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Iron, called as Ayas (Samskrit: अयस्) heralded a new era in the history of mankind. Iron technology has a special place among the ancient technologies that accelerated the pace of progress and brought prosperity in society. In human history Iron Age succeeded Copper-Bronze Age as iron required a different kind of skill and a higher level of metallurgical expertise. The craftsmen who were adept in working with copper and its alloys and other glittering metals like gold, silver etc., that could be used in their native form at a much lower temperature could not smelt iron with the same technique. India has rich iron ore deposit. The ore is not only widely distributed but also easily accessible in the form of nodules scattered on the earth's surface. This must have facilitated easy hand picking of rich ore nodules by the early or primitive metal workers. However, wide distribution and easy access to the ore were insufficient to produce metallic iron and required skilled metal workers possessing sufficient metallurgical know-how. Archeological researches and archival accounts including foreign records by travelers or historians of ancient India bear that Indian iron and steel had gained significant recognition in the ancient world.<ref name=":0">Vibha Tripathi,  ''Aspects of Iron Technology in India'' in Propagation, vol 3-1, 2012</ref>  

Iron, called as Ayas (Samskrit: अयस्) heralded a new era in the history of mankind. Iron technology has a special place among the ancient technologies that accelerated the pace of progress and brought prosperity in society. In human history Iron Age succeeded Copper-Bronze Age as iron required a different kind of skill and a higher level of metallurgical expertise. The craftsmen who were adept in working with copper and its alloys and other glittering metals like gold, silver etc., that could be used in their native form at a much lower temperature could not smelt iron with the same technique. India has rich iron ore deposit. The ore is not only widely distributed but also easily accessible in the form of nodules scattered on the earth's surface. This must have facilitated easy hand picking of rich ore nodules by the early or primitive metal workers. However, wide distribution and easy access to the ore were insufficient to produce metallic iron and required skilled metal workers possessing sufficient metallurgical know-how. Archeological researches and archival accounts including foreign records by travelers or historians of ancient India bear that Indian iron and steel had gained significant recognition in the ancient world.<ref name=":0">Vibha Tripathi,  ''Aspects of Iron Technology in India'' in Propagation, vol 3-1, 2012</ref> India abounded with vast deposits of many minerals and precious stones, thus [[Mineralogy (धातुशास्त्रम्)|mineralogy]] was an important topic dealt with even in texts such as Rigveda that helped develop and sustain many metal and alloy industries. 

== Introduction ==

== Introduction ==

The precise manner in which man discovered iron is unknown and may have been accidental. Man must have come to know of iron through meteorites; they contain high percentage of nickel and is difficult to forge. The earliest recorded instances of the use of meteoric iron are from Egypt and Mesopotamia. It is more likely that iron was first found in ashes of a fire set up by chance near the outcrop of an iron rich mineral. A folklore of the `Bastar tribe of central India states that their forefathers first made iron accidentally in a hollow anthill. Meteoric iron did not offer scope for any techniques involved in iron working such as smelting and forging and thus may have hardly played any role in the development of Iron age. The intentional heating of iron mineral with charcoal and development of smelting process heralded the beginning of iron making and subsequently its fabrication into implements and weapons marks the emergence of iron age.<ref name=":1">A. K., Vaish, Biswas P. K., Goswami N. G., Krishnan C. S. S., and Ramachandra Rao P. “Historical Perspective of Iron in Ancient India.” ''Journal of Metallurgy and Materials Science'' 42, no. 1 (January 2000): 65–74.</ref>

The precise manner in which man discovered iron is unknown and may have been accidental. Man must have come to know of iron through '''meteorites'''; they contain high percentage of nickel and is difficult to forge. The earliest recorded instances of the use of meteoric iron are from Egypt and Mesopotamia. It is more likely that iron was first found in ashes of a fire set up by chance near the outcrop of an iron rich mineral. A '''folklore of the `Bastar''' tribe of central India states that their forefathers first made iron accidentally in a hollow anthill. Meteoric iron did not offer scope for any techniques involved in iron working such as smelting and forging and thus may have hardly played any role in the development of Iron age. The intentional heating of iron mineral with charcoal and development of smelting process heralded the beginning of iron making and subsequently its fabrication into implements and weapons marks the emergence of iron age.<ref name=":1">A. K., Vaish, Biswas P. K., Goswami N. G., Krishnan C. S. S., and Ramachandra Rao P. “Historical Perspective of Iron in Ancient India.” ''Journal of Metallurgy and Materials Science'' 42, no. 1 (January 2000): 65–74.</ref>

Greek historian, Herodotus, stated in his book that Indian soldiers fought with iron-tipped arrowheads in their battles. There are records stating that swords of Indian steel were gifted as a tribute to monarchs emphasizing their valuable nature and they were exported to different parts of the ancient world.<ref name=":0" /> In India, D.K. Chakrabarti states that Iron has entered as a productive system by 800 B.C. Many areas from Central and Southern India, show evidence of Iron ore and Iron smelting indicating the earliest use of Indian iron in India. The iron and steel produced in early days was also shaped into useful articles. The primacy of iron technology in the Indian subcontinent is well established and there are several published books<ref>''Bag, A. K (1997) ed., History of Technology in India, Vol. 1, From Antiquity to c. 1200 A.D. by A. K. Bag.'' New Delhi: Indian National Science Academy.</ref><ref>Bose, D. M, et al., (1971) ed., ''A Concise History of Science in India''. New Delhi: Indian National Science Academy</ref><ref>Rao, Ramachandra P. and Goswami, N.G. (2001) ''Metallurgy in India: A Retrospective'' New York: India International Publisher</ref> and articles on the state of ancient Indian iron technology. Sushruta, the medical science expert in ancient India described many surgical instruments in his book [[Sushruta Samhita (सुश्रुतसंहिता)|Sushruta Samhita]] (third or fourth century BCE).<ref>Iron and Steel Industry in Ancient India by Satyendra</ref>

Greek historian, Herodotus, stated in his book that Indian soldiers fought with '''iron-tipped arrowheads''' in their battles. There are records stating that swords of '''Indian steel were gifted as a tribute to monarchs''' emphasizing their valuable nature and they were exported to different parts of the ancient world.<ref name=":0" /> In India, D.K. Chakrabarti states that Iron has entered as a productive system by 800 B.C. Many areas from Central and Southern India, show evidence of Iron ore and Iron smelting indicating the earliest use of Indian iron in India. The iron and steel produced in early days was also shaped into useful articles. The primacy of iron technology in the Indian subcontinent is well established and there are several published books<ref>Bag, A. K (1997) ed., ''History of Technology in India, Vol. 1, From Antiquity to c. 1200 A.D.'' New Delhi: Indian National Science Academy.</ref><ref>Bose, D. M, et al., (1971) ed., ''A Concise History of Science in India''. New Delhi: Indian National Science Academy</ref><ref>Rao, Ramachandra P. and Goswami, N.G. (2001) ''Metallurgy in India: A Retrospective'' New York: India International Publisher</ref> and articles on the state of ancient Indian iron technology. Sushruta, the medical science expert in ancient India described many surgical instruments in his book [[Sushruta Samhita (सुश्रुतसंहिता)|Sushruta Samhita]] (third or fourth century BCE).<ref>Iron and Steel Industry in Ancient India by Satyendra</ref> The present article includes the chronology of time as stated in particular authors mentioned in the references in some instances and are not the views of the author of this writeup.

== Historical evidence of Iron in Ancient India ==

== Does Ayas mean a metal or iron? ==

The history of iron can be traced back based on the historical and archaeological sources including modern radiocarbon dating. The early hymns of Rig-Veda written about 2000 B.C., revealed the knowledge of extracting metals from ores. 'AYAS' (iron) was the third Rig-Vedic metal after gold and silver. The Yajur Veda also has the mention of iron in the famous Rudra adhyaya. <blockquote>अश्मा च मे मृत्तिका च मे गिरयश् च मे पर्वताश् च मे सिकताश् च मे वनस्पतयश् च मे हिरण्यं च मे ऽयश् च मे श्यामं च मे लोहं च मे सीसं च मे त्रपु च मे यज्ञेन कल्पन्ताम् ॥ (Yaju. Samh. )<ref>[https://sa.wikisource.org/wiki/%E0%A4%B6%E0%A5%81%E0%A4%95%E0%A5%8D%E0%A4%B2%E0%A4%AF%E0%A4%9C%E0%A5%81%E0%A4%B0%E0%A5%8D%E0%A4%B5%E0%A5%87%E0%A4%A6%E0%A4%83/%E0%A4%85%E0%A4%A7%E0%A5%8D%E0%A4%AF%E0%A4%BE%E0%A4%AF%E0%A4%83_%E0%A5%A7%E0%A5%AE Shukla Yajurveda] </ref>  

The history of iron can be traced back based on the historical and archaeological sources including modern radiocarbon dating. The early hymns of Rigveda revealed the knowledge of extracting metals from ores. 'AYAS' (iron) was the third Rig-Vedic metal (after gold and silver) according to some scholars<ref name=":1" /> while others, Lallanji Gopal, Tripathi<ref name=":0" /> argued that it stood for metal in general in Rigveda. Yajurveda mentions gold, silver, copper, lead, tin and iron in the famous Rudra adhyaya. The terms 'krishna or shyamaayas' (the black metal) and lohitayas (the red metal) denoting iron and copper, respectively were coined in the Shukla Yaurveda (28.13) text.<ref name=":0" /> <blockquote>अश्मा च मे मृत्तिका च मे गिरयश् च मे पर्वताश् च मे सिकताश् च मे वनस्पतयश् च मे हिरण्यं च मे ऽयश् च मे श्यामं च मे लोहं च मे सीसं च मे त्रपु च मे यज्ञेन कल्पन्ताम् ॥ (Yaju. Samh. )<ref>[https://sa.wikisource.org/wiki/%E0%A4%B6%E0%A5%81%E0%A4%95%E0%A5%8D%E0%A4%B2%E0%A4%AF%E0%A4%9C%E0%A5%81%E0%A4%B0%E0%A5%8D%E0%A4%B5%E0%A5%87%E0%A4%A6%E0%A4%83/%E0%A4%85%E0%A4%A7%E0%A5%8D%E0%A4%AF%E0%A4%BE%E0%A4%AF%E0%A4%83_%E0%A5%A7%E0%A5%AE Shukla Yajurveda] </ref>  

aśmā ca me mṛttikā ca me girayaś ca me parvatāś ca me sikatāś ca me vanaspatayaś ca me hiraṇyaṃ ca me ’yaś ca me śyāmaṃ ca me lohaṃ ca me sīsaṃ ca me trapu ca me yajñena kalpantām || </blockquote>Rig-Vedic hymns have reference to the soldiers putting on '''coats of mail''' (a jacket covered with or composed of metal rings or plates, serving as armour) and using '''metallic helmets'''. Ancient Indians deployed the use of iron in '''agriculture and warfare'''. The uses of iron extended down to southern tip of Tamil Nadu. Based on the weapons and implements cited in Rig-Veda and the puranas, iron making technology existed to fulfill man's needs for war and peace.<ref name=":1" />

aśmā ca me mṛttikā ca me girayaś ca me parvatāś ca me sikatāś ca me vanaspatayaś ca me hiraṇyaṃ ca me ’yaś ca me śyāmaṃ ca me lohaṃ ca me sīsaṃ ca me trapu ca me yajñena kalpantām || </blockquote>However, according to A. K. Vaish, et. al.<ref name=":1" /> Rig-Vedic hymns have reference to the soldiers putting on '''coats of mail''' (a jacket covered with or composed of metal rings or plates, serving as armour) and using '''metallic helmets'''. Ancient Indians deployed the use of iron in '''agriculture and warfare'''. The uses of iron extended down to southern tip of Tamil Nadu. Based on the weapons and implements cited in Rig-Veda and the puranas, iron making technology existed to fulfill man's needs for war and peace.<ref name=":1" />

Rapid developments in iron making and its use took place around 1400 B.C. The history of early iron smelting, practiced by the tribal artisans in different regions of ancient India dates back to 1300 to 1200 B.C. The use of iron was relatively unknown except in areas where iron bearing minerals were abundant. Prakash and Tripathi<ref>Prakash, B., and Tripathi, V., (1986), ''Iron technology in ancient india,'' In Historical Metallurgy, September, pp. 568-579.</ref> have documented the early iron age cultures, which could have been independent of each other, arising in five different zones of India. These five cultures were  

Rapid developments in iron making and its use took place around 1400 B.C. The history of early iron smelting, practiced by the tribal artisans in different regions of ancient India dates back to 1300 to 1200 B.C. The use of iron was relatively unknown except in areas where iron bearing minerals were abundant. Prakash and Tripathi<ref>Prakash, B., and Tripathi, V., (1986), ''Iron technology in ancient india,'' In Historical Metallurgy, September, pp. 568-579.</ref> have documented the early iron age cultures, which could have been independent of each other, arising in five different zones of India. These five cultures were  

[[File:Iron Smelting Furnace.PNG|thumb|Megalithic iron smelting furnace at Naikund (near Nagpur, Maharashtra)]]

[[File:Iron Smelting Furnace.PNG|thumb|Megalithic iron smelting furnace at Naikund (near Nagpur, Maharashtra)|314x314px]]

(i) Cairn Burial culture in northwestern India  

(i) Cairn Burial culture in northwestern India  

=== Archeological Excavations ===

=== Archeological Excavations ===

[[File:Table of Iron Tools and Implements.png|right|frameless|519x519px]]

[[File:Table of Iron Tools and Implements.png|right|frameless|519x519px]]

The following are a few iron artifacts excavated and investigated in Indian Archeological sites.<ref name=":1" />  

The following are a few iron artifacts excavated and investigated in Indian archeological sites.<ref name=":1" />  

* A large number of '''iron implements''' have been unearthed at Adittanallur, Tamilnadu at a burial site which is dated to around 250 B.C. A table of various iron tools and implements appearing at the three stages of iron technology in ancient India has been provided below.  

* A large number of '''iron implements''' have been unearthed at Adittanallur, Tamilnadu at a burial site which is dated to around 250 B.C. A table of various iron tools and implements appearing at the three stages of iron technology in ancient India has been provided below.  

* '''Iron implements''' comprising of agricultural implements, blacksmith tools etc., have been unearthed at Taxila (3-5 B.C.) Besides numerous ingots of iron, iron spearheads, spikes and nails belonging to the second century A.D. have been found in UP, near Basti and Kapilvastu.

* '''Iron implements''' comprising of agricultural implements, blacksmith tools etc., have been unearthed at Taxila. Besides numerous ingots of iron, iron spearheads, spikes and nails belonging to the second century A.D. have been found in UP, near Basti and Kapilvastu.

* The great battle of `Kurukshetra' was fought (probably around ninth century B.C.) which witnessed the extensive use of '''iron weapons and armour'''.

* The great battle of `Kurukshetra' was fought which witnessed the extensive use of '''iron weapons and armour'''.

* Sushruta, the great surgeon of ancient India indicated that even in the early period, Hindus had learnt the art of manipulating the '''lancet''' and handled the '''simple surgical instruments made of iron and steel'''.

* Sushruta, the great surgeon of ancient India indicated that even in the early period, Hindus had learnt the art of manipulating the '''lancet''' and handled the '''simple surgical instruments made of iron and steel'''.

* At Pandu Rajar Dhibi in West Bengal use of iron has been traced to first millennium B.C.

* At Pandu Rajar Dhibi in West Bengal use of iron has been traced to first millennium B.C.

* In the J'''agannath temple of Puri''' in Orissa, built in the 12th century A.D. '''239 iron beams''' have been used.

* In the J'''agannath temple of Puri''' in Orissa, built in the 12th century A.D. '''239 iron beams''' have been used.

* The '''iron trident in Tanginath temple''' belongs to 12th century A.D.

* The '''iron trident in Tanginath temple''' belongs to 12th century A.D.

* Babar used guns in first battle of Panipath in 1526 A.D. Guns were introduced in southern India by the Portuguese. Most Mughal guns were generally constructed of iron bars of square section.

* Babar used guns in first battle of Panipath in 1526 A.D. '''Guns''' were introduced in southern India by the Portuguese. Most Mughal guns were generally constructed of iron bars of square section.

 

 

*  

*  

== Quality of Iron in Ancient India ==

== Pyrometallurgy ==

The iron produced in the indigenous furnaces was wrought iron. It contained low percent-age of carbon due the lower absorption of carbon in ancient iron making furnaces. Steel was produced by carburization of wrought iron during this period. It is said that India is the first producer of carbon steel (wootz). In fact, India was considered to be the centre of origin of iron and steel industry in the world. It is possible that iron age in India had started about 3000 years before the industry started in European countries. The '''Damascus swords''' which became famous in Europe were made from Indian wootz. In those days, Hyderabad and Madras in South India were the centres of production of wootz. The process of wootz making was specially popular in the districts of Salem and Tiruchirappalli in Madras, besides the Hyderabad area, in Andhra Pradesh and Mysore. The ancient Indian steel was highly priced in world market. The possibility of a country wide manufacture of iron existing from quite early times, is also indicated by the references to the working of iron mines in Bajuha, Subha Bengal, Keroh, Subha Kashmir, Kumaon, Khasi Hills, Subha Delhi, besides at Nirmal and Indore in Ain-i-Akbari.

The extraction of iron is pyrometallurgy. It is the extractive metallurgy which consists of the thermal treatment given to minerals or ores to recover the metal. The process involves chemical reactions at elevated temperature.  The process of extraction of iron is fundamentally very simple as it consists essentially of the reduction of iron oxide by carbon. But as molten iron dissolves carbon and other impurities, iron obtained is impure and is known as pig iron or cast iron. The ore (red haematite or hydrated oxide or carbonate) is calcined in shallow kilns to remove moisture, carbon dioxide etc. The ore thereby becomes porous and is then more easily reduced in the blast furnace.<ref>[https://prog.lmu.edu.ng/colleges_CMS/document/books/MCE329%20-%20Metallurgy%20of%20Iron(329).pdf Metallurgy of Iron] </ref>

 

 

* Spathic Iron ore or Siderite - FeCO₃ (Carbonate ore) is rarely used.  

 

Iron is normally extracted from its oxide ore called haematite and is rarely extracted from carbonate ore called siderite. Iron pyrite is an important source of sulphur and therefore it is not used in the extraction of iron.

 

The overall reaction for the production of iron in a blast furnace is as follows:

 

 

Where Fe₂O₃(s) stands for Hematite ore (Ferrous Oxide, s = solid), C stands for Carbon (in the form of solid coke), Δ represents the energy requirement for the reaction to take place, Fe stands for Ferrum (elemental Iron, l = liquid) and CO stands for Carbon monoxide (g = gaseous state)

 

Iron compounds in the ores could be reduced by carbon; and for a long time, charcoal was the form of carbon used in the reduction process. Charcoal was replaced by Coke, a form of carbon formed by heating coal in the absence of air to remove impurities, improving the reduction process. As seen in the equation above, the actual reductant is CO, which reduces Fe₂O₃ to give Fe(l) and CO₂(g).

 

[[File:Blast furnace .png|right|frameless|325x325px|Blast Furnace for Converting Iron Oxides to Iron Metal. Courtesy: General Chemistry (Libre Texts)]]

The extraction of iron involves following steps.

 

 

Iron ores were widely distributed in Indian subcontinent. However they were delayed to smelt Iron. The reason is that the primitive condition of furnace has produced temperature about 1100°C which is required for Copper smelting. But Iron needs a high temperature almost above 1500°C for the ore to smelt into a liquid. Little solid grains of Iron have obtained by low temperature as 800°C. Iron was a soft and spongy material which had to be admixed with carbon in proper proportion to obtain sufficient sharpness and hardness. It was obtained from ores at high temperature. Iron has more impurties than Copper. This impurity has to be removed by using a catalytic flux such as lime to produce the slag (Rao 1970:258). Iron produced by smelting is divided into 3 kinds:

 

 

Quenching and tempering was also learned along with steeling of Iron. Quenching consists immersing the red hot metal into water. Metal would become harden by this process. Tempering consists of repeated heating of the metal and allowing it to cool slowly while it is hammered (Banerjee 1965:2).<ref>Saravanan, R. ''Iron:'' ''From Metal to Metallurgy'' Heritage: Journal of Multidisciplinary Studies in Archaeology 5 (2017): 514‐518</ref>

== References ==

== References ==

[[Category:Shastras]]

[[Category:Shastras]]