Copper metallurgy in Africa
Encyclopedia
Copper metallurgy in Africa encompasses the study of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 production across the continent
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 and an understanding of how it influenced aspects of African archaeology
African archaeology
The continent of Africa has the longest record of human activity of any part of the world and along with its geographical extent, it contains an enormous archaeological resource...

.

Origins

It was previously believed that sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...

 either did not have a period of using copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 until the nineteenth century, and the available evidence suggested that the region went from the Stone Age
Stone Age
The Stone Age is a broad prehistoric period, lasting about 2.5 million years , during which humans and their predecessor species in the genus Homo, as well as the earlier partly contemporary genera Australopithecus and Paranthropus, widely used exclusively stone as their hard material in the...

 into the Iron Age
Iron Age
The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing...

 or they started smelting iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 and copper at the same time (Herbert 1984). Copper artifacts recovered from Nubia
Nubia
Nubia is a region along the Nile river, which is located in northern Sudan and southern Egypt.There were a number of small Nubian kingdoms throughout the Middle Ages, the last of which collapsed in 1504, when Nubia became divided between Egypt and the Sennar sultanate resulting in the Arabization...

 are the earliest evidence metal smelting sub-Saharan Africa, dating back sometime after 4000 BC and that they were most likely imports from Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

. Present evidence of copper smelting is thought to be introduced to Nubia from Egypt during the early Old Kingdom
Old Kingdom
Old Kingdom is the name given to the period in the 3rd millennium BC when Egypt attained its first continuous peak of civilization in complexity and achievement – the first of three so-called "Kingdom" periods, which mark the high points of civilization in the lower Nile Valley .The term itself was...

 (ca.2686-2181 BC). An Egyptian outpost in Buhen
Buhen
Buhen was an ancient Egyptian settlement situated on the West bank of the Nile below the Second Cataract. It is well known for its fortress, probably constructed during the rule of Senusret III, around the year 1860 BC . The site may have been first established as an outpost in Nubia during the...

 around 2600 BC was established to smelt copper ores from Nubia is the principle evidence for this claim. Also at the temple precinct at Kerma
Kerma
Kerma was the capital city of the Kingdom of Kerma, which was located in present day Egypt and Sudan. The Kerma site has been confirmed by archaeology to be at least 9,500 years old. Around 3000 BC, a cultural tradition began around Kerma...

 a crucible furnace for bronze casting was found dating to 2300-1900 BC, however the source of the tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

 is unknown and that over the next millennium Nubians developed great skill in working copper and other known metals (Childs and Killick 1993).

Discoveries in Agadez
Agadez
-Sources:* Aboubacar Adamou. "Agadez et sa région. Contribution à l'étude du Sahel et du Sahara nigériens", Études nigériennes, n°44, , 358 p.* Julien Brachet. Migrations transsahariennes. Vers un désert cosmopolite et morcelé . Paris: Le Croquant, , 324 p. ISBN : 978-2-91496865-2.*. Saudi Aaramco...

 region of the Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...

 show signs of copper metallurgy
Metallurgy
Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...

 as early as 2000 BC. This date pre-dates the use of iron by a thousand years (Herbert 1984). Copper metallurgy seems to be an independent invention, because there is no clear evidence of influences from Northern Africa. Also the Saharan wet phase was coming to an end, hindering human interactions across it. It appeared not to fully develop yet, fully developed copper metallurgy would have indicated that it would have external origins. The people used native copper at first and experimented with different furnaces styles in order to smelt the ore between 2500-1500 BCE (Ehret 2002). Copper metallurgy has been recorded at Akjoujt
Akjoujt
Akjoujt is a town in western Mauritania. It is located at around . It is the capital of Inchiri region. The town's main industry is gold and copper mining....

 in Western Mauritania. The Akjoujt site is later than Agadez, dating back to around 850 BC. There is evidence on mining in the dating between 850 and 300 BC. Radiocarbon dates from the Grotte aux Chauves-souris mine shows that the extraction and smelting of malachite
Malachite
Malachite is a copper carbonate mineral, with the formula Cu2CO32. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Individual crystals are rare but do occur as slender to acicular prisms...

 goes back to the early fifth century BC. A number of copper artifacts including arrow points, spearheads, chisels, awls and plano-convex axes as well as bracelets, bead and earrings were collected from Neolithic
Neolithic
The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

 sites in the region. Collecting dates from Tropical Africa has been extremely difficult. No dates are available for the copper mine in pre-colonial Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...

 and dates south of the equator dates back to around 345 AD at Naviundu springs near Lubumbashi
Lubumbashi
Lubumbashi is the second largest city in the Democratic Republic of the Congo, second only to the nation's capital Kinshasa, and the hub of the southeastern part of the country. The copper-mining city serves as the capital of the relatively prosperous Katanga Province, lying near the Zambian border...

 in the Democratic Republic of Congo, Kansanshi mine in Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....

 and Kipushi mine in DRC are between the fifth and twelfth century. Sites further south have produced later dates, for example the Thakadu mines in Botswana
Botswana
Botswana, officially the Republic of Botswana , is a landlocked country located in Southern Africa. The citizens are referred to as "Batswana" . Formerly the British protectorate of Bechuanaland, Botswana adopted its new name after becoming independent within the Commonwealth on 30 September 1966...

 dates back between 1480 and 1680, and other major mines Botswana, Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

, and South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 remain undated (Bisson et al. 2000).

Ore Sources

The mineralization of copper is restricted to a few areas in western, central and southern Africa, and some have the richest deposits of copper in the world. In the west, copper has only been found in the arid regions of the Sahel
Sahel
The Sahel is the ecoclimatic and biogeographic zone of transition between the Sahara desert in the North and the Sudanian Savannas in the south.It stretches across the North African continent between the Atlantic Ocean and the Red Sea....

 and southern Sahara
Sahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...

. The main sources of copper are as followed:

1.) Akjoujt in Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...



2.) Nioro-Siracoro in Northern Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...



3.) The Aïr Massif near Azelik and Agadez in Niger

4.) Hufrat-en-Nahas in Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

.

There are not any known mines in tropical West Africa, however copper and lead workings have been in the Benue Rift in southeastern Nigeria. With the exception of a few areas near Kilembe in Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

 and Rwanda
Rwanda
Rwanda or , officially the Republic of Rwanda , is a country in central and eastern Africa with a population of approximately 11.4 million . Rwanda is located a few degrees south of the Equator, and is bordered by Uganda, Tanzania, Burundi and the Democratic Republic of the Congo...

, there are no sources of copper in East Africa. The largest concentration of copper is found Africa is the Lufilian Arc. It is an eight hundred kilometer crescent shaped belt, which extends from the Zambian copper belt to the southern Shaba Province in Congo (Bisson et al. 2000).

Mining and Processing

Early African miners focused on copper oxide
Oxide
An oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....

s and carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

s rather than sulfide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...

s, because oxides and carbonates were easiest to reduce to copper metal than the sulfides. Sulfides were more complex to reduce to metal and required multiple stages, thus they were usually avoided by African miners. Complex deep-mining methods and special tools were not needed, because oxides were structurally weakened by decomposition processes and contained the most desirable ores. The copper mines themselves were most frequently open stope
Stope
Stope may refer to:* Stope, Slovenia, a settlement in central Slovenia* Stope, an underground space produced by Stoping Stopes may also refer to:...

s or open stopes with shafts. Shafts were rare in African copper mining. There are several ethnographic accounts of African copper mining techniques, and they all seem to be on the same technological level. Any variation depended upon different geological circumstances and capabilities of the miners, and although the techniques used seemed to be simple African were very successful in extracting large quantities of high-grade ore (Bisson et al. 2000).

There are more variations of copper smelting than there are of mining, and most of the observations and photos that were taken are in major copper producing areas. There is a lack of evidence of smelting in West Africa; however casting continued to be present and is well documented. The most common ore in Africa is malachite and it was used mainly with hardwood
Hardwood
Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...

 charcoal
Charcoal
Charcoal is the dark grey residue consisting of carbon, and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis, the heating of wood or other substances in the absence of oxygen...

 the smelting process (Bisson et al. 2000).

Central and South Africa

In West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...

 copper was used as medium of exchange, symbols of status and kingship, jewelry, and ritual purposes, and that this a apart of Bantu tradition prior to their expansion into Central Africa
Central Africa
Central Africa is a core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda....

. The use of copper in the Iron Age of Central Africa was produced in because of indigenous or internal demand rather than those from the outside, and it is thought to be a sensitive sign of political and social change (Bisson 1975).Copper appeared to be a prestigious metal in Central and Southern Africa. In Central Africa copper has been found in places where copper is not produced, implying some sort of commerce. Also the majority of artifacts founds suggest that copper primary use in the area was for decorative purposes. The available evidence shows that prior to fifteenth century Zimbabwe
Zimbabwe
Zimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...

an Iron Age site also placed higher value in copper than gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, though the date may have to be pushed with recent carbon dates. It is thought that through trade with India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 and later Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

 that Zimbabwe only started to value gold as prestige metal, however it did not replace copper. Archaeological and documentary sources may skew the record in favor of nonperishable elements of culture and not give enough credit to pastoral and mixed farming activities that were needed to sustain these Iron Age site. They do make it clear that copper was and import part of exchange economy of Central and Southern Africa (Herbert 1984).

East Africa

Copper is almost non-existent for the interior of East Africa
East Africa
East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...

 with a few exceptions particularly Kilwa
Kilwa Kisiwani
Kilwa Kisiwani is a community on an island off the coast of East Africa, in present day Tanzania.- History :A document written around AD 1200 called al-Maqama al Kilwiyya discovered in Oman, gives details of a mission to reconvert Kilwa to Ibadism, as it had recently been effected by the Ghurabiyya...

 and medieval sites in Nubia and Fostat
Fostat
Fustat , was the first capital of Egypt under Arab rule...

, and there is not enough information yet to reconstruct copper on the Swahili Coast
Swahili Coast
The Swahili Coast refers to the coast or coastal area of East Africa inhabited by the Swahili people, mainly Kenya, Tanzania, and north Mozambique...

 (Herbert 1984).

West Africa

In sub-Saharan West Africa there were only two known source of copper that were commercially viable Dkra near Nioro
Nioro
Nioro is the name of two towns in West Africa*Nioro du Sahel: a town in the Kayes Region of western Mali*Nioro du Rip: a town in the southern Kaolack Region, Nioro du Rip Department, of Senegal...

, Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...

 and Takedda
Takedda
Takedda was the name of both a town and a former kingdom in current-day Niger's Western Sahara. The town of Takedda was founded by the Sanhaja, a Berber tribal confederation of the Maghreb. In 1285, a court slave freed by Mari Djata, the founder of the Mali Empire, whom had also served as a...

 in Azelik, Niger. Akjoujt was a significant source of copper, but due to the lack of timber it lost its significance in early historic times. The sources for West Africa’s copper came from southern Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

, northwestern Mauritania, the Byzantine Empire
Byzantine Empire
The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 and Central Europe
Central Europe
Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...

 (Herbert 1973). In West Africa there is a great deal of documentation about copper in trade, but the travelers who wrote these documents only visited the major centers of West African polities and there is no information on the people who lived out the polities or from the savanna and forest zones to the south, in terms of their use of copper. Arab and European trader documented that the principle goods that were in demand in West African markets were salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 and copper. There has been a lack of research done in the savannah
Savannah
Savannah or savanna is a type of grassland.It can also mean:-People:* Savannah King, a Canadian freestyle swimmer* Savannah Outen, a singer who gained popularity on You Tube...

 and forest regions of West Africa so the evidence of the diffusion copper there is spotty at best. Despite West Africa’s rich gold resources, high status people were most often buried with copper grave goods
Grave goods
Grave goods, in archaeology and anthropology, are the items buried along with the body.They are usually personal possessions, supplies to smooth the deceased's journey into the afterlife or offerings to the gods. Grave goods are a type of votive deposit...

. The only sites prior to 1500 AD to have gold were Jenne
Jenne
Jenne can refer to:*Djenné, a city of Mali*Jenne, Lazio, a city and comune in the province of Rome, Italy...

, Tedaoust, and several tumuli
Tumulus
A tumulus is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds, Hügelgrab or kurgans, and can be found throughout much of the world. A tumulus composed largely or entirely of stones is usually referred to as a cairn...

 in Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...

 (Herbert 1984).

Symbolism

It is thought because of copper’s redness, luminosity and sound, it was valued by Africans. For most African cultures the redness could be with life giving powers. It is also noted that the redness is a symbol of transition and it association with transition could explain why the wide use of copper in ritual
Ritual
A ritual is a set of actions, performed mainly for their symbolic value. It may be prescribed by a religion or by the traditions of a community. The term usually excludes actions which are arbitrarily chosen by the performers....

s in various African states. Also its ability to reflect sunlight is suggested represent aggression and liminal boundaries between states, thus emphasizing its transformative properties. Finally, because of copper’s use in bells and drums, it is thought to aid in the summoning spirits, when the instruments are played (Bisson et al. 2000).
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