The richness and variety of India`s metallurgical history has by and large remained outside the general historical perception of the land or been confined essentially to generalizations about the impact of the introduction of iron on agriculture. However the abundance of her mineral resources, the richness of her pre-industrial metallurgical tradition, the antiquity and abundance of her ancient metal objects and the still unexplored dimension of her ancient mines should mark out India as a great metallurgical centre of antiquity.
Basically, it is a matter of focusing on ancient mining and metallurgy as specific research problems not merely in archaeology but also in geology, metal sciences, ethnography and history. Geological research on the distribution of various metals has no doubt been a serious concern of various relevant national bodies, but the resources which, despite their modern commercial unsuitability, would have been adequate for pre-industrial smelting and the locations and characters of innumerable pre-modern mining shafts have escaped systematic attention in the field. In view of the vast mass of ethnographic data available in the British Indian documents on the production of both metals and metallic artifacts and the continuity of various metal-based craft traditions in various parts of the subcontinent, the ethnographic understanding of the ancient data is also very significant in the Indian context. Historically, the production and the economic organization of metals and metal crafts in some metal-rich areas of the subcontinent before the coming of the British are the sources of the traditional way of organizing metal industry. On their part, archaeologists have been unmindful of the rich possibilities of investigation from all these points of view.
As per the historical evidences, the copper metallurgy was effectively established at Mehrgarh in Period III c. late fifth or early fourth millennium BC. By the close of the fourth millennium BC, the knowledge of cop-per and copper-related metallurgy, gold and silver became widespread. There is a possibility of deliberate lead and arsenic alloying to the extent of 1 per cent in two analysed specimens from Ganeshwar in the Aravallis. It appears that by this time the major copper sources of the area in Baluchistan, Rajasthan
were known and used. The establishment of the Aravallis as one of the oldest and long-standing areas of ancient Indian metallurgy and the realization that it played a major role in the origin of the Indus civilization by being a major element in the intensification of craft activities before its beginning must be considered a major step forward in the archaeology of this period.
Given their background and the complex economic life of the civiliza-tion, it is no wonder that the craftsmen of the mature Harappan civilization were adept in making not merely a wide range of artifacts but also in using an extensive series of alloys namely tin, arsenic, lead, nickel, tin and arsenic, tin and lead, arsenic and lead, tin and nickel, lead and nickel, and finally, zinc. Tin was the most widely used alloy, but it is the pure copper tradition which dominated. This fits in with the continuing tradition of ritual purity of pure copper vessels among Indian craftsmen. As far as the typology of Harappan copper objects is concerned, types like spiral-headed pins, which were once championed as west Asiatic imports, are now being found to have been very much a part of the sub-continental complex from Manda in Jammu to Ganeshwar in Rajasthan and Inamgaon (early Jorwe level) and Daimabad (late Harappan level) in Maharashtra
. It is also clear that some of the basic techniques and style of modern Indian craft tradition in copper and its alloys (including the dhokra tradition) and gold and silver jewellery go back to the Indus civilization context.
Another major metallurgical development in India has been the realization that the Rajasthan-Haryana zone of copper metallurgy supplied finished tools and other products to Malwa and Maharashtra in the neolithic-chalcolithic context. The Aravalli zone signature is clear on the copper celts from Kayatha. Moreover, it has been believed that the specimens of the late Harappan `Daimabad hoard` went there from the same region. In the case of the upper Gangetic valley `copper hoards`, now identifiable with the ochre coloured pottery tradition of late Harappan affinity, the linkage is clearly towards the Rajasthan-Haryana zone of metallurgy. It is more significant that the spread of this tradition outside their core area, over a wide geographical area involving Gujarat, the Deccan and southernmost reaches of Tamil Nadu.
In addition to that, the picture of metallurgy in east India is not particularly varied or early; by the first half of the second millennium BC copper metallurgy seems to be secure, although that is no reason to place the Chhotanagpur plateau and West Bengal
`copper hoard` finds so early. They dated certainly from the historic periods. More interesting is the opening up of the tin source of the Chhotanagpur plateau in the second millennium (Sonpur in Bihar, Bahiri in West Bengal) B.C. Copper-smelting occurs in the chalcolithic context at Golbai in Orissa and should date from the second millennium BC. High arsenic alloying from the early first millennium BC context at Sankarjang in Orissa
is interesting and suggests a separate strain of copper metallurgy. The source of tin in a copper object of the Neolithic level of Brahmagiri in Karnataka
is interesting too. It has been found that there is a possibility that the rich deposit of tin in Bastar came to be exploited by this time.
High tin alloying, which has survived in Kerala, was certainly a part of the Indus civilization tradition and this tradition is more marked and widespread in early historic India from Taxila to the Asura graves of eastern India and the Nilgiri graves of Tamil Nadu. Occasionally, the tradition may also be observed among later images and coins. A distinct feature of the early his-toric context is the production of brass.
A major development in the study of ancient Indian metallurgy since the mid-1970s has been the mounting evidence of the early antiquity of iron technology in different parts of the subcontinent namely in Kashmir, Rajasthan etc. Moreover, iron is found as a part of the continuing chalcolithic black-and-red ware sequence in eastern India, as a part of the continuing chalcolithic pottery sequence in Malwa, with early megalithic graves at Hallur and Kumaranahalli, with the pre-painted grey ware, black-and-red-ware level at Jakhera, in the black-and-red ware context at Raja Nal-ka-Tila in Sonbhadra district, Uttar Pradesh
, and finally, an `iron object` in the Harappan context. The combined evidence is unequivocal enough to suggest that right from the early part of the second millennium BC there was a steady growth in the familiarity with iron in different parts of the subcontinent and that towards the closing centuries of the second millennium BC it was inducted into the economy of the Ganga plain. The fact that early historic urban growth in this region was not pos-sible till several centuries later is sure enough indication of the fact that the impact of iron on the economy was slow.