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Minerals and Metals in Ancient India v1.c11.s6: Sources of Minerals at Mohenjo-Daro

Minerals and Metals in Ancient India v1.c11.s6

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English

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Sources of Minerals at Mohenjo-Daro

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One of the burning questions faced by the excavator of Mohenjo-Daro was related to the sources of all minerals, found there. Edwin Pascoe, former director of the Geological Survey of India, tried to resolve the question.

Gold

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Apart from iron, the most widely distributed and most useful metal in India is gold. The sands of the majority of its rivers have yielded gold though usually in very small quantities when washed. In fact, gold washing has been practised in the past in every province of India. The stream of the Dharwar district of Bombay have for instance yielded gold, and traces of old workings are to be seen in the Sangli state and near Hosur. In Hyderabad (Deccan) ancient workings have been noticed at Hutti, Topuldodi and Wondalli. All these areas have since been mined on a large scale. In Madras, old workings have been found in Anantapur, Coimbatore, Hadabanatta, Kavudahalli, Wynaad and near Porsegaundanpalay. The old workings in S.E. Wynaad were made by a mining community known a Karumbars. Eastwick has endeavoured to show that the great sources of gold, reported to have been seized by the former invaders of India, came from the Wynaad mines. He in fact identifies India as the land of Ophir. In Mysore, old workings are widely distributed and gold has been found in every district except that of Bangalore, where Kolar provides now over 90 per cent of India's production.

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In Afghanistan, gold occurs 3 miles north of Kandahar. It is obtained in small quantities also from the north side of the Hindukush. Other reported sources are the streams during the Kuh-i-Baba, streams in Kohistan and above Laghman and Kunar. Apart from that there were other countries from where gold was obtained, i.e., Persia, Tibet, China, Arabia etc.

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∗ Views of Pascoe quoted by Marshall and MS-II, pp. 674-85.

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Now the point is that although there are many possible sources for the gold of Mohenjo-Daro, the chances seem more in favour of Southern India. The gold of India is said to have been worked upon for at least twenty-five centuries, although Afghanistan, Western Tibet and parts of Persia are nearer. So southern India would seem to have been the most accessible area. (MS-II, 674-75)

Silver

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In the Bhagalpur, Manbhum, Monghyr and Singhbhum districts of Bihar and Orissa, silver has been found associated with lead, but neither metal in considerable quantity. Similar occurrences have been met within the Central India, Drug, Hoshangabad and Jabalpur district. Silver associated with gold is produced in considerable quantity today in Kolar in Mysore, and to a much smaller extent at Anantapur in Madras. An ancient lead mine, the lead from which yields a small quantity of silver exists in Farinjal in the Ghorband Valley of Afghanistan. Silver may also have been derived from the many other lead localities of southern Afghanistan. In the same country, well-known silver mines existed near the head of the Panjshir valley in the Hindu Kush; silver deposits were also formerly worked upon near Heart. Persia is said to be very rich in silver-bearing lead ore. Thus it may be said that if the ancients knew how to separate silver from gold, it is possible that the Mohenjo-Daro supplies might have come with the gold from southern India. The art of separating silver from lead has been known for many generations, so that the Farinjal mine of Afghanistan, the Gumush Khanch mines of Armenia and the many lead mines of Persia might be looked upon as possible sources. (MS-II, 675)

Copper

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The best known deposits of copper in India are those of Singhbhum in Bihar and Orissa. Remains of old excavations and mounds of copper slag from a worked out ore have been noted in Indore. Old copper workings are common in Madras, Coimbatore, Guntur and especially Nellore. Many places in the Punjab and Rajputana yield copper, the most important being Khetri and Singhana, both in the Jaipur area. In Afghanistan ancient copper workings have been found near the Safed-Kuh between Kabul and Kurram. Rich veins of copper ore are also said to exist in the Shah Maqsud and the Sirdars of Kandahar. Copper ore is abundant in Persia. Amongst all the above sources, the copper localities nearest to Mohenjo-Daro are: the Jaipur state of Rajputana, the Shah Maqsud and the other areas in Southern Afghanistan and Robat in the extreme west of Baluchistan. (MS-II, 676)

Lead

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Considerable quantities of lead ore were formerly extracted from mines near Ajmer in Rajputana. Lead is known to occur at several places in Bihar and Orissa, the central provinces and the Cuddapah and Kurnool district of Madras. With the exception of iron, there is perhaps no metal whose ores appear to have been worked to so large an extent in India as those of lead. An ancient lead mine with very extensive workings has already been referred to as occurring at Farinjal in the Ghorband valley of Afghanistan. Lead ore is common in many localities in southern Afghanistan. The Mohenjo-Daro lead may well have come from Ajmer. The old mines in this District were of great extent and (in 1830) had the appearance of having been worked for centuries. The metal may otherwise have come from the Farinjal mine in Afghanistan, or other mines in the south of that country or from Persia.

Lapis Lazuli

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The name is derived from the Persian word lajward meaning ‘blue colour’. It is recorded from the neighbouring countries of Tartary, Tibet and China but the best known and most important locality is the valley of the Kokcha, south of Firgamu in Badakshan, the most northernly province of Afghanistan. It is also reported to occur in China, Persia, Tibet and Bokhara. Pascoe concluded that most probably the lapis lazuli of Mohenjo-Daro came from the Badakshan Province of Afghanistan. (MS-II, 677)

Turquoise

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It derives its name from the country of Turkey. However the supply originated from Persia, and merely passed through Turkey towards Europe. Turquoise takes on a greenish tinge on exposure to sunlight and for this reason most ancient ornaments of this mineral are definitely greenish in tint. The finest turquoise is found in Persia, where the mines are known to have been worked for at least eight centuries. The principal locality is near Nishapur in the Khorasan provinces, other localities being near Kirman and Karik and near Mashiz. It is also said to occur in Turkestan. As there is no reference of its finding from India, so it is not plausible to accept that turquoise came from Ajmer hills of Rajputana. It seems most probably that the ultimate source of the Mohenjo-Daro turquoise was the Persian province of Khorasan. (MS-II, 678)

Amazon Stone

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Formerly Amazon stone or Amazonite, a green variety of microcline feldspar was obtained only from the Urals. But this microcline is common in India. This precious variety has so far been reported only from Dodabetta in the Nilgiri hills and possibly from the Padar district of Kashmir. The Mohenjo-Daro material may well have come either from these localities.

Rock Crystal

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Rock crystal is a very common form of semi-precious silica or quartz and is fairly widespread in its occurrence. It has been worked upon at many localities in India. The lapidaries of Cambay obtain their supplies from Tankara in the Kathiawar peninsula. Large prisms were formerly obtained in the bed of the Godavari near Rajahmundri and in the stream beds of Tanjore both in Madras. Delhi was formerly another source. Interesting little bi-pyramidal crystals have for a long time been obtained from the red marls of Mari in the Mianwali district of the Punjab; these are known as ‘Mari diamonds’. The Alps and India are supposed to have furnished the ancients with their supplies of rock crystal, and it is not unlikely that the Mohenjo-Daro inhabitants obtained theirs either from Mari, from the Kathiawar peninsula or from Vellum in the Tanjore district of Madras.

Steatite

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Steatite or soap-stone is a massive form of talc, a mineral which is said to have derived its name from the Arabic talq. The Egyptians used it usually coated with blue glaze. Its most conspicuous properties are resistance of heat and great softness. The mineral is widely distributed among the crystalline rocks of India. The nearest place of occurrence to Sind are Rajputana, Gisgarh, Morra, Mysore, Jabalpur, Bihar and Orissa. The present-day production comes mostly from Jabalpur and Salem. The most likely source of the Mohenjo-Daro material seems to be Rajputana. (MS-II, 678)

Alabaster

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True alabaster is a hydrated sulphate of lime but the name was applied in ancient times generally to the carbonate. True alabaster is sufficiently soft to take a scratch from the finger-nail and does not effervesce with hydrochloric acid. Oriental alabaster, the carbonate of lime was used in Ancient Egypt for canopic jars and other objects. Its name may have its origin in the alabastar-ointment vases or perfume bottles which are formerly made out of this stone. It is found as travertine deposited from calcareous springs or as a stalagmite on the floor and walls of limestone caverns. A very beautiful aragonite travertine occurs in considerable quantity 1-1/2 miles west of Topehi on the road to Bamian in Afghanistan. This alabaster is merely a refined and semi-transparent form of gypsum. It occurs largely in all the younger tertiary deposits of Afghanistan. The bed at Dasht-i-safed in Kamard is of the semi-translucent variety known as alabaster and would make a very handsome ornamental stone.

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Gypsum is plentiful in the neighbourhood of Mohenjo-Daro itself and some suitable fine grained bed as probably available at no great distance from the city. Thick beds of it of sufficient purity are found in the Kirthar range of Sind. Kutch contains large quantities of the mineral, and a certain amount is obtainable in Kathiawar and Rewa Kantha. Gypsum in enormous quantities including massive beds of considerable purity and variety of colour extend along the base of the salt range in the Punjab. The gypsum of Rajputana is mostly impure. All of these local sources may have supplied Mohenjo-Daro with true alabaster. (MS-II, 679)

Haematite

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Crystalline haematite which is used for ornamental purpose is extremly hard, fine grained compact material or large crystals. Enormous quantities of haematite occur in Bihar and Orissa etc. and much of this is hard, fine-grained compact ore with a good metallic lustre. Specimens may well have been picked up in the stream beds by the ancient people and used for ornamental purpose. The occurrence of haematite in the islands of the Persian gulf such as Hormuz and on the opposite coast of Persia is perhaps worth special mention in view of the fact that the mineral is usually conspicuous. The Mohenjo-Daro supplies may well have come from this source. (MS-II, 680)

Amethyst

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The term ‘Oriental Amethyst’ is sometimes applied to violet coloured corundum. True amethyst or violet coloured quartz is found in a very pure state in the gem gravels of Ceylon. This mineral has been found in the Santal Parganas of Bihar and Orissa and sometimes in the Deccan Trap. The occurrence of amethyst quartz in the vicinity of Hyderabad has been noticed. Amethyst is found at several localities in the Bashahr portion of the valley of the Sutlej. There seems little doubt that the Mohenjo-Daro material was derived from the Deccan trap. (MS-II, 680)

Slate

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Poor slate occurs in the Manbhum and Singhbhum Districts of Bihar and Orissa.

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Good quality is known to occur in Baroda, and there are quarries of this rock in Bijapur. Slate of fair quality occurs in Gwalior. The most likely source for slate nearest to Mohenjo-Daro, seems to be Rajasthan.

Agate, Carnelian, Onyx and Chalcedony

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Agate, carnelian and onyx are of common occurrence in the amygdaloidal flows of the Deccan and Rajmahal traps and the chief sources of supply are the rivers that drain the areas covered by these rocks. The beds of Krishna, Godavari and Bhima rivers have been specially noticed in this connection. The agate employed by the lapidaries of Jabalpur is largely derived from the Narmada Valley, especially from Bhera Ghat or the Marble rocks. Nodules of agate are found in plenty in the Rajmahal hills. The most valuable of the veined agate, worked into ornaments by the lapidaries of Cambay comes from Rampur in Ahmedabad. The Kaira district of Bombay has yielded a much prized variety of agate. The chief source from which the carnelian and agate workers of Cambay derive their material is in the Rajpipla state near the village of Ratanpur. All these places are close to Mohenjo-Daro and are to be considered as potential sources of agate, moss-agate and carnelian; the chances are more in favour of Kathiawar and Rajpipla. Two of the agate beads from Mohenjo-Daro (brown-white) resemble the ‘pagoda stones’ or agate from Burma. Onyx is widely distributed over parts of Nawanagar. (MS-II, 681)

Jasper-Agate, Jasper and Bloodstone

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The rivers draining the Dharwar and Bijawar formations contain pebbles of a great variety. Conglomerates of material abound in the older rocks of the Satpura range in the Central Provinces. The jasper of Mohenjo-Daro may well have come from Rajputana. Bloodstone, i.e., green jasper variegated with red, has been noted as occurring near Tankara in Kathiawar and in the bed of the Mota Mola river between Firozabad and Sindaghi in the District of Agra. It is also found in Rajputana. Agate-jasper is mentioned as occurring with common agate in the Rajpipla Hills, Broach, and the beds of the Krishna, Godavari and the Bhima rivers. The Mohenjo-Daro specimens may have come from Rajpipla or Rajputana. (MS-II, 682)

Plasma

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The bright green and more or less translucent variety of chalcedony, known as plasma, has been noticed in the beds of the Krishna, Godavari and Bhima rivers. It seems just as likely however to have been obtained from Rajputana.

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TIN The best known tin locality in Asia is the Malay peninsula, including the Tenasserim Division of Southern Burma. Here cassiterite occurs in considerable quantities. Cassiterite is also known to occur in the Palanpur state (Bombay presidency) and in Dharwar district (Bombay) and is reported to have been found in Rewa Kantha. In the Hazaribagh district of Bihar and Orissa, tin ore is found in more noticeable quantity. Tin is known to occur in the Kuh Banan and the Kara Dagh in Persia. So it would be difficult to surmise from which of these sources, if any, the tin found in Mohenjo-Daro was obtained. (MS-II, 682)

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BITUMEN It is found near Isa Khel on the right bank of the Indus in India. Although the quantity is small, but the deposit may have been a little greater in the older times. The nearest bitumen deposits to Mohenjo-Daro would be those of Baluchistan. At Khattan in the Marri hills N.E. of Sibi, there is a considerable deposit. Even a large deposit of bitumen occurs at Hit on the Euphrates and was known to the old Babylonians. So it is difficult to say which of these is more likely to have been the source for the Mohenjo-Daro specimens. (MS-II, 682)

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RED OCHRE Red ochre is of wide occurrence in India, especially in Central India and the Central Provinces. In the latter province the deposits of Jauli, Jabalpur district are well-known and still explored. Extensive beds occur in the Kaimur plateau and many places on the Deccan trap are characterized by the mineral. Amongst the deposits nearest to Sind are Lakhpat in Kutch and those of Padvania and elsewhere in the Rewa Kantha agency. The red ochre of Hormuz and other Persian gulf islands is worth mention on account of its brilliant colour, which must have attracted the very early notice in human civilisation. Its association with salt and gypsum made it more conspicuous. Even today it is dug out in large quantities and shipped to India for use as a pigment. Hormuz, Bu Musa and Halul are the principal islands from which this material is obtained, and the Mohenjo-Daro supplies might well have come by sea from any one or all of them. (MS-II, 683)

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BASALT It is one of the commonest rocks in India, and covers a total area exceeding 100,000 sq miles in the Bombay presidency (including Kathiawar and the Kutch), Hyderabad, and central India. The Mohenjo-Daro material might have come from the Kathiawar peninsula, but basalt was even nearer at hand than that, namely in the Western Sind. An important band of this rock, from 40 to 90 ft thick, stretches for about 22 miles from the Ranikot to Jakhwari, and may well have been used by the ancient inhabitants. (MS-II, 683)

Tachylite

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It is a basaltic or ultra-basaltic glass, and accompaines dykes in the Deccan Trap. The specimens found at Mohenjo-Daro may have come from any part of the Deccan Trap area as for instance, the Kathiawar peninsula or central India.

Nepheline-Sodalite Rock

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Amongst the Mohenjo-Daro beads two were of peculiar interest in that they consist of an uncommon rock — nepheline-sodalite rock, which is found at Kishangarh in Rajputana. The source of the material, therefore is almost undoubtedly the neighbourhood of Kishangarh. The present uninteresting dull grey colour of the beads is the result of weathering and the effect of time. Sodalite when fresh, is of a beautiful azure blue colour and the beads when fresh, much have done credit to their neighbours in jade, agate, jasper, turquoise etc. (MS-II, 683)

Jadeite

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Jadeite or the hard form of jadestone, which all the Mohenjo-Daro jade beads consist of, is found typically in the Myitkyina district of North Burma. The same mineral is reported to occur also in Yunan (China). The material from Rewah state in central India is the nephrite variety, but it is accompanied by some jadeite. It is also reported to occur in Tibet. Thus for the source of Mohenjo-Daro material, there is the choice out of three localities: the Pamirs and eastern Turkestan, Tibet or North Burma. The finding of jadeite objects in Mohenjo-Daro indicates the strong probability of communication with central Asia. (MS-II, 683-684)

Löllingite

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Löllingite is essentially a di-arsenide of iron, FeAs₂, but passes into leucopyrite, Fe₃As₄, and frequently tends towards arsenopyrite, FeAsS. Other sulphides of arsenic are orpiment, As₂S₃ and realgar, AsS. Iron pyrite, FeS₂ sometimes contains arsenic in small amounts. It will be best however to restrict the inquiry to known occurrences of any of the sulphides of arsenic.

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The Indian occurrences of löllingite are (a) Sampthar hill, Darjeeling (arsenic pyrites), (b) Dabur and Dhab in the Hazaribagh district, Bihar and Orissa; lumps of leucopyrite are occassionally found in the mica-bearing pegmatites. Recently leucopyrite was found in the Gamaria mica mine and löllingite in the Durria mica mine, of the Kodarma Forest area, Hazaribagh, (c) Barali, Padar District of Bhutna Valley, Kashmir (arsenopyrite), (d) Chitral N.W.F. province. Orpiment in the past was imported in considerable quantities from Chitral, (e) Arsenical pyrite has been mined at Manikaran in the district of Kangra, Punjab, (f) On the Dharma and Juwar or Niti Ghats in the Almora district (‘yellow arsenic’, i.e., orpiment), (g) Mansiari, Uttar Pradesh, Himalaya—small quantities of orpiment are brought down for sale to the Bagesar Fair, (h) Shankalpa Glacier, Uttar Pradesh, Himalaya. Arsenic is brought into Kabul from Herat. In Asia Minor, arsenic pyrites and orpiment and realgar are known to occur in several places. In the northern Persia, orpiment and realgar occur in the region of Caspian sea, in the Khurdistan mountains and on Kaflan-kuh.

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From the above-mentioned discussion, it seems that most of the mentioned localities are likely sources for the Mohenjo-Daro material. No reliable conclusion in fact can be drawn.

Green Earth

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It is known as ‘glauconite’ and was found to consist mostly of fine chlorite and calcite. Green earth of this nature was discovered from the basalt of Bhusawal. The Mohenjo-Daro sample may have come from zeolite-material, filling the vesicles of the trap, or it may represent the more massive form resulting from the alteration of the trap as a whole, which takes place chiefly at the base of a flow. Large masses of this trap occur in Kathiawar and central India, but less extensive tracts occur in Kutch, in the East Baluchistan and in the Kankar range in the extreme north of the same province. Thus, it seems very probable that it was obtained from either north-eastern or eastern Baluchistan.

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Metals in Mohenjo-Daro

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Among all the metals those have been found in Mohenjo-daro, copper was the earliest and most useful metal. Different types of copper objects (copper head celts, daggers, knives, lance-heads, arrowheads, sickle, statuettes, bangles, amulets etc.) were found in abundance over there. Thus the presence of copper at the earliest stratum of Mohenjo-Daro proves the fact that from a very early period its use was known to the Indians. Now if we look at the sources of copper ore, then one thing would be clear that although this copper was unknown in Sind, yet there were many adjacent places from where it could be obtained. Outside India it was found in Afghanistan. The Indian sources were Baluchistan, Jaipur area, Ajmer, Mewar, Khetri and Singhana which had been worked upon from very early times, and this region could be taken as the source of copper, because the presence of small quantities of sulphur and the absence of tin point to the use of sulphide ore, which abounds in these mines. Even the presence of lead in some of the copper objects (1.58 and 3.28 per cent) throws some light on the source of the metal. This copper ore associated with lead was available from Afghanistan, Baluchistan, Rajputana and Hazaribagh.

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The fact that numerous copper implements have been discovered in several sites in Northern India and Central Provinces (axe heads, swords, harpoons etc.), indicates that at a very early period copper was extensively worked in India. One of the most important findings among these places has been at Gungeria in the Balaghat district of the Central Provinces, which included 424 hammered copper implements and 102 silver laminae weighing 828 and 20 lbs. This has been described by John Evans as the most important discovery of instruments of copper yet recorded in the old world. (MS-II, 481-483)

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Once it was believed that the prehistoric Indians were not acquainted with the art of manufacture and properties of bronze, but the discovery of various bronze objects in the sub-continent has made that theory baseless. On the contrary, the bronze objects (utensils, tools, weapons, statuettes, jewellery), have made it obvious that the Indus people were well acquainted with the metallurgy and properties of bronze, but they failed to replace copper effectively for such purposes simply on account of the limited supply of tin. The Indus people knew the nature of the copper metal; they understood that as the copper is a soft metal and unfit for tools (which requires a keen hard edge), there was the need of a harder alloy, which could be made by using tin. The chemical composition of the bronze objects thus leaves no doubt that the tin content of 4.5-13.2 per cent is not accidental, but was added intentionally to produce an alloy suitable for cutting tools or other purposes. Some of the objects are in a completely oxidized state consisting of a substantial core of white stannic oxide enveloped in a layer of red cuprous oxide and thus affording a visible proof of the use of a high-grade bronze. Thus it proves that within this time the Indus people had acquired a very good knowledge of working of bronze, and they were a step ahead of the experimental stage. Even with the development of bronze, Indus people used bronze and copper simultaneously, and the only possible reason was the scarcity of tin. Since they could not make enough bronze, they had to make copper implements and utensils also. Apart from this, as bronze was limited, they confined its use for special material, i.e., tools, razors, jewellery, etc., (MS-II, 481-83)

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At Mohenjo-Daro, bronze objects have been found in the earliest stratum yet reached; and on the basis of the chronology adopted in the excavation, it can be said that bronze was known in the Indus Valley even earlier than 3000 BC. This may be taken to imply the existence of commercial relations with some region where the invention of bronze took place — some region where deposits of copper and tin ores existed in close proximity to one another. (MS-II, 483)

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Now as an ingredient of bronze, the source of tin is difficult to locate. This ore is scarce in India proper and unknown in Baluchistan. The only authentic Indian deposit existed in the Hazaribagh district, but its possibility may be ruled out. First of all there is the paucity of its deposits and secondly, a regular supply from this area involved a long and perilous voyage and this must have been impossible in those remote ages. So it is probaple that the source of tin and bronze lay towards the north-west which was quite accessible in the then India. Copper was extensively worked in these regions in ancient times, and it is not unlikely that the discovery of the alloy of copper and tin might have taken place in North Persia and its use found way to Indus valley. So it is observed that the daggers and knives discovered in the Indus valley resemble some of the weapons found at Susa, Anau, and in the south-west Caspian area. (MS-II, 483-84)

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Another alloy, composed of copper and arsenic, and comparable with a low grade bronze in hardness, is also encountered in Mohenjo-Daro, although it is not known how it originated and how it came into vogue. Sir Marshall is of the opinion that the addition of arsenic (2-4.5 per cent) was intentional, but it is also possible that some mines of arsenical copper ore were found to yield a very hard and yellowish metal which was much prized for tools, before the introduction of bronze in the Indus Valley. Similar type of alloy objects have been found in early Egypt and Anau. (MS-II, 482)

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It is highly probable that most of the reduction of copper ore was carried out at the mines itself. Lumps of crude copper ingot, plano-convex in shape 6 - 9 inches in diameter and 1 to 1-1/2 inches thick in the centre, have been found, which were according to the excavator evidently produced by the smelting operation in a primitive furnace consisting of a concave depression in the ground. The crude metal was re-melted, for refining, in clay crucibles which were broken up for the recovery of the purified metal. A fragment of such a crucible with the slag sticking to the edges has been found. But no specimen of pure tin or its ore has been found so far at Mohenjo-Daro. (MS-II, 485)

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Typical analysis of the specimens of copper and bronze found at Mohenjo-daro are displayed in the Table 3.1.

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Table 3.1

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Chemical Analyses of Copper and Bronze Found at Mohenjo-Daro

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| S. No. | Specimen | Copper | Tin | Antimony | Arsenic | Iron | Nickel | Lead | Sulphur | Oxygen (by difference) | Remarks |
| 1. | Copper lump | 96.67 | 0.00 | 0.88 | 0.15 | 0.03 | 1.27 | 0.02 | 0.98 | — | Unaltered core |
| 2. | Copper lump | 97.07 | 0.00 | tr. | 0.98 | 0.49 | 0.31 | tr. | 1.15 | — | Unaltered core |
| 3. | Copper lump | 96.42 | 0.00 | — | 0.00 | 0.00 | 0.35 | 0.09 | 0.36 | 2.78 | Partly oxidized |
| 4. | Copper lump | 92.49 | 0.37 | tr. | 1.30 | 1.51 | 1.06 | tr. | 2.26 | 1.01 | Partly oxidized |
| 5. | Fragment of some implement | 95.80 | 0.00 | 0.72 | 0.74 | 0.12 | 0.25 | 1.58 | 0.61 | 0.18 | Unaltered metal |
| 6. | Celt | 94.76 | 0.09 | — | 4.42 | 0.15 | 0.14 | 0.26 | — | — | Unaltered and very hard metal |
| 7. | Copper chisel (?) | 92.41 | 0.00 | 0.10 | 3.42 | 0.59 | 0.15 | 3.28 | 0.05 | — | Unaltered portion |
| 8. | Bronze rod | 91.90 | 4.51 | 1.15 | 1.96 | 0.15 | — | 0.17 | 0.16 | — | Unaltered core |
| 9. | Bronze buttons | 88.05 | 8.22 | 2.60 | tr. | 0.29 | tr. | 0.00 | 0.84 | — | Completely oxidized |
| 10. | Bronze chisel | 86.22 | 12.38 | 0.35 | — | 0.35 | 0.00 | 0.70 | — | — | Completely oxidized |
| 11. | Bronze slab | 82.71 | 13.21 | 0.33 | 1.17 | 0.42 | 0.56 | 0.11 | 0.00 | 1.49 | Partly oxidized |
| 12. | Bronze chisel | 85.37 | 11.09 | tr. | 0.07 | 0.18 | 0.16 | tr. | 0.11 | 3.02 | Partly oxidized |
| 13. | Bronze lump | 83.92 | 12.13 | tr. | 0.00 | 0.00 | 0.17 | 0.17 | 0.00 | 3.61 | Metallic core, partly oxidized |

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Note. — Complete specimen, along with the adhering incrustations, was taken for analysis and the original composition of the alloy has been recalculated from the relative proportions of the metals found therein.

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The analyses indicate the occurrence of four distinct varieties of copper and its alloys at Mohenjo-Daro: (a) crude copper, (b) refined copper, (c) copper-arsenic alloy, (d) copper-tin alloy or bronze.

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From the Table 3.1, specimen Nos. 1, 2 and 4 represent the crude product of the smelting furnace. These are too rich in sulphur to be worked up by hammering and are suitable only for casting heavy or plain objects.

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Specimen Nos. 3 and 5 are good examples of refined copper. No. 3 is well-suited for the raising of vessels of elaborate shapes on account of its remarkable purity and consequent ductility. The presence of over 3 per cent of foreign metals in No. 5 renders it suitable for obtaining sound casting in close moulds. Such small amount of arsenic and antimony will also impart appreciable hardness to copper although not comparable to that produced by tin. There is no doubt that these elements have not been added intentionally but were derived from the original copper ore with which they were associated.

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Specimen Nos. 6 and 7 represent a copper-arsenic alloy which is as hard as a low grade bronze. In these cases it is difficult to decide whether the arsenic was added intentionally in the form of a flux or was derived from an arsenic bearing copper ore. Similar alloy of copper and arsenic was also in use in Egypt, the composition of No. 6 being almost identical with that of a copper strip of the twelfth Egyptian dynasty. It is therefore possible that this kind of alloy was obtained from the same source, both for the Indus Valley and Egypt. Petrie suggests that arsenic was the earliest hardening element for copper in Egypt, and it may be that this alloy was employed for tools in the Indus Valley also, before the advent of bronze.

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Specimen Nos. 9 to 11 represent the various qualities of bronze in use. It is obvious that 11-13 per cent tin alloy was popular and had came into general use during the period under review, although lower grades were also employed to some extent. The preference of the high grade alloy well-suited for sharp-edged tools, with a fairly regular proportion of tin, leaves hardly any doubt that the addition of the white metal was intentional and not the result of mere accident. It is obvious that this stage in metallurgy had been reached after prolonged experimentation and experience with copper and its alloys with arsenic and tin. These specimens are also contaminated with appreciable proportions of antimony and arsenic, which would further augment their hardness. (MS-II, 485)

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The proportion of lead in the bronzes is trifling, which shows that the Indus people had not discovered the valuable property of this metal in rendering the alloy more fusible and more fluid, i.e., more suitable for casting. This partly accounts for the absence of bronze castings of any appreciable size at Mohenjo-Daro. (MS-II, 486)

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LÖLLINGITE

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Another material of considerable imortance at Mohenjo-Daro is löllingite or leucopyrite. It bears evidence of having undergone ignition. Under the action of strong heat, these minerals give off arsenic, or its white oxide when roasted in air. It is therefore likely that this was used in highly arsenious preparations, either for medicinal purposes or for destroying life. It has been shown that the Indus people were metallurgists of considerable experience; so it is obvious that they were well acquainted with the working of arsenical ores of copper which would give off fumes of white oxide of arsenic on roasting. Therefore, it is quite conceivable that they had become acquainted with certain arsenical preparations and their properties and utilized löllingite for the extraction of arsenic.

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The composition of a natural löllingite specimen (B) is given in Table 3.2 with those from the Indus Valley sites. It is obvious that the latter are very poor in arsenic, which is due to the effect of the heat to which these had been subjected. It is difficult to suggest whether löllingite FeAs₂, or leucopyrite, Fe₃As₄ was employed. (MS-II, 690)

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Table 3.2

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Analysis of Löllingite Samples at Mohenjo-Daro

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| | B | I | II | III | IV | V |
| Iron | 27.14 | 54.55 | 49.3 | 45.93 | 51.7 | 48.1 |
| Arsenic | 72.17 | 34.02 | 43.6 | 47.12 | 43.9 | 48.6 |
| Copper | - | 0.92 | 0.7 | - | - | - |
| Sulphur | 0.37 | 1.38 | 0.16 | - | - | - |
| Water | - | 7.68 | 4.7 | - | - | - |
| Insol | - | 1.45 | 0.8 | - | - | 1.9 |
| Sp. gr. | - | 4.0 | 5.6 | - | - | - |

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The use of cerussite (a natural carbonate of lead) and cinnabar (sulphide of mercury), which have also been discovered at Mohenjo-Daro is difficult to understand. It is doubtful if these were employed as pigments, as the analysis of the colours on polychrome pottery do not support this view. Possibly these were used or utilized for cosmetics or medicinal purpose. In this connection it may be mentioned that white lead was employed for plasters, eye salves and hair washes in early times. Cinnabar may also have served as a medicine, but it is more probable that it was employed for the extraction of mercury. This metal was known to the ancient Egyptians and a small vessel full of it was discovered by Schliemann in a grave at Kurna, belonging to the sixteenth or fifteenth century BC. (MS-II, 691)

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Galena was probably used for the preparation of eye salves or paints. (MS-II, 691). Löllingite, cerussite and galena might have been used for metallurgical purposes also.

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