Editing Iron (section)

==History==
{{Main|History of ferrous metallurgy}}

===Development of iron metallurgy===
Iron is one of the elements undoubtedly known to the ancient world.{{sfn|Weeks|1968|p=4}} It has been worked, or [[wrought iron|wrought]], for millennia. However, iron artefacts of great age are much rarer than objects made of gold or silver due to the ease with which iron corrodes.{{sfn|Weeks|1968|p=29}} The technology developed slowly, and even after the discovery of smelting it took many centuries for iron to replace bronze as the metal of choice for tools and weapons.

====Meteoritic iron====
[[File:Meteorite iron harpoon.jpg|thumb|Iron harpoon head from [[Greenland]]. The iron edge covers a [[narwhal]] tusk harpoon using meteorite iron from the [[Cape York meteorite]], one of the largest iron meteorites known.]]
Beads made from [[meteoric iron]] in 3500 BC or earlier were found in [[Gerzeh culture|Gerzeh]], Egypt by [[G. A. Wainwright]].{{sfn|Weeks|1968|p=31}}<!-- Typo on page 31 refers to "G. W." but reference at end of chapter says "G. A." --> The beads contain 7.5% nickel, which is a signature of meteoric origin since iron found in the Earth's crust generally has only minuscule nickel impurities.

Meteoric iron was highly regarded due to its origin in the heavens and was often used to forge weapons and tools.{{sfn|Weeks|1968|p=31}} For example, a [[Tutankhamun's iron dagger blade|dagger]] made of meteoric iron was found in the tomb of [[Tutankhamun]], containing similar proportions of iron, cobalt, and nickel to a meteorite discovered in the area, deposited by an ancient meteor shower.<ref name="Bjorkman 1973">{{cite journal|last=Bjorkman|first=Judith Kingston|title=Meteors and Meteorites in the ancient Near East |journal=Meteoritics |date=1973 |pages=91–132 |doi=10.1111/j.1945-5100.1973.tb00146.x |volume=8|issue=2|bibcode=1973Metic...8...91B}}</ref><ref name="Comelli">{{cite journal|doi=10.1111/maps.12664 |bibcode=2016M&PS...51.1301C|title=The meteoritic origin of Tutankhamun's iron dagger blade|journal=Meteoritics & Planetary Science|volume=51|issue=7|pages=1301–09|year=2016|last1=Comelli|first1=Daniela|last2=d'Orazio|first2=Massimo|last3=Folco|first3=Luigi|last4=El-Halwagy|first4=Mahmud|last5=Frizzi|first5=Tommaso|last6=Alberti|first6=Roberto|last7=Capogrosso|first7=Valentina|last8=Elnaggar|first8=Abdelrazek|last9=Hassan|first9=Hala|last10=Nevin|first10=Austin|last11=Porcelli|first11=Franco|last12=Rashed|first12=Mohamed G|last13=Valentini|first13=Gianluca|doi-access=free}}</ref><ref name="walshx">{{cite news | last=Walsh | first=Declan | title=King Tut's Dagger Made of 'Iron From the Sky,' Researchers Say | newspaper=[[The New York Times]] | quote=the blade's composition of iron, nickel and cobalt was an approximate match for a meteorite that landed in northern Egypt. The result "strongly suggests an extraterrestrial origin" | date=2 June 2016 | url=https://www.nytimes.com/2016/06/03/world/middleeast/king-tuts-dagger-made-of-iron-from-the-sky-researchers-say.html |archive-url=https://ghostarchive.org/archive/20220103/https://www.nytimes.com/2016/06/03/world/middleeast/king-tuts-dagger-made-of-iron-from-the-sky-researchers-say.html |archive-date=2022-01-03 |url-access=subscription |url-status=live | access-date=4 June 2016}}{{cbignore}}</ref> Items that were likely made of iron by Egyptians date from 3000 to 2500 BC.{{sfn|Weeks|1968|p=29}}

Meteoritic iron is comparably soft and ductile and easily [[cold forging|cold forged]] but may get brittle when heated because of the [[nickel]] content.<ref>{{Cite book|url={{Google books|-CQ4AQAAIAAJ|page=PA492|keywords=|text=|plainurl=yes}}|title=Technisches wörterbuch oder Handbuch der Gewerbskunde ... : Bearb. nach Dr. Andrew Ure's Dictionary of arts, manufactures and mines|last=Ure|first=Andrew|date=1843|publisher=G. Haase|page=492|language=de}}</ref>

====Wrought iron====
{{Main|Wrought iron}}
{{Further|Ancient iron production}}
[[File:Mars symbol (fixed width).svg|left|thumb|upright=0.5|alt=A circle, with a short, simple arrow shape extending diagonally upwards and rightwards from its edge|The symbol for [[Mars]] has been used since antiquity to represent iron.]] [[File:QtubIronPillar.JPG|thumb|alt=A pillar, slightly fluted, with some ornamentation at its top. It is black, slightly weathered to a dark brown near the base. It is around {{convert|7|m|ft|abbr=off|sp=us}} tall. It stands upon a raised circular base of stone, and is surrounded by a short, square fence.|The [[iron pillar of Delhi]] is an example of the iron extraction and processing methodologies of early India.]]

The first iron production started in the [[Middle Bronze Age]], but it took several centuries before iron displaced bronze. Samples of [[smelting|smelted]] iron from [[Asmar]], Mesopotamia and Tall Chagar Bazaar in northern Syria were made sometime between 3000 and 2700 BC.{{sfn|Weeks|1968|p=32}} The [[Hittites]] established an empire in north-central [[Anatolia]] around 1600 BC. They appear to be the first to understand the production of iron from its ores and regard it highly in their society.<ref>McNutt, Paula (1990 1). The Forging of Israel: Iron Technology, Symbolism and Tradition in Ancient Society. A&C Black.</ref> The [[Hittites]] began to smelt iron between 1500 and 1200 BC and the practice spread to the rest of the Near East after their empire fell in 1180 BC.{{sfn|Weeks|1968|p=32}} The subsequent period is called the [[Iron Age]].

Artifacts of smelted iron are found in [[History of metallurgy in the Indian subcontinent|India]] dating from 1800 to 1200 BC,<ref name="Tewari">{{cite web| url = https://antiquity.ac.uk/projgall/tewari/tewari.pdf|first = Rakesh|last = Tewari|title = The origins of Iron Working in India: New evidence from the Central Ganga plain and the Eastern Vindhyas|publisher = State Archaeological Department|access-date = 23 May 2010}}</ref> and in the [[Levant]] from about 1500 BC (suggesting smelting in [[Anatolia]] or the [[Caucasus]]).<ref>{{Cite journal|doi=10.1080/00438243.1989.9980081|last=Photos|first = E.|title=The Question of Meteoritic versus Smelted Nickel-Rich Iron: Archaeological Evidence and Experimental Results|journal=World Archaeology |volume=20 |issue=3 |date=1989 |pages=403–21|publisher=Taylor & Francis, Ltd.|jstor = 124562}}</ref><ref>{{Cite book| last = Muhly|first = James D.|chapter = Metalworking/Mining in the Levant|pages = 174–83|title =Near Eastern Archaeology IN: Eisenbrauns |editor = Lake, Richard Winona |date = 2003|volume = 180}}</ref> Alleged references (compare [[history of metallurgy in South Asia]]) to iron in the Indian [[Vedas]] have been used for claims of a very early usage of iron in India respectively to date the texts as such. The [[rigveda]] term ''ayas'' (metal) refers to copper, while iron which is called as ''śyāma ayas'', literally "black copper", first is mentioned in the post-rigvedic [[Atharvaveda]].<ref>[[Michael Witzel|Witzel, Michael]] (2001), [https://www.people.fas.harvard.edu/~witzel/EJVS-7-3.pdf "Autochthonous Aryans? The Evidence from Old Indian and Iranian Texts"], in ''Electronic Journal of Vedic Studies'' (EJVS) 7-3, pp. 1–93</ref>

Some archaeological evidence suggests iron was smelted in [[Zimbabwe]] and southeast Africa as early as the eighth century BC.<ref>Weeks, p. 33, quoting Cline, Walter (1937) "Mining and Metallurgy in Negro Africa", George Banta Publishing Co., Menasha, Wis., pp. 17–23.</ref> Iron working was introduced to [[Ancient Greece|Greece]] in the late 11th century BC, from which it spread quickly throughout Europe.<ref>Riederer, Josef; Wartke, Ralf-B. (2009) "Iron", Cancik, Hubert; Schneider, Helmuth (eds.): [[Brill's New Pauly]], Brill.</ref>

[[File:1255 - Keramikos Museum, Athens - Iron tool - Photo by Giovanni Dall'Orto, Nov 12 2009.jpg|left|thumb|Iron sickle from Ancient Greece]]
The spread of ironworking in Central and Western Europe is associated with [[Celts|Celtic]] expansion. According to [[Pliny the Elder]], iron use was common in the [[Ancient Rome|Roman]] era.{{sfn|Weeks|1968|p=31}} In the lands of what is now considered [[China]], iron appears approximately 700–500 BC.<ref>Sawyer, Ralph D. and Sawyer, Mei-chün (1993). ''The Seven Military Classics of Ancient China.'' Boulder: Westview. {{ISBN|0-465-00304-4}}. p. 10.</ref> Iron smelting may have been introduced into China through Central Asia.<ref name="pigott2">Pigott, Vincent C. (1999). ''The Archaeometallurgy of the Asian Old World''. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. {{ISBN|0-924171-34-0}}, p. 8.</ref> The earliest evidence of the use of a [[blast furnace]] in China dates to the 1st century AD,<ref name="Golas1999">{{cite book|last=Golas |first= Peter J. |title=Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology, Part 13, Mining|url={{Google books|TSiII7s2wLkC|page=PA152|keywords=|text=|plainurl=yes}}|date= 1999|publisher=Cambridge University Press|isbn=978-0-521-58000-7|page=152|quote=earliest blast furnace discovered in China from about the first century AD}}</ref> and cupola furnaces were used as early as the [[Warring States period]] (403–221 BC).<ref name="pigott">Pigott, Vincent C. (1999). ''The Archaeometallurgy of the Asian Old World''. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. {{ISBN|0-924171-34-0}}, p. 191.</ref> Usage of the blast and cupola furnace remained widespread during the [[Tang dynasty|Tang]] and [[Song dynasty|Song]] dynasties.<ref name="The Coming of the Ages of Steel">{{cite book|title=The Coming of the Ages of Steel|url={{Google books|uMwUAAAAIAAJ|page=PA54|keywords=|text=|plainurl=yes}}|publisher=Brill Archive|page=54|date=1961}}</ref>

During the Industrial Revolution in Britain, [[Henry Cort]] began refining iron from [[pig iron]] to [[wrought iron]] (or bar iron) using innovative production systems. In 1783 he patented the [[Puddling (metallurgy)|puddling process]] for refining iron ore. It was later improved by others, including [[Joseph Hall (metallurgist)|Joseph Hall]].<ref>{{cite journal|doi=10.1179/tns.1977.011|title=Dry and Wet Puddling|journal=Transactions of the Newcomen Society|volume=49|pages=156–57|year=2014|last1=Mott|first1=R.A}}</ref>

====Cast iron====
{{Main|Cast iron}}
[[Cast iron]] was first produced in China during 5th century BC,<ref>{{Cite journal|last=Wagner |first= Donald B.|url=https://hist-met.org/images/Journal_PDFs/37_1_p_25_Wagner.pdf|title=Chinese blast furnaces from the 10th to the 14th century|journal=Historical Metallurgy|volume=37|issue=1|date=2003|pages=25–37|access-date=7 January 2018|archive-url=https://web.archive.org/web/20180107175015/https://hist-met.org/images/Journal_PDFs/37_1_p_25_Wagner.pdf|archive-date=7 January 2018|url-status=dead}} originally published in {{Cite journal|first =Donald B.|last =Wagner|title=Chinese blast furnaces from the 10th to the 14th century|journal=West Asian Science, Technology, and Medicine|volume=18 |date=2001|pages=41–74|doi =10.1163/26669323-01801008}}</ref> but was hardly in Europe until the medieval period.<ref>Giannichedda, Enrico (2007): [https://books.google.com/books?id=LAgxAJNXhFwC&pg=PA200 "Metal production in Late Antiquity"], in ''Technology in Transition AD 300–650'' Lavan, L.; Zanini, E. and Sarantis, A.(eds.), Brill, Leiden; {{ISBN|90-04-16549-5}}, p. 200.</ref><ref name="Biddle">{{Cite book| title = Chemistry, Precision and Design|publisher = A Beka Book, Inc.|first1 = Verne|last1 =Biddle|first2= Gregory|last2 =Parker}}</ref><!--Missing page numbers (how would you add them?)--> The earliest cast iron artifacts were discovered by archaeologists in what is now modern [[Luhe County]], [[Jiangsu]] in China. Cast iron was used in [[ancient China]] for warfare, agriculture, and architecture.<ref name="Wagner">{{cite book|last=Wagner |first= Donald B. |title=Iron and Steel in Ancient China|date=1993|publisher=Brill|isbn=978-90-04-09632-5|pages=335–340}}</ref> During the [[medieval]] period, means were found in Europe of producing wrought iron from cast iron (in this context known as [[pig iron]]) using [[finery forge]]s. For all these processes, [[charcoal]] was required as fuel.{{sfn|Greenwood|Earnshaw|1997|p=1072}}
[[File:Philipp Jakob Loutherbourg d. J. 002.jpg|thumb|''[[Coalbrookdale by Night]]'', 1801. Blast furnaces light the iron making town of [[Coalbrookdale]].]]
Medieval [[blast furnaces]] were about {{convert|10|ft|m}} tall and made of fireproof brick; forced air was usually provided by hand-operated bellows.<ref name="Biddle" /> Modern blast furnaces have grown much bigger, with hearths fourteen meters in diameter that allow them to produce thousands of tons of iron each day, but essentially operate in much the same way as they did during medieval times.{{sfn|Greenwood|Earnshaw|1997|p=1072}}

In 1709, [[Abraham Darby I]] established a [[Coke (fuel)|coke]]-fired blast furnace to produce cast iron, replacing charcoal, although continuing to use blast furnaces. The ensuing availability of inexpensive iron was one of the factors leading to the [[Industrial Revolution]]. Toward the end of the 18th century, cast iron began to replace wrought iron for certain purposes, because it was cheaper. Carbon content in iron was not implicated as the reason for the differences in properties of wrought iron, cast iron, and steel until the 18th century.{{sfn|Weeks|1968|p=32}}

Since iron was becoming cheaper and more plentiful, it also became a major structural material following the building of the innovative [[The Iron Bridge|first iron bridge]] in 1778. This bridge still stands today as a monument to the role iron played in the Industrial Revolution. Following this, iron was used in rails, boats, ships, aqueducts, and buildings, as well as in iron cylinders in [[steam engine]]s.{{sfn|Greenwood|Earnshaw|1997|p=1072}} Railways have been central to the formation of modernity and ideas of progress<ref>Schivelbusch, G. (1986) The Railway Journey: Industrialization and Perception of Time and Space in the 19th Century. Oxford: Berg.</ref> and various languages refer to railways as ''iron road'' (e.g. French {{Lang|fr|chemin de fer}}, German {{Lang|de|Eisenbahn}}, Turkish {{Lang|tr|demiryolu}}, Russian {{Lang|ru|железная дорога}}, [[CJK|Chinese, Japanese, and Korean]] 鐵道, Vietnamese ''{{Lang|vi|đường sắt}}'').

====Steel====
{{Main|Steel}}
{{See also|Steelmaking}}
Steel (with smaller carbon content than pig iron but more than wrought iron) was first produced in antiquity by using a [[bloomery]]. Blacksmiths in [[Luristan]] in western Persia were making good steel by 1000 BC.{{sfn|Weeks|1968|p=32}} Then improved versions, [[Wootz steel]] by India and [[Damascus steel]] were developed around 300 BC and AD 500 respectively. These methods were specialized, and so steel did not become a major commodity until the 1850s.<ref>Spoerl, Joseph S. [https://www.anselm.edu/homepage/dbanach/h-carnegie-steel.htm A Brief History of Iron and Steel Production] {{webarchive|url=https://web.archive.org/web/20100602031459/https://www.anselm.edu/homepage/dbanach/h-carnegie-steel.htm |date=2 June 2010 }}. Saint Anselm College</ref>

New methods of producing it by [[carburizing]] bars of iron in the [[cementation process]] were devised in the 17th century. In the [[Industrial Revolution]], new methods of producing bar iron without charcoal were devised and these were later applied to produce steel. In the late 1850s, [[Henry Bessemer]] invented a new steelmaking process, involving blowing air through molten pig iron, to produce mild steel. This made steel much more economical, thereby leading to wrought iron no longer being produced in large quantities.<ref>{{cite book | url={{Google books|fUmTX8yKU4gC|page=PA190|keywords=|text=|plainurl=yes}} | pages = 190–91 | title = Encyclopedia of the Elements: Technical Data – History – Processing – Applications | isbn = 978-3-527-61234-5 | last1 = Enghag | first1 = Per | date = 8 January 2008| publisher = John Wiley & Sons }}</ref>

===Foundations of modern chemistry===
In 1774, [[Antoine Lavoisier]] used the reaction of water steam with metallic iron inside an incandescent iron tube to produce [[hydrogen]] in his experiments leading to the demonstration of the [[conservation of mass]], which was instrumental in changing chemistry from a qualitative science to a quantitative one.<ref>{{cite journal|doi=10.1021/ed052p658|title=An historical note on the conservation of mass|journal=Journal of Chemical Education|volume=52|issue=10|page=658|year=1975|last1=Whitaker|first1=Robert D|bibcode=1975JChEd..52..658W}}
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===Recent discoveries===
* discovery of [[Mössbauer effect]]
* many enzymes use iron in the catalytic center
* Nickel-56 is the natural end product of silicon burning in massive stars. However, nickel-56 decays to cobalt-56 and then to stable iron-56, ultimately making iron the most abundant heavy element produced by that nucleosynthesis.
* superconductivity?
* magnetic effect
* [[ferrocene]] -->