the under-water hulls of ships, a technique pioneered by the British Admiralty in the 18th century. The Norddeutsche Affinerie in Hamburg was the first modern electroplating plant, starting its production in 1876. The German scientist Gottfried Osann invented powder metallurgy in 1830 while determining the metal's atomic mass; around then it was discovered that the amount and type of alloying element (e.g., tin) to copper would affect bell tones.

During the rise in demand for copper for the Age of Electricity, from the 1880s until the Great Depression of the 1930s, the United States produced one third to half the world's newly mined copper. Major districts included the Keweenaw district of northern Michigan, primarily native copper deposits, which was eclipsed by the vast sulphide deposits of Butte, Montana, in the late 1880s, which itself was eclipsed by porphyry deposits of the Southwest United States, especially at Bingham Canyon, Utah, and Morenci, Arizona. Introduction of open pit steam shovel mining and innovations in smelting, refining, flotation concentration and other processing steps led to mass production. Early in the twentieth century, Arizona ranked first, followed by Montana, then Utah and Michigan.

Flash smelting was developed by Outokumpu in Finland and first applied at Harjavalta in 1949; the energy-efficient process accounts for 50% of the world's primary copper production.

The Intergovernmental Council of Copper Exporting Countries, formed in 1967 by Chile, Peru, Zaire and Zambia, operated in the copper market as OPEC does in oil, though it never achieved the same influence, particularly because the second-largest producer, the United States, was never a member; it was dissolved in 1988.

Applications
The major applications of copper are electrical wire (60%), roofing and plumbing (20%), and industrial machinery (15%). Copper is used mostly as a pure metal, but when greater hardness is required, it is put into such alloys as brass and bronze (5% of total use). For more than two centuries, copper paint has been used on boat hulls to control the growth of plants and shellfish. A small part of the copper supply is used for nutritional supplements and fungicides in agriculture. Machining of copper is possible, although alloys are preferred for good machinability in creating intricate parts.

Wire and cable
Despite competition from other materials, copper remains the preferred electrical conductor in nearly all categories of electrical wiring except overhead electric power transmission where aluminium is often preferred. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Electrical wiring is the most important market for the copper industry. This includes structural power wiring, power distribution cable, appliance wire, communications cable, automotive wire and cable, and magnet wire. Roughly half of all copper mined is used for electrical wire and cable conductors. Many electrical devices rely on copper wiring because of its multitude of inherent beneficial properties, such as its high electrical conductivity, tensile strength, ductility, creep (deformation) resistance, corrosion resistance, low thermal expansion, high thermal conductivity, ease of soldering, malleability, and ease of installation.

For a short period from the late 1960s to the late 1970s, copper wiring was replaced by aluminium wiring in many housing construction projects in America. The new wiring was implicated in a number of house fires and the industry returned to copper.

Electronics and related devices
Integrated circuits and printed circuit boards increasingly feature copper in place of aluminium because of its superior electrical conductivity; heat sinks and heat exchangers use copper because of its superior heat dissipation properties. Electromagnets, vacuum tubes, cathode ray tubes, and magnetrons in microwave ovens use copper, as do waveguides for microwave radiation.

Electric motors
Copper's superior conductivity enhances the efficiency of electrical motors. This is important because motors and motor-driven systems account for 43–46% of all global electricity consumption and 69% of all electricity used by industry. Increasing the mass and cross section of copper in a coil increases the efficiency of the motor. Copper motor rotors, a new technology designed for motor applications where energy savings are prime design objectives, are enabling general-purpose induction motors to meet and exceed National Electrical Manufacturers Association (NEMA) premium efficiency standards.

Architecture
Copper has been used since ancient times as a durable, corrosion resistant, and weatherproof architectural material. Roofs, flashings, rain gutters, downspouts, domes, spires, vaults, and doors have been made from copper for hundreds or thousands of years. Copper's architectural use has been expanded in modern times to include interior and exterior wall cladding, building expansion joints, radio frequency shielding, and antimicrobial and decorative indoor products such as attractive handrails, bathroom fixtures, and counter tops. Some of copper's other important benefits as an architectural material include low thermal movement, light weight, lightning protection, and recyclability.

The metal's distinctive natural green patina has long been coveted by architects and designers. The final patina is a particularly durable layer that is highly resistant to atmospheric corrosion, thereby protecting the underlying metal against further weathering. It can be a mixture of carbonate and sulfate compounds in various amounts, depending upon environmental conditions such as sulfur-containing acid rain. Architectural copper and its alloys can also be 'finished' to take on a particular look, feel, or color. Finishes include mechanical surface treatments, chemical coloring, and coatings.

Copper has excellent brazing and soldering properties and can be welded; the best results are obtained with gas metal arc welding.

Antibiofouling
Copper is biostatic, meaning bacteria and many other forms of life will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal and copper-based paint. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions and have strong structural and corrosion-resistant properties in marine environments.

Antimicrobial
Copper-alloy touch surfaces have natural properties that destroy a wide range of microorganisms (e.g., E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Clostridium difficile, influenza A virus, adenovirus, SARS-CoV-2, and fungi). Indians have been using copper vessels since ancient times for storing water, even before modern science realized its antimicrobial properties. Some copper alloys were proven to kill more than 99.9% of disease-causing bacteria within just two hours when cleaned regularly. The United States Environmental Protection Agency (EPA) has approved the registrations of these copper alloys as "antimicrobial materials with public health benefits"; that approval allows manufacturers to make legal claims to the public health benefits of products made of registered alloys. In addition, the EPA has approved a long list of antimicrobial copper products made from these alloys, such as bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, and shopping cart handles. Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in plumbing systems. Antimicrobial copper alloy products are now being installed in healthcare facilities in the U.K., Ireland, Japan, Korea, France, Denmark, and Brazil, as well as being called for in the US, and in the subway transit system in Santiago, Chile, where copper–zinc alloy handrails were installed in some 30 stations between 2011 and 2014. Textile fibers can be blended with copper to create antimicrobial protective fabrics.

Copper demand
Total world production in 2023 is expected to be almost 23 million metric tons. Copper demand is increasing due to the ongoing energy transition to electricity. China accounts for over half the demand.

For some purposes, other metals can substitute, aluminium wire was substituted in many applications, but improper design resulted in fire hazards. The safety issues have since been solved by use of larger sizes of aluminium wire (#8AWG and up), and properly designed aluminium wiring is still being installed in place of copper. For example, the Airbus A380 uses aluminum wire in place of copper wire for electrical power transmission.

Speculative investing
Copper may be used as a speculative investment due to the predicted increase in use from worldwide infrastructure growth, and the important role it has in producing wind turbines, solar panels, and other renewable energy sources. Another reason predicted demand increases is the fact that electric cars contain an average of 3.6 times as much copper as conventional cars, although the effect of electric cars on copper demand is debated. Some people invest in copper through copper mining stocks, ETFs, and futures. Others store physical copper in the form of copper bars or rounds although these tend to carry a higher premium in comparison to precious metals. Those who want to avoid the premiums of copper bullion alternatively store old copper wire, copper tubing or American pennies made before 1982.

Folk medicine
Copper is commonly used in jewelry, and according to some folklore, copper bracelets relieve arthritis symptoms. In one trial for osteoarthritis and one trial for rheumatoid arthritis, no differences were found between copper bracelet and control (non-copper) bracelet. No evidence shows that copper can be absorbed through the skin. If it were, it might lead to copper poisoning.

Degradation
Chromobacterium violaceum and Pseudomonas fluorescens can both mobilize solid copper as a cyanide compound. The ericoid mycorrhizal fungi associated with Calluna, Erica and Vaccinium can grow in metalliferous soils containing copper. The ectomycorrhizal fungus Suillus luteus protects young pine trees from copper toxicity. A sample of the fungus Aspergillus niger was found growing from gold mining solution and was found to contain cyano complexes of such metals as gold, silver, copper, iron, and zinc. The fungus also plays a role in the solubilization of heavy metal sulfides.

Biochemistry
Copper proteins have diverse roles in biological electron transport and oxygen transportation, processes that exploit the easy interconversion of Cu(I) and Cu(II). Copper is essential in the aerobic respiration of all eukaryotes. In mitochondria, it is found in cytochrome c oxidase, which is the last protein in oxidative phosphorylation. Cytochrome c oxidase is the protein that binds the O2 between a copper and an iron; the protein transfers 8 electrons to the O2 molecule to reduce it to two molecules of water. Copper is also found in many superoxide dismutases, proteins that catalyze the decomposition of superoxides by converting it (by disproportionation) to oxygen and hydrogen peroxide:
 * Cu2+-SOD + O2− → Cu+-SOD + O2 (reduction of copper; oxidation of superoxide)
 * Cu+-SOD + O2− + 2H+ → Cu2+-SOD + H2O2 (oxidation of copper; reduction of superoxide)

The protein hemocyanin is the oxygen carrier in most mollusks and some arthropods such as the horseshoe crab (Limulus polyphemus). Because hemocyanin is blue, these organisms have blue blood rather than the red blood of iron-based hemoglobin. Structurally related to hemocyanin are the laccases and tyrosinases. Instead of reversibly binding oxygen, these proteins hydroxylate substrates, illustrated by their role in the formation of lacquers. The biological role for copper commenced with the appearance of oxygen in Earth's atmosphere. Several copper proteins, such as the "blue copper proteins", do not interact directly with substrates; hence they are not enzymes. These proteins relay electrons by the process called electron transfer.

A unique tetranuclear copper center has been found in nitrous-oxide reductase.

Chemical compounds which were developed for treatment of Wilson's disease have been investigated for use in cancer therapy.

Nutrition
Copper is an essential trace element in plants and animals, but not all microorganisms. The human body contains copper at a level of about 1.4 to 2.1 mg per kg of body mass.

Absorption
Copper is absorbed in the gut, then transported to the liver bound to albumin. After processing in the liver, copper is distributed to other tissues in a second phase, which involves the protein ceruloplasmin, carrying the majority of copper in blood. Ceruloplasmin also carries the copper that is excreted in milk, and is particularly well-absorbed as a copper source. Copper in the body normally undergoes enterohepatic circulation (about 5 mg a day, vs. about 1 mg per day absorbed in the diet and excreted from the body), and the body is able to excrete some excess copper, if needed, via bile, which carries some copper out of the liver that is not then reabsorbed by the intestine.

Dietary recommendations
The U.S. Institute of Medicine (IOM) updated the estimated average requirements (EARs) and recommended dietary allowances (RDAs) for copper in 2001. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake (AI) is used instead. The AIs for copper are: 200 μg of copper for 0–6-month-old males and females, and 220 μg of copper for 7–12-month-old males and females. For both sexes, the RDAs for copper are: 340 μg of copper for 1–3 years old, 440 μg of copper for 4–8 years old, 700 μg of copper for 9–13 years old, 890 μg of copper for 14–18 years old and 900 μg of copper for ages 19 years and older. For pregnancy, 1,000 μg. For lactation, 1,300 μg. As for safety, the IOM also sets tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of copper the UL is set at 10 mg/day. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes.

The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States. For women and men ages 18 and older the AIs are set at 1.3 and 1.6 mg/day, respectively. AIs for pregnancy and lactation is 1.5 mg/day. For children ages 1–17 years the AIs increase with age from 0.7 to 1.3 mg/day. These AIs are higher than the U.S. RDAs. The European Food Safety Authority reviewed the same safety question and set its UL at 5 mg/day, which is half the U.S. value.

For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For copper labeling purposes 100% of the Daily Value was 2.0 mg, but, it was revised to 0.9 mg to bring it into agreement with the RDA. A table of the old and new adult daily values is provided at Reference Daily Intake.

Deficiency
Because of its role in facilitating iron uptake, copper deficiency can produce anemia-like symptoms, neutropenia, bone abnormalities, hypopigmentation, impaired growth, increased incidence of infections, osteoporosis, hyperthyroidism, and abnormalities in glucose and cholesterol metabolism. Conversely, Wilson's disease causes an accumulation of copper in body tissues.

Severe deficiency can be found by testing for low plasma or serum copper levels, low ceruloplasmin, and low red blood cell superoxide dismutase levels; these are not sensitive to marginal copper status. The "cytochrome c oxidase activity of leucocytes and platelets" has been stated as another factor in deficiency, but the results have not been confirmed by replication.

Toxicity
Gram quantities of various copper salts have been taken in suicide attempts and produced acute copper toxicity in humans, possibly due to redox cycling and the generation of reactive oxygen species that damage DNA. Corresponding amounts of copper salts (30 mg/kg) are toxic in animals. A minimum dietary value for healthy growth in rabbits has been reported to be at least 3 ppm in the diet. However, higher concentrations of copper (100 ppm, 200 ppm, or 500 ppm) in the diet of rabbits may favorably influence feed conversion efficiency, growth rates, and carcass dressing percentages.

Chronic copper toxicity does not normally occur in humans because of transport systems that regulate absorption and excretion. Autosomal recessive mutations in copper transport proteins can disable these systems, leading to Wilson's disease with copper accumulation and cirrhosis of the liver in persons who have inherited two defective genes.

Elevated copper levels have also been linked to worsening symptoms of Alzheimer's disease.

Human exposure
In the US, the Occupational Safety and Health Administration (OSHA) has designated a permissible exposure limit (PEL) for copper dust and fumes in the workplace as a time-weighted average (TWA) of 1 mg/m3. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 1 mg/m3, time-weighted average. The IDLH (immediately dangerous to life and health) value is 100 mg/m3.

Copper is a constituent of tobacco smoke. The tobacco plant readily absorbs and accumulates heavy metals, such as copper from the surrounding soil into its leaves. These are readily absorbed into the user's body following smoke inhalation. The health implications are not clear.

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title: Copper


text:
European Youth Parliament

The European Youth Parliament is a politically unbound non-profit organisation, which encourages European youth to actively engage in citizenship and cultural understanding. It annually involves around 25,000 youth from across Europe in its events and has around 6,000 active members in the different countries. It was established in 1987 in Fontainebleau, France.

History
The European Youth Parliament was founded by Laurent Grégoire (FR) and Bettina Carr-Allinson (NL), initially, as a school project at the Lycée François-Ier in Fontainebleau, to the south of Paris. It is there that three of the first four International Sessions were held, starting in 1988, about a year after the idea took place.

It then developed steadily for a few years until it moved to Witney, Oxfordshire, in 1991, and was legally recognised as the European Youth Parliament International Ltd., a subsidiary of a charity created in 1992 for this purpose, the Fontainebleau Youth Foundation. The organisation experienced enduring growth for the next ten years, its network counting an increasing number of National Committees and its activities becoming both larger and more numerous. The National Committees stretch beyond the scope of countries within the European Union and try to encompass all European countries.

In the years 2001 to 2004, the EYP encountered various problems of financial nature. On 4 November 2004, however, the European Youth Parliament was reborn due to a mutual agreement between representatives of EYP's Board of National Committees, alumni and the Heinz-Schwarzkopf Foundation. The EYP's status since then has been a programme of the Schwarzkopf-Stiftung Junges Europa, and is hosted in Berlin, Germany.

The actual activities of the EYP never faltered during this period.

Since 2004, the EYP has introduced several reforms to introduce more transparency in its institutions and further enlarged its activities.

Management
At the international level, the EYP is governed by an international board, the Governing Body. The Governing Body has six members elected by the National Committees and by the alumni of past sessions. A representative of the Schwarzkopf Foundation, as well as the EYP's executive director, are also members. The board is largely responsible for the quality assurance of the International Sessions but also takes responsibility for the overall direction of the organisation and the long-term sustainability and protection of the organisation. The day-to-day business of the organisation is administered by a hired manager at the International Office in Berlin. Philipp J. Scharff was the manager from 2004 until 2008, Jan Phillip Beck (DE) from 2008 until 2011, Ville Vasaramäki (FI) from 2011 until 2013, Krista Lagus (FI) from 2013 until 2017 and Lukas Fendel (DE) from 2017 to 2020. Anya Suprunenko was appointed as Executive Director in 2020. In 2022, Pauline Chetail (FR) was made acting Executive Director as Anya went on temporary leave.

At the national level, the National Committees are free to choose how to manage themselves, provided they comply with basic democratic principles. The National Committees are responsible for organising and funding their own national sessions. International Sessions can receive limited funding from EYP at the international level but are also largely responsible for their economy. Sessions are usually funded through sponsorship from various organisations or corporations.

Sessions
EYP organises three international sessions each year. They are organised in different countries and all European countries are invited to join, not just members of the EU. Each country's national committee selects a delegation to participate in each session, the size of which depends on various factors. The delegates are distributed to different committees, each tasked with addressing a particular topic.

Other sessions are organized under the supervision of national boards, including Regional Selection Sessions, National Selection Sessions, International Forums, Small Scale Events and Training Days. National Selection Conferences (sessions) are usually where the selection of the delegations sent to International Sessions takes place. The selection process in most countries (notably excluding France) is taken up by a team of Jurors, led by the Head Of Jury (HoJ), which objectively selects a number of delegates to "pass" on to the next stage.

Each international session starts with a two-day Teambuilding part, in which delegates get acquainted with each other and start improving the group dynamics of the committee. The delegates play different games which are meant to bring the delegates from an initial shyness stage to a comfortable, open atmosphere optimal for efficient Committee work.

This is followed by four or five days for Committee Work. During this time the delegates discuss a problematic topic on current European political matters and write a resolution on how to deal with the issue. A member of the European Parliament or some alternative expert will generally visit once to answer questions and quickly discuss the topic with the Committee.

The sessions end with a General Assembly, in which the committee resolutions are looked through, altered and approved (or if the resolution is found unacceptable, not approved). If a resolution is approved it is sent on to the European Parliament, for the consideration of MEPs. General Assembly is usually held in some honorary or prestigious location, such as the host country's Houses of Parliament or the main hall of the City Council.

Additionally, National Committees of EYP organise several national and regional sessions every year. National sessions are to select a delegation for one of the upcoming international sessions. These sessions are shorter, normally lasting three days and do not invite a member of the European Parliament to the committees. Regional sessions are of varying length, from 3 to 7 or 8 days, and in essence, imitate international sessions. They have, however, a more constrained budget and tend to be less formal than international sessions. For both national and regional sessions, resolutions are not sent to the European Parliament.

As of Spring 2019, 90 (taking into account the Extraordinary International Session of EYP in Lillehammer, Norway, Winter 2010) international EYP sessions have taken place:

 * 1st International Session in Fontainebleau, France, 1988
 * 2nd International Session in Fontainebleau, France, 1989
 * 3rd International Session in Thessaloniki, Greece, 1989
 * 4th International Session in Fontainebleau, France, 1990
 * 5th International Session in Lisbon, Portugal, 1990
 * 6th International Session in Kronberg, Germany, 1990
 * 7th International Session in Prague, Czech Republic, 1991
 * 8th International Session in Barcelona, Spain, 1991
 * 9th International Session in Oxford, United Kingdom, 1992
 * 10th International Session in Strasbourg, France, 1992
 * 11th International Session in Ghent, Belgium, 1992
 * 12th International Session in Budapest, Hungary, 1993
 * 13th International Session in Luxembourg, Luxembourg, 1993
 * 14th International Session in Fontainebleau, France, 1993
 * 15th International Session in Berlin, Germany, 1994
 * 16th International Session in Brussels, Belgium, 1994
 * 17th International Session in Holstebro, Denmark, 1994
 * 18th International Session in Gothenburg, Sweden, 1995
 * 19th International Session in Dublin, Ireland, 1995
 * 20th International Session in Milan, Italy, 1995
 * 21st International Session in Helsinki, Finland, 1996
 * 22nd International Session in Munich, Germany, 1996
 * 23rd International Session in Nicosia, Cyprus, 1996
 * 24th International Session in Thessaloniki, Greece, 1997
 * 25th International Session in Barcelona, Spain, 1997
 * 26th International Session in Edinburgh, United Kingdom, 1997
 * 27th International Session in Granada, Spain, 1998
 * 28th International Session in Brussels, Belgium, 1998
 * 29th International Session in Vienna, Austria, 1998
 * 30th International Session in Rome, Italy, 1999
 * 31st International Session in Weimar, Germany, 1999
 * 32nd International Session in Hämeenlinna, Finland, 1999
 * 33rd International Session in Athens, Greece, 2000
 * 34th International Session in Bern, Switzerland, 2000
 * 35th International Session in Oxford, United Kingdom, 2000
 * 36th International Session in Stockholm, Sweden, 2001
 * 37th International Session in Dubrovnik, Croatia, 2001
 * 38th International Session in Porto, Portugal, 2001
 * 39th International Session in Riga, Latvia, 2002
 * 40th International Session in Ghent, Belgium, 2002
 * 41st International Session in Turin, Italy, 2002
 * 42nd International Session in Prague, Czech Republic, 2003
 * 43rd International Session in Dublin, Ireland, 2003
 * 44th International Session in Tallinn, Estonia, 2003
 * 45th International Session in Durham, United Kingdom, 2004
 * 46th International Session in Tábor, Czech Republic, 2004
 * 47th International Session in Berlin, Germany, 2004
 * 48th International Session in Stavanger, Norway, Spring 2005
 * 49th International Session in Basel, Switzerland, Summer 2005
 * 50th International Session in Bari, Italy, Autumn 2005
 * 51st International Session in Paris, France, Spring 2006
 * 52nd International Session in Ventspils-Riga, Latvia, Summer 2006
 * 53rd International Session in Kyiv, Ukraine, Autumn 2006
 * 54th International Session in Potsdam, Germany, Spring 2007
 * 55th International Session in Białystok, Poland, Summer 2007
 * 56th International Session in Dublin, Ireland, Autumn 2007
 * 57th International Session in Prague, Czech Republic Spring 2008
 * 58th International Session in Liverpool, United Kingdom, Summer 2008
 * 59th International Session in Rennes, France, Autumn 2008
 * 60th International Session in Stockholm, Sweden, Spring 2009
 * 61st International Session in Leuven, Belgium, Summer 2009
 * 62nd International Session in Helsinki, Finland, Autumn 2009
 * 63rd International Session in Tromsø, Norway, Spring 2010
 * 64th International Session in Frankfurt, Germany, Summer 2010
 * 65th International Session in Lviv, Ukraine, Autumn 2010
 * Extraordinary International Session in Lillehammer, Norway, Winter 2010
 * 66th International Session in Athens, Greece, Spring 2011
 * 67th International Session in Grenoble, France, Summer 2011
 * 68th International Session in Zagreb, Croatia, Autumn 2011
 * 69th International Session in Istanbul, Turkey, Spring 2012
 * 70th International Session in Tallinn, Estonia, Summer 2012
 * 71st International Session in Amsterdam, The Netherlands, Autumn 2012
 * 72nd International Session in Munich, Germany, Spring 2013
 * 73rd International Session in Zürich, Switzerland, Summer 2013
 * 74th International Session in Tbilisi, Georgia, Autumn 2013
 * 75th International Session in Riga, Latvia, Spring 2014
 * 76th International Session in Barcelona, Spain, Summer 2014
 * 77th International Session in Kyiv, Ukraine, Autumn 2014 (cancelled for political instability)
 * 78th International Session in İzmir, Turkey, Spring 2015
 * 79th International Session in Tampere, Finland, Summer 2015
 * 80th International Session in Leipzig, Germany, Autumn 2015
 * 81st International Session in Dublin, Ireland and Belfast, United Kingdom, Spring 2016
 * 82nd International Session in Rennes, France, Summer 2016
 * 83rd International Session in Laax, Switzerland, Autumn 2016
 * 84th International Session in Trondheim, Norway, Spring 2017
 * 85th International Session in Brno, Czech Republic, Summer 2017
 * 86th International Session in Tbilisi, Georgia, Autumn 2017
 * 87th International Session in Vilnius, Lithuania, Summer 2018
 * 88th International Session in Rotterdam, The Netherlands, Autumn 2018
 * 89th International Session in Yerevan, Armenia, Spring 2019
 * 90th International Session in Valencia, Spain, Summer 2019
 * 91st International Session in Hamburg, Germany, Autumn 2019
 * 92nd International Session in Milan, Italy, Spring 2021 (planned for Spring 2020, but due to Covid postponed to 2021)
 * 93rd International Session in Warsaw, Poland, Summer 2021
 * 94th International Session in Ljubljana, Slovenia, Summer 2021
 * 95th International Session in Novi Sad, Serbia, Spring 2022
 * 96th International Session in Riga, Latvia, Summer 2022
 * 97th International Session in Kortrijk, Belgium, Autumn 2022
 * 98th International Session in Tromsø, Norway, Spring 2023
 * 99th International Session in Baku, Azerbaijan, Summer 2023

Future sessions will include:
 * 100th International Session in Thessaloniki, Greece, Summer 2024
 * 101st International Session in The Hague, The Netherlands, Spring 2025
 * 102nd International Session in Turku, Finland, Summer 2025
 * 103rd International Session in Málaga, Spain, Autumn 2025

title: European Youth Parliament


text:
Talk:Trail riding

Untitled
This page violates the Neutral Point of View. It needs a considerable rewrite. -- Robert Merkel

It is also skewed towards bicycle and motorcycles. Environmentalists rarely have anything against horses. --Anders Törlind

Yes, this page was written with a strong agenda, and one with which I do not agree, having performed thousands of hours of trail planning, design, construction, and maintenance. Actually, horses are almost as negatively-impacting on trails as are motorcycles. Even mountain bikes negatively impact trails relevant to foot hiking. Ideally, all these four trail types should be kept strictly separate, certainly at least because all three of the other uses make life 'miserable' for foot-hikers. -- John Knouse

 * Then why don't you do something about it Mr Know-it-all -Bennyboyz3000 18:32, 4 March 2007 (UTC)

parking factoids for now
Pulled this from the main article and putting it here for now. Nothing bad about it, just my concern is that once we start naming specific trails, it will never end. (e.g. Appalachian trail, Continental Divide Trail, etc...) Open to discussion, but putting it here for now so as not to "prime the pump" for more... Montanabw (talk) 23:59, 9 October 2008 (UTC)

The Bicentennial National Trail in Australia is the longest marked multi-use trail in the world, stretching 5,330 kilometres from Cooktown, Queensland, through New South Wales to Healesville, Victoria. This trail runs the length of the rugged Great Dividing Range through national parks, private property and alongside of wilderness areas. One of the objectives was to develop a trail that linked up the brumby tracks, mustering and stock routes along the Great Dividing Range, thus providing an opportunity to legally ride the routes of stockmen and drovers who once travelled these areas with pack horses. This Trail provides access to some of the wildest, most remote country in the world. The Bicentennial National Trail is suitable for self-reliant horse riders, fit walkers and mountain bike riders.

Mountain biking
Am I right in thinking that trail riding for mountain bikers normally refers to relatively short trails, whereas for equestrians it can include multi-day long distance trails and extended excursion. Also how long is the average mountain bike trail? My initial impression is that is there some difference in the usage of the term trail riding? And do mountain bikers follow long distance paths, backpack/camp?Rwood128 (talk) 01:17, 22 October 2014 (UTC)

I now realize that the above is excessively naive (it's late in the evening), as I have met met mountain bikers on GRs in France, and mountain trails in Switzerland, the Highlands and Lake District, etc! But still, is the term also used for bike rides on short trails? Rwood128 (talk) 01:42, 22 October 2014 (UTC)

 * Yes, I would say that 'trail' is the prefered term for for all lengths and, perhaps confusingly, for pretty much all types of trail too. My local trail centre has a 'Family trail' (a flat 12 mile loop) and 'downhill trails' (short specialised runs) on the same site. Obscurasky (talk) 08:58, 22 October 2014 (UTC)
 * That is true (the overview definition). Keep in mind that this was originally an equestrian-focused article. ;-)   Montanabw (talk)  06:57, 23 October 2014 (UTC)

Thanks. I'm beginning to wonder if trail riding would not be better dealt with in the Mountain biking and Bridle path pages, and that a section on Trail centres should be started on the MB page, rather than as a new article. What do you think? Rwood128 (talk) 11:59, 22 October 2014 (UTC)

 * Speaking only from the horse side, a "trail ride" can be anything from a couple miles in an hour (common on some guest ranches) to a half day (very common) to full day and multi-day outings. Here in the American West, while some trails are more suited to horses or mountain bikes, and in more populated areas they may be segregated to some degree (for safety, if nothing else) they technically use the same Forest Service trails in many places. A "bridle path" is a term confined mostly to short paths in the UK and to a lesser extent, eastern North America.  A bridle path is like trail riding light!    Montanabw (talk)  06:57, 23 October 2014 (UTC)

Cycle touring
Is there some overlap between Cycle touring and trail riding? Also do you have to be on a mountain bike to trail ride?Rwood128 (talk) 21:40, 22 October 2014 (UTC)

 * In the USA, I'd say no; it would be a huge difference, roads are not "trails" here (occasional historic naming notwithstanding) - and while you could trail ride on something other than a mountain bike here, you'd be a complete idiot with a death wish!  Montanabw (talk)  06:46, 23 October 2014 (UTC)

Many thanks.

Am I right in thinking that there are different kinds of mountain bike trail riding? That is: Rwood128 (talk) 12:00, 23 October 2014 (UTC)
 * (1) On short, steep, highly technical, constructed trails;
 * 2) On longer, fairly level trails, like bridle paths, rail trails, farm and forest roads (The South Downs Way in England would be an example);
 * (3) On hiking trails that can include steep mountain trails and high passes;
 * (4) Rides that can last for days? I encountered mountain bikers on a French Grande Randonnée who had their luggage transported for them. Hence my question about cycle touring

This image from Cycle touring is of interest here. They don't look like mountain bikes to me but aren't they also trail riding?. See also Dervla Murphy and Mixed Terrain Cycle-Touring. Rwood128 (talk) 12:19, 23 October 2014 (UTC)

 * Nah, that's a road, in my view. I know that people in the US will do multi-day bicycle trips, mostly on roads.  I really don't know much about mountain biking other than I'm too scared to do (1) and too lazy for  (3)!   In the USA, (2) would not be "trail" riding - roads - even gravel ones - aren't "trails"  - that said, our definition of "road" is pretty generous.  Montanabw (talk)  07:07, 26 October 2014 (UTC)

I agree that the trail in Patagonia looks like an unpaved road, but the surface is very similar to that of shown on other images.

Re (2), while the South Downs Way is often fairly level, there is also some serious climbing, and the path is rough and stony in places. It is also of course a National Trail. The Ohio and Erie Canal tow path is obviously level, but the surface isn't suitable for regular bikes. But we need mountain bikers from different parts of the world to clarify this matter. Rwood128 (talk) 12:37, 26 October 2014 (UTC)

 * In fact riding a trail, even a flat towpath or rail trail, on a horse (or other animal), or any kind of bike (not just hybrids and mountain bikes) is surely a form of trail riding, whatever the surface of the path. This would, however, presumably exclude cycling that takes place solely on roads open to motorised vehicles. Rwood128 (talk) 13:59, 26 October 2014 (UTC)

 * And if you want to really complicate matters,  there are places where they allow motorcycles to "trail ride" (at least out here in the west, and it's a very controversial issue).  I guess for me, pavement - or at least gravel to create an all-weather surface - is one way to distinguish between a trail and a road - certainly some very high traffic trails are also paved, and some roads open to motorized cars and trucks are not, (and we won't even start to discuss what a "jeep trail" is...)  OTOH, horses generally should not be ridden on pavement or heavy gravel, (with many exceptions of course, parades, working equines in cities like carriage or police horses, etc...) so maybe the way to structure this article is by mode of transport; horses, bicycles, etc., rather than type of trails?   Montanabw (talk)  05:29, 29 October 2014 (UTC)

According to the lede this article can include motorised trail riding. I don't follow your comment re the structure of the article. At the moment it is basically divided into two main sections that deal with horses and bikes separately, and the 'Rail trail' section, which involves multi-use. There is some overlap, however, because of bridleways (in Britain) and towpaths. Rwood128 (talk) 14:22, 29 October 2014 (UTC)

Proposed deletion/ partial merger with "Trail"
This article duplicates an existing article: Trail. The existing article is much better written, more comprehensive. I propose deleting this article, or merging the content where appropriate. Fluous (talk) 20:44, 21 December 2014 (UTC)
 * There is some overlap, but it's overstating it to say the two pages are duplicates. It should also be noted that there are over 40 other pages linking to this page, and almost all of those links relate specifically to the practice of 'trail riding', not actual 'trails'. Obscurasky (talk) 23:22, 21 December 2014 (UTC)

 * There's probably is too much emphasis on describing trails rather than discussing trail riding, but that can be remedied, so that a merge -- or deletion-- isn't really appropriate. But the criticism is useful.Rwood128 (talk) 23:33, 21 December 2014 (UTC)

 * Oppose merge: This article is about the recreational activity, the other is about trails themselves.  No reason we can't improve this article, but a merge is not suitable. Montanabw (talk)  21:56, 22 December 2014 (UTC)

Article improvement
Per the comments above, I took a whack at the article and tossed quite a bit of material about the individual trails. I have no intent of "dissing" anyone's trail, but I think the specifics belong elsewhere. Anyone wanting to keep material not mentioned in any other article can just copy from the old version prior to my edit today ( Montanabw (talk) ) and put it in whatever article they want. I didn't do much with sourcing, this was more of a copyedit. Feel free to continue to make other improvements! Montanabw (talk) 22:30, 22 December 2014 (UTC)

This looks good -- I suspect that I may be guilty of adding off-topic material. Rwood128 (talk) 23:31, 22 December 2014 (UTC)

title: Talk:Trail riding