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Minerals and Metals in Ancient India v1.c18: 10. Copper in Ancient India

Minerals and Metals in Ancient India v1.c18

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10. Copper in Ancient India

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In the previous chapters we have recorded different aspects of material civilizations as found in the chalcolithic cultures of India. Before we proceed to discuss the Iron Age in the sub-continent, we may summarise and critically evaluate the different aspects of the use of copper in ancient India, which of course continued in the Iron Age.

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There is no necessity to repeat what we have already recorded (in the previous nine chapters) on copper in India. In this chapter we would focus our attention on specific issues of crucial importance:

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(a) Were the earliest artefacts made of native or smelted copper?

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(b) Was the Harappan copper technology imported or indigenously developed?

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(c) The issue of artefact-ore correlation.

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(d) Special studies on the ancient copper mining and metallurgy in Rajasthan.

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(e) The three nuclear zones of chalcolithic traditions — Harappan in the north-west, chalcolithic culture in Peninsular India and Copper Hoard Culture in the east; were they absolutely unrelated?

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(f) Copper in the Historical Period of India.

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(g) Ancient mines of copper in the Pre-Historical and Historical Periods of India, and lastly, (h) Some outstanding copper artefacts in the Iron Age of India.

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We would like to discuss the issues one by one and in the order stated above.

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Like gold and silver, copper also occurs in the metallic state in nature, and it is possible that native copper was used first in human civilization prior to the discovery of the art of smelting the metal from its oxide, carbonate and sulphide minerals. Native copper could be used to manufacture artefacts by one of the three ways: cold hammering, periodic annealing using heat and by melting and solidification which changes the grain orientation.

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Maddin et al. (1980) concluded that no adequate criteria exist for distinguishing artefacts of native copper from those of worked and recrystallized smelted copper of high purity. The seventh millennium BC copper artefacts in Cayönü in south-eastern Turkey and in Mehrgarh of the Indian sub-continent arose in the aceramic context and therefore could be native copper.

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In chapter 2, we have reported Jarrige’s discovery of the seventh to fifth millennium BC copper artefacts from Mehrgarh. Around 4000 BC, smelting of copper was well-known at Mehrgarh as well as in Tal-i-Iblis in Mashiz Valley of Iran. (Caldwell, 1967) When D.P. Agrawal precluded independent origin of copper metallurgy in India and conceded that the metallurgical know-how had diffused to India of the Harappan era from Iran (Agrawal, 1971: 232 and 239), Jarrige’s discovery of Mehrgarh (1979) was yet to be made. Now we may propose that the impetus to the copper metallurgical practices in the Harappan civilization came from within the Indian sub-continent and the Indo-Iranian borderlands.

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Apart from the Mehrgarh area in Baluchistan which had substantial reserves of copper ore, Ganeshwar area in Rajasthan exhibited pre-Harappan traditions in copper smelting practices which have been discussed in chapter 2. Asthana has rightly concluded (1985) that “the Indus civilization was conceived locally in the courtyard of one or more of the Pre-Harappan cultures”. This remark is applicable to the Harappan art of copper-smelting as well.

Artefact-Ore Correlation

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In pursuing the laudable objective of establishing that the metals were produced indigenously in the ancient India, our archaeologists have sought correlation between the artefacts and ores in the sub-continent.

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Most of the enthusiastic investigators ignored the cautionary remarks of Thomson (1958) pointing out the hazards in ore-correlations, and reported ‘positive correlation’s which may not be considered to be conclusive. Recently Biswas (1990) has pointed out that the ore-metal correlation depends upon:

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(a) the type of ore, oxide of sulphide or silicate, the nature of impurities, (b) the precise conditions of smelting, such as temperature, nature of fuel, flux etc., and several other factors. The ore-type itself is a variable even within a single mine.

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A ‘correlation’ can only be probabilistic. A positive correlation of the trace element profile between ore and metal cannot be accepted as sufficient or conclusive evidence for indigenous manufacture. On the other hand, lack of correlation does not construe necessarily a negative evidence. As we have said, ore types vary even within a region of hundred square kilometres.* Besides, certain impurities such as arsenic might have been eliminated through certain simple pre-smelting operations such as roasting.

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So far as the use of metals in the ancient sites are concerned, the existence or absence of mines in the neighbourhood areas in the modern age hardly establishes any truth. On the one hand, the currently known mines might have been unknown to the ancient people, and on the other, some small near-surface reserves might have been thoroughly exploited by the ancient miners, so that we do not know them at present.

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Having stated the hazards of ore-metal correlation, let us report some of the ‘positive correlations’ obtained by our archaeo-metallurgists. Friedman *et al.* (1966) claimed that with regard to copper artefacts, the elements of silver, arsenic, bismuth, iron, antimony and lead were the most important metallic impurities in relating the metal back to the original type of ore. Following this argument, Agrawal (1971, 1984) suggested that Chanhu-Daro celt and Mohenjo-Daro spearhead were made from Khetri chalcopyrite ore, since all the three materials contained trace impurities of Sb, Pb but not Fe and As.

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In chapter 7, we have mentioned that Hegde (1969) compared the artefacts from Ahar with the chalcopyrite ore from Khetri, and the similarities led him to conclude that “copper metal of the Ahar artefacts was probably smelted from the ore of the Aravalli region”. While the conclusion can certainly be supported from other evidences such as slag dumps and ancient mines, Hegde’s argument is hazardous. ‘The Aravalli region’ alluded to by Hegde corresponds to a vast area and ores of more than one type; the Ahar region is hundreds of kilometres away from Khetri.

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Hegde (1989) has himself modified his view and suggested that the Ahar artefacts were possibly made from the nearby region of the Aravalli which constitutes of not-too-hard tremolite-chlorite schists rather than the far-off Khetri ore embedded in quartzite rocks, hard and less easily extractable. While impurity patterns of the ores in different parts of the Aravalli may be similar, the lead isotope ratios markedly differ in the north-eastern, central, and south-western parts of Aravalli. (Hegde, 1985) Efforts are in progress to correlate metal artefacts and specific ore deposits through lead isotope ratio analysis.

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∗ Hegde failed to detect the impurity elements of Cr, Co, Ni, Bi and Mo (present in the Devnimori silver coin) in the Zawar galena ore, but Shekar found them in the Ambamata deposit only a hundred km away (vide our Table 17.7). Silver did not have to be ‘imported’!

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S.R. Rao (1979, 1985) considered the facts that whereas Mohenjo-Daro copper and Rajasthan ore contain arsenic, the copper artefacts from Lothal were remarkably arsenic-free. From these facts divergent inferences could be drawn: Mohenjo-Daro people obtained copper from Rajasthan or from some other source and resorted to deliberate arsenic-alloying (which they did in some instances). Lothal copper might have been imported from Oman (as suggested by S.R. Rao), or the Lothal technicians practised, like the Aharians, roasting of copper ore to make it arsenic-free. Evidently, these conclusions are not compatible with each other. Rao himself reported the analysis of a copper ore from Rajasthan which contained negligible quantity of arsenic. Thus it is hazardous to draw any positive correlation between the artefacts and any ore-deposit.

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H.C. Bhardwaj (1979: 97) found that Rajghat copper artefacts (600 BC) and Bihar ore show the presence of Fe, S, Ag, Ni, Co, Mo, Bi, Ca, Mg, Al and Si. Frequency of Pb, As, Sb is less in both Rajghat samples as well as Bihar ores compared to Khetri ore. From the point of view of proximity, it is quite possible that Rajghat copper was made from Bihar ore, but the question still remains: from which part of Bihar?

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For conclusive evidences on indigenous technology in the areas of minerals and metals, we should better look for: (a) mines of antiquity, (b) outfits for smelting, furnaces and crucibles, (c) heaps of slags and slag-ore correlation regarding the non-metallic phases, and (d) a reasonably large number of artefacts at different stages of manufacture and of composition and properties varying within narrow limits. Fortunately, several such evidences for indigenous metallurgy in India have been obtained from Mehrgarh, Ganeshwar-Jodhpura, Chanhu-Daro, Lothal, Ahar, Khetri (for copper), Atrañjikhera, Ujjain (iron), Zawar (zinc) etc.

Ancient Copper Mines and Metallurgy in Rajasthan

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Hegde *et al.* (1985) carried out a survey of six ancient copper ore mining and smelting sites in the Aravalli Hills extending over a thousand kilometres: Khetri and Kho Dariba in the north-eastern part, Kankaria and Piplawas in the central part, and Deri and Ambaji in the south-western part. Ambaji was studied in detail.

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In the south-western and central zones, there were many evidences of superficial gouging of the oxide-rich gossan cap; these were the earliest attempts at mining copper ore in Rajasthan. A large majority of these pits measure 7-8 metres in diameter and three to four metres in depth. There is evidence of fire-treating of the host rocks on the mine walls to widen the rock joints.

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In all the six sites visited, the investigators noticed (Hegde *et al.* 1985) mine shafts which were very deep, opening into galleries and narrow tunnels following the natural configuration of ore veins at different levels. There were ventilation holes at regular intervals. These deep shafts probably represented mining activity of later periods; however, there are evidences to believe that some of the mines were worked during the Chalcolithic period. Timber supports recovered from a gallery at a depth 120 metres at Rajpura-Dariba mines in Udaipur District were dated by radiocarbon to 3120 ± 160 years before the present (1987). This date corresponds to the zinc-containing copper artefacts of Atrañjikhera. There are some Mauryan C-14 dates such as 2310 ± 105 B.P. from the Dariba Mines area also.

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The small size of furnace and high yield of metal indicate that the ore used to be roasted to oxide stage and the smelting technology was efficient. Many groups of ore-crushing pits were found near the foot of the hills. Larger pits among them measure 60 cm in diameter and 70 cm in depth. Smaller ones measure 30 cm in diameter and 40 cm in depth. The finely crushed ore was concentrated by gravity separation at the smelting sites which were invariably located near the banks of the hill streams. Ore separation devices found are smooth gently inclined rock surfaces, nearly marked with rows of round shallow pits, 3 to 4 cm in diameter and 3 to 4 cm depth. Presumably, the finely crushed ore was allowed to slowly flow down the inclined plane and by repeating this process, much of the gangue was effectively separated from the ore. Flowing film segregation, settling of the heavier ore particles in the pits and elutriation of the lighter gangue particles were the principles involved.

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The smelting charge probably constituted of crushed quartz, about equal weight of the ore, and crushed charcoal, nearly twice the weight of the ore. Residues of small, hand-made, fistfulls of spherical lumps were found sticking to the furnace walls. Coarse size of the feed lumps enabled easy flow of air coming from the bellows.

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Large slag heaps were found spread out in the terraces, littered with broken remains of furnaces and broken tuyere. Some of the slag pieces clearly revealed the cylindrical flow structure and the fact that the tapped slag was molten.

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The examination of the unbroken upper part of the furnace showed that this was assembled by putting three curved segments (made of clay) together, one of them containing the luted tuyere, another with the slag tapping hole, and a plain third one. The bottom part of the furnace was not found, and this was conceptualized using the size and shape of the copper ingots or buns recovered in the excavations of the Chalcolithic sites of Lothal, Harappa and Mohenjo-Daro. The Lothal bun is smoothly curved at the bottom (corresponding to the bottom part of the furnace), 10 cm in diameter, 4 cm in height and weights 1.438 kg. (Rao 1979 and 1985) On the basis of the above data, Hegde et al. (1985) visualised the approximate dimensions of the ancient furnace : 35 cm in height, and diameter 18 cm at the rim, 14 cm at a mid-level and 10 cm near the base. (fig. 10.1)

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Thus, it appears that the ancient Indian copper smelting furnace was a small, crucible-shaped, clay-walled, slag-tapping furnace worked on forced draught blown into it from bellows. It was a composite structure made of three moulded segments, set up on a brick platform and was surrounded with bricks and earth to keep the three segments of the furnace tightly in position and also to conserve the heat within the furnace.

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The main component of the slag is fayalite which melts at 1170°C. The melting point of copper is 1083°C. Molten copper of high specific gravity 8.89 collected below the molten slag of the 4.0 sp. gr. The molten slag was evidently tapped on the edge of the terrace. When the furnace was cooled, the copper ingot was taken out by breaking its bottom. Hegde et al. (1985) may be right when they comment that “this simple furnace appears to have been continuously used in India over the millennia without little innovation”.

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In the previous chapters we have mentioned the discoveries of small furnaces and crucibles in the Harappan and Chalcolithic sites. The facilities near the settlements, far away from mining regions, were mostly purification and fabrication facilities and not primary smelting outfits. Bun-shaped copper ingots used to be transported from the Ganeshwar area along the Sarasvati-Hakra riverine route and remelted, purified and fabricated near the Harappan metropolis. There must have been itinerant metal-smiths in the copper-hoard culture carrying ingots over considerable distances and fabricating them anew to suit the specifications of the customers. The *Rg Veda* (9.112.2) refers to such itinerant metal-smiths.

Three Ancient Indian Traditions in Copper Metallurgy

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In the earlier chapters, we have discussed the three traditions in copper metallurgy: (a) Harappan, (b) Chalcolithic in the Peninsular India, and Fig. 10.1: Ancient Copper-making Furnace at Ambaji, Rajasthan.

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THREE MOULDED TERRACOTTA SEGMENTS OF THE FURNACE

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ASSEMBLED FURNACE

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(c) Copper Hoard in the Eastern India. D.P. Agrawal (1971, 1982, 1984) considers that these three traditions were entirely different. We however feel that there might have been certain meeting grounds.

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The Harappans were rich in copper usage, and were the only people in ancient India to use copper vessels apart from axes and swords. The vessels were made in two parts and joined together by running on and rivetting techniques. (Soldering was used only for noble metals). Metallographic examination shows that the Harappans resorted to open and closed casting, slow cooling of casting, annealing and cold work. (Agrawal, 1971, 1982) Small animal and female figurines like the famous 11 cm high dancing girl statuette were cast by the cire perdue (lost wax) process. A number of axes from Chanhu-Daro and Mohenjo-Daro show pucked surfaces and blow holes, indicating that ‘green poling’ was not done in open moulds to remove oxygen. True saws with teeth and body set alternatively from side to side appear at Mohenjo-Daro, perhaps for the first time in the world.

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Agrawal et al. (1978) reported that Copper Hoard artefacts were not unalloyed as scholars earlier believed. 33 samples from Hami, Bahadurabad, Narsipur, Sadabad, Shahabad and nine other sites were characterised by substantial arsenic alloying. Assay figures showed up to 7.844 per cent, as in a copper celt from Hami. Lead was also used for alloying. In the Harappan artefacts (200 examined), tin was the major alloying element; white 70 per cent artefacts were unalloyed, 10 per cent samples contained 1-7 per cent tin, another 14 per cent assayed 8-12 per cent tin and the remaining 6 per cent assayed 12 per cent of tin. Of the 200 samples examined, only 12 per cent were alloyed with As and 8 per cent with lead. Thus there were less number of samples alloyed with As, and even less number alloyed with Pb. On the other hand, Chalcolithic Culture samples were alloyed more with Pb and Sn than As. Data presented in Table 10.1 show the clear contrast between the three traditions.

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In the West Asian regions, arsenic alloying preceded tin alloying which made a beginning in Iran only during the third millennium BC. On this basis, Agrawal (1978) wondered whether the Copper Hoard Culture started even earlier than the Harappan Culture. There are however no dates to confirm such an antecedance.

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At any rate, arsenical alloying was well-known in the Harappan culture; löllingite (FeAs₂) samples were found in Nal etc. Like tin, arsenic also increases the hardness of copper; however it might have been used as a deoxidiser also. Lead was probably used a flux. Out of 177 Harappan artefacts examined, 4 per cent contained some nickel (assay figure 1 to 9 per cent). Evidently the Harappan civilization produced a wide spectrum of copper artefacts on account of its vast coverage of time and space. This is illustrated in the artefacts from Rangpur, Gujarat a Post-Harappan (2000-1300 BC) site. Whereas Lothal artefacts do not contain much nickel, a copper celt from Rangpur contained as much as 2.10 per cent nickel and a copper pin 5.88 per cent. Nickel in these samples was probably derived from the Rupavati ore in the neighbourhood and not an intentional addition.

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While the three cultures had distinct differences, there might have been some points of contact and even influence. The Chalcolithic Culture (2000-900 BC) had three phases — Kayatha, Malwa and Jorwe; the first phase was probably initiated by some Pre-Harappans like Sothians and Post-Harappans like Aharians. Cast axes from Kayatha are the most beautiful examples of Chalcolithic craft. Navdatolians knew casting and annealing, and their craft excelled that of Aharians. The superb craftsmanship of Daimabad bronzes suggests the link between the Post-Harappan metal-smiths of Gujarat with the southern chalcolithic cultures, which however could not imbibe the Harappan technology of making copper pots and vessels.

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S.R. Rao (1973: 183-84) suggested ‘the diffusion of Harappan technology’ from Kathiawar and Narmada Valley towards the east and the south, and commented:

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The fact that bar-celts and chisels and flat rectangular axes (celts) were as popular in the Copper Hoard and the Indus Valley Cultures should not be overlooked. By 1900 BC the Harappans had already evolved at Lothal the crescentic sleeved axe which is associated with the Copper Hoard people and resembles the Bisauli anthropomorphic figure. (Rao, 1973: 183-84)

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Evidently, Rao differed from Agrawal and Bhardwaj (1970) who did not find any technological resembles among the three early copper and bronze technologies. We may mention certain additional points supporting Rao’s view.

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Similar pure copper artefacts were found at Mitathal in the successive levels of Sothi, Harappan and Copper Hoard Culture occupations. We know that Sothians initiated Chalcolithic Culture at Kayatha which spread towards the Peninsular India. And lastly, it is quite likely that the lead-alloying tradition of the Peninsular Chalcolithic Culture was transmitted to the Copper Hoard Culture at Gungeria (of the Balaghat District, Madhya Pradesh), which yielded 400 kg of copper hoard assaying 1.5 per cent lead. Apart from the 424 implements such as celts, shovels, axe-blades, spades etc. of copper, Gungeria also yielded 102 pieces of thin silver plates weighing about one kg and assaying 96 per cent silver and 3.7 per cent gold. (Neogi, 1917, 1979: 12-13) It may be proposed that Alloying Pattern in the Copper Artefacts of the Harappan, Chalcolithic and Copper Hoard Cultures

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| Culture | Total No. of artefacts | No. of Sn bearing artefacts | % of Sn bearing artefacts | No. of As bearing artefacts | % of As bearing artefacts | No. of Pb bearing artefacts | % of Pb bearing artefacts |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Harappan | 219 | 50 | 22.83 | 26 | 11.87 | 17 | 7.76 |
| Chalcolithic | 29 | 5 | 17.24 | 0 | 0 | 6 | 20.6 |
| Copper Hoard | 33 | 0 | 0 | 15 | 45.45 | 1 | 3.0 |

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| Culture | Total No. of artefacts | No. of Sn+ As bearing artefacts | % of Sn+ As bearing artefacts | No. of Sn+ Pb bearing artefacts | % of Sn+ Pb bearing artefacts | No. of As+ Pb bearing artefacts | % of As+ Pb bearing artefacts |
| | | 9 | 10 | 11 | 12 | 13 | 14 |
| Harappan | 219 | 9 | 4.11 | 14 | 6.4 | 3 | 1.4 |
| Chalcolithic | 29 | 0 | 0 | 5 | 17.24 | 0 | 0 |
| Copper Hoard | 33 | 0 | 0 | 0 | 0 | 2 | 6.0 |

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lead, silver and gold originated from the argentiferous lead ore mines in Peninsular India, and copper came from Bihar.

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Characterised chiefly by the antennae sword, anthropomorph and the harpoon, the Copper Hoard Culture also produced celts, axe-blades, socketed axes which ended up in Gungeria and the Uttar Pradesh/Bihar sites of the Historical Period. The exclusive occurrence of bar-celts in the eastern region may indicate their use for crowbar-like operations in mining in the Bihar area which supplied the raw material for copper. The Copper Hoard people knew the closed casting method like the Harappans. Many artefacts were made by cutting metal sheets and hammering. Metallographic examination of a few lead-alloyed specimens showed evidences of slow cooling, cold work and annealing; these techniques might have been acquired from the Chalcolithic Culture.

Copper in the Historical Period

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The silver sheets of Gungeria make one wonder whether the Gungeria culture had some link with the *Mahājanapada* tradition and the early Historical period, when punch-marked coins were introduced and the copper plates used to be made for inscriptions and land donations. One of the earliest copper plates is the Sohagura copper alloy plate from Gorakhpur district in the Uttar Pradesh in which the Mauryan inscription is in Brāhmī characters; this tradition continued in the post-Christian era. Bhardwaj (1979) analysed a piece of a copper sheet, obtained from Rajghat, Varanasi dated 600-400 BC, and found this to be 95.45 per cent copper, containing 1.75 per cent CaO, 0.96 per cent iron, 0.25 As, 0.15 Ni.

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The 600-400 BC Samples from Rajghat were made of unalloyed copper whereas 400-200 BC samples from the same site contained tin. A bronze fragment assayed 13.99 per cent tin, copper bangle 1.82 per cent, and an uninscribed rectangular coin 7.83 per cent tin. The impurity analyses of the artefacts and ore (the presence in both of Ni, Co, Mo, and very low frequency of Pb, As, Sb) suggested that the Rajghat copper artefacts were probably derived from Bihar ore. (Bhardwaj, 1979) It is apparent that during the Historical Period, the Harappan tradition of tin-alloying of copper was revived in the Eastern India; Kausa-mbi 500 BC bronze assayed 19.13 per cent tin, Sonepur Pd II bronze 32.42 per cent tin and so on. This was possible due to discovery and exploitation of the tin ore mines from the Hazaribagh area and/or some import of tin from Malayasia.

Some Ancient Copper Mines

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There is the likelihood that copper smelting started in the mining area of Singhbhum positively by the time of Copper Hoard Culture (1100-800 BC), and continued uninterrupted during the Historical Period. Bhardwaj (1979: 191-99) listed 19 ancient mines of Rajasthan, 11 of Uttar Pradesh and 12 of Bihar which include the famous Bara-gunda (= twelve pits) mine of Hazaribagh district having extensive old workings over a length of 1200 metres and slag heaps having 0.08 to 13.04 per cent copper, the Surda and Mosabani mines of Singhbhum district etc. Unfortunately, the organic residues in these ancient mines have not been preserved for C-14 bio-dating. (Kerr-Cross, 1950; Dunn, 1965)

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Some of the Indian copper ore mines with early C-14 datings are: Dariba (Rajpura) in Udaipur, Rajasthan, 1260 ± 160 BC continued up to 250 ± 100 BC, Ambamata (Banaskantha, Gujarat), 160 BC onwards to the post-Christian era, Bandlomattu Hill, (Guntur, Andhra Pradesh) AD 50 onwards to AD 1215, Ingaldahal (Chitradurga, Karnataka) AD 220 etc. (Chakrabarti, 1986: 188-96)

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S.R. Rao (1987) has suggested that Ingaldahal mining area supplied copper not only in the Historical era but also to the megalith-builders of the Chitradurga region around 500 BC, and even earlier around 1200 BC to produce Chalcolithic Period bronze artefacts of Brahmagiri which is not far away from Ingaldahal. Similarly, Kalyadi mine in Arsikere region of Karnataka has been claimed to have supplied copper ore to the megalith folk of the fifth century BC. Kallur copper swords (1200-1000 BC) were possibly made utilising the near-by copper oxide deposits. Thus, it is evident that the Peninsular Chalcolithic Culture and the Copper Hoard Culture, spreading to the Gaṅgā-Yamunā Doab, developed local copper mines to produce regional varieties of copper artefacts, till the Maurya era brought about a synthesis.

Copper Slag and Artefacts from Rājghāṭ

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Analysis of the Rājghāṭ copper slag showed that it was chiefly iron silicate with 5.39 per cent calcium oxide, whereas the Ahar slag did not contain any calcium oxide. Evidently, lime was used as a flux, a new innovation in India, and this is also shown in the CaO content (1-2.5 %) in the copper artefacts of Rajghat. (Bhardwaj, 1979) Presence of 1 per cent + copper oxide in the metallic phase shows that the molten copper was not properly ‘green poled’ or dexoidised.

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Metallographic examination showed that the copper sheet of Rājghāṭ had globular alternate banding of Cu-CuO eutectic. Annealing twins provided the evidence of heat-treatment having been done. Bronze coins had segregated Cu-rich Zone and Sn-rich grain boundary, proving that it was a cast structure. Very good coining and embossing were revealed in some Pre-Christian era Taxila coins which had glassy elongated slag streaks and fine equi-axed grains; these were evidently hot-worked, then cold-worked, and finally annealed. (Bhardwaj, 1979: 81)

The Use of Copper in the Iron Age of India

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The historical period in India is also associated with the increasing use of iron. Carburised iron was found to be cheaper and better than bronze in making weapons and agricultural implements. Naturally the use of copper was diverted towards the other purposes. We have already mentioned about Sohagura copper plate of the Maurya period. The Sue Vihar inscription of Kaniṣka (1st century AD) and the Taxila plates are also amongst the earliest of copper plates in India. Vincent Smith referred to a set of 31 sheets of copper used for writing copper inscriptions in South India. The tradition of inscribing on tāmrapatra (copper sheet) survived in India till the nineteenth century. Making copper wire had been an ancient tradition. Mitathal yielded a copper wire (98.57 per cent copper 1.13 per cent iron) from the Sothi-Harappan level. It is rectangular in cross-section and 2 mm in thickness. Taxila also produced wires for musical instruments. Copper and bronze mirrors were found in Taxila, Rairh, Basarh, Brahmapuri and many other sites corresponding to the period 200 BC-AD 200. (Margabandhu, 1974) From the Vedic references it is presumed that copper mirrors were produced and used even in the earlier eras.

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The earliest coins were punch-marked coins made of gold, silver and copper. In a number of silver punch-marked coins copper was used for alloying and debasing. Bhardwaj (1979: 140-42) mentioned that Caley had fixed the chronology of Pārthian kings, gradually increasing the copper content of silver coins, and proposed that a similar approach could be taken to establish the chronology of punch-marked coins in India. Kautilya’s Arthaśāstra recommended 11 parts of silver (68.75 % of the total), 4 parts of copper (25 %) and 1 part (6.25%) of any other base metal such as iron, tin, lead or antimony, for preparing silver coins. In some 400 BC punch-marked coins, the percentage of copper went up to 70-72 per cent and that of silver came down to 22-28 per cent. This clearly reflec-ted the growing shortage of silver in the country. Copper, though considered as less precious, was more abundant and freely used in making coins and various alloys.

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Utensils were made of copper and its alloys such as bell-metal, (later) brass etc. The Harappan tradition of making vessels, which was apparently lost or latent in the Chalcolithic and Copper Hoard Cultures, was revived during the ‘second’ (Historical) phase of urbanisation in India. Suśruta, Yājñavalkya, Manu etc. mentioned about the religious and ceremonial use of utensils made of copper and its alloys, and also the various recipes for cleaning them. Megasthenes mentioned that “vessels of Indian copper, set with precious stones, contributed to the brilliancy of the public ceremonies during Chandragupta’s region”. One remarkable ancient copper *loṭā* was found in 1857 in the village of Kundla in the Kangra district, Punjab; there was an inscribed scene running round it which represents Prince Siddhartha going in a royal procession in a chariot. The *loṭā* has been variously dated as belonging to first century BC or third century AD. Caskets for preservation of relics used to be made of copper and its alloys.

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Neogi (1917, 1979: 21-22) referred to the big solid copper bolt found in the Rāmpurwā Aśoka Pillar near the Nepalese border. It was evidently employed in fastening the colossal lion-shaped stone capital to the pillar itself. The bolt is barrel-shaped in appearance and slightly tapering at the two ends. It is 24-1/2 inches long, circumference at the centre being 14 inches and at the sides about 12 inches. Originally cast, this piece was ‘exquisitely worked into shape apparently with hammer, slight marks of which are still visible’.

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Swarna Kamal (1978) has reported a pure copper figure belonging to Gujarat and the pre-Gupta early centuries of the Christian era. This figure of fasting Śākyamuni in meditative posture is of solid cast having a height of 18 cms and width of 13 cms at the basal end. The metal consists of highly pure copper (99 %) with silicon (0.52 %) and iron (0.36 %) as the only two major impurities. Absence of sulphur and copper oxide in the metal led Swarna Kamal to postulate that this was made of native copper as in Taxila Zanskar Valley samples (reported by Sana Ullah) and not smelted copper. The metal ‘is so soft that depressions are formed when pressed by finger nails’. The Hellenistic influence in this wonderful work of art is quite apparent.

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Another famous Buddha image in copper was found in Sultanganj on the Ganges, about midway between Bhagalpur and Monghyr in Bihar. Without its base the figure stands 2 metres or 78.74 inches high, and weighs nearly a ton. (Mitra, 1864) Vincent Smith pointed out that this copper statue has been wrongly described as ‘bronze’ in the Handbook of the Museum and Art Gallery of Birmingham where it is at present located.

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Mitra (1864: 360) described:

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The material is a very pure copper, cast in two layers, the inner one in segments on an earthen mould and held together by iron bands which were originally 3/4 of an inch thick, now worn down by rust. The casting of the face down to the breast was effected in one piece, the lower parts down to the knee in another and then the legs, feet, hands and back in several pieces.

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The outer layer of copper seems to have been cast over the inner one presumably by the cire perdue process. A hole bored through the breast revealed that the substance of the mould inside was like a friable cinder originally consisting of a mixture of sand, clay, charcoal and paddy husks. The virtual transparency of the outer copper garments reflects the greatest credit on the copper-smiths who made this statue. Lumps of copper ore were found in the vicinity suggesting that the smelting and casting operations were done on the spot.

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In the light of the discovery of a coin of the last Western Satrap of Saurāṣṭra accompanied with one of Chandragupta II in the vicinity of the nearby monastery, Vincent Smith concluded that the copper statue belonged to the fifth century AD. (Neogi, 1917, 1979: 23) We have earlier mentioned the fasting Śākyamuni statue of Gujarat made of pure copper. The two masterpieces of pure copper suggest some technological link and might belong to the same era.

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It is significant that pure unalloyed copper was used to make the statues instead of alloyed copper such as bronze or brass; this might have some religious significance. Loṭās used for religious ceremonies were also made of unalloyed copper. The famous iron pillar at Delhi, also made in this Gupta era, constitutes of unalloyed wrought iron.

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The celebrated Chinese traveller, Hiuen-Tsang saw and reported a gigantic copper colossus of Buddha image, no less than 80 ft in height, standing upright towards the east of the great Nalanda convent. This was the work of the seventh century AD, during the reign of Raja Purnavarman. The marauding invaders of the twelfth century did not appreciate the sanctity of these statues; the representatives of another group of invaders discovered in 1862 ‘the right foot of the Sultanganj statue ten feet under the surface and about a mile away from the monastery, and eventually placed this statue in the Birmingham Museum for the posterity to appreciate at least the technical excellence of the ancient Indian copper-smiths.

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In conclusion, we should refer to the huge number of artefacts and works of art made (in ancient India) of alloyed copper with variable proportions of arsenic, tin, lead and zinc. We may review this topic in more detail after discussing the advent of zinc metallurgy in ancient India.

References

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Agrawal, D.P., 1971, *The Copper-Bronze Age in India*, Munshiram Manoharlal, New Delhi. Agrawal, D.P., Krishnamurthy R.V. and Kusumgar, Sheela, 1978. “Arsenical Coppers in the Indian Bronze Age”, In *MADHU: Recent Researches in Indian Archaeology and Art History — Sri M.N. Deshpande Festschrift*, Agam Kala Prakashan, Delhi, pp. 9-16. Agrawal, D.P., 1982, “The Indian Bronze Age Cultures and their Metal Technology”, In *Advances in World Archaeology*, Volume 1, Academic Press, 1982, pp. 213-64.

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—, 1984, “Metal Technology of the Harappans”, In *Frontiers of the Indus Civilization*, edited by B.B. Lal and S.P. Gupta, Books and Books, Delhi, pp. 164-71.

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Asthana, Shashi, 1985, *Pre-Harappan Cultures of India and the Borderlands*, Books and Books, New delhi.

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Bhardwaj, H.C., 1970, “Problem of Advent of Copper in India”, In *Indian Journal of History of Science*, 5, Nov. 1970, pp. 229-37.

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—, 1979, *Aspects of Ancient Indian Technology*, Motilal Banarsidass, Delhi.

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Biswas, A.K. et al., 1990, “Archaeo-material Studies in India”, In *Historical Archaeology of India*, edited by A. Ray and S. Mukherjee, Books and Books, New Delhi, pp. 49-66.

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Caldwell, J.R., 1967, *Investigations at Tal-i-Iblis* (edited), Illinois State Museum Preliminary Reports, no. 9, Springfield.

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Chakrabarti, D.K., 1986, “Mining in Ancient and Medieval India”, In *The Cultural Heritage of India*, Volume 6, Ramakrishna Mission Institute of Culture, 1986, pp. 188-96.

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Dunn, J.A., 1965, *Bulletin of the Geological Survey of India*, 23, (Copper), pp. 75-90.

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Friedman. A.M. et al., 1966, *Science*, Vol. 152, p. 1504.

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Ghosh, A. (ed.) 1989, *An Encyclopaedia of Indian Archaeology*, 2 Volumes, Munshiram Manoharlal Publishers, New Delhi.

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Hegde, K.T.M., 1969, *In Excavations at Ahar*, Deccan College, Poona, pp. 225-28.

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Hegde, K.T.M., and Pandey, S.N., 1970-72, “Chemical Analysis of Some Copper Objects from Mitathal”, In *Studies in Museology*, Vols. 6-8, 1970-72, edited by S.M. Nair, University of Baroda.

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Hegde, K.T.M., and Ericson, J.E., 1985, “Ancient Indian Copper Smelting Furnaces”, In *Furnaces and Smelting Technology in Antiquity*, edited by P.T. Craddock. Occasional Paper No. 48, British Museum, London, 1985, pp. 59-67.

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Hegde, K.T.M., 1989, Private Communication.

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Kerr-Cross, D., 1950, “Ancient Mines and Minerals in India”, In *Indian Minerals*, 4, 1, 1950, pp. 5-10.

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Maddin, R., Wheeler, T. Stech, and Muhly, J.D., 1980, “Distinguishing Artifacts Made of Native Copper”, In *Journal of Archaeological Science*, 7, pp. 211-25, vide also *Journal of Metals*, 31, 9, Sept. 1979, pp. 16-18.

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Margabandhu, G., 1974. “A Note on Some Ancient Indian Mirrors”, In *Puratattva*, 1974, No.7, pp. 94-95.

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Mitra, R.L., 1864, *Journal of Asiatic Society of Bengal*, p. 360.

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Neogi, P., 1917, *Copper in Ancient India*, reprint of 1979, Janaki Prakashan, Patna.

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Rao, S.R., 1973, *Lothal and the Indus Civilization*, Asia Publishing House, Bombay.

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—, 1979 and 1985, *Lothal*, Archaeological Survey of India.

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—, 1987, “Mining and Metallurgy of Copper in Ancient India”, In *Archaeology and History — Essays in Memory of Shri A. Ghosh*, Volume 1, edited by B.M. Pande and B.D. Chattopadhyaya, Agam Kala Prakashan, Delhi, 1987, pp. 383-98.

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Swarna Kamal, 1980, *Studies in Metallic Art and Technology of Gujarat*, Museum and Picture Gallery, Baroda.

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Thomson, F.C., 1958, *Man 58 (i)*, p. 1.

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