Metallurgy in Pre-Columbian America
Encyclopedia
Metallury in pre-Columbian America is the extraction and purification of metals, as well as creating metal alloys and fabrication with metal by Indigenous peoples of the Americas
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...

 prior to European contact in the late 15th centuries. Indigenous Americans have been using native metals from ancient times, with recent finds of gold artifacts in the Andea
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

n region dated to 2155—1936 BCE. and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n copper finds dated to approximately 5000 BCE. The metal would have been found in nature without need for smelting
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...

 techniques and shaped into the desired form using heat and cold hammering techniques without chemically altering the metal by alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

ing it. To date "no one has found evidence that points to the use of melting, smelting and casting in prehistoric eastern North America." In South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 the case is quite different. Indigenous South Americans had full 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...

 with smelting and various metals being purposefully alloyed. Metallurgy in Mesoamerica
Metallurgy in pre-Columbian Mesoamerica
The emergence of metallurgy in pre-Columbian Mesoamerica occurred relatively late in the region's history, with distinctive works of metal apparent in West Mexico by roughly AD 800, and perhaps as early as AD 600...

 developed from contacts with South America.

South America

South American metal working seems to have developed in the Andean region of modern Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

 and Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

 with gold being hammered and shaped into intricate objects, particularly ornaments. Recent finds date the earliest metal work to 2155 to 1936 BCE. It was found in the context of a society undergoing social and economic changes but still very much small food producer and not quite sedentary yet. This breaks away from the idea that this type of metal work developed in societies with enough food surplus to support an elite. Rather than being a product of a hierarchical society gold might have been meshed in the creation of it. Further evidence for this type of metal work comes from the sites at Waywaka, Chavin and Kotosh , and it seems to have been spread throughout Andean societies by the Early horizon
Cultural periods of Peru
This is a chart of cultural periods of Peru and the Andean Region developed by Edward Lanning and used by some archaeologists studying the area...

 (1000—200 BCE)

Unlike in other metallurgy traditions where metals gain importance due to their widespread use from weaponry to everyday utensils, metals in South America (and later in Central America) were mainly valued as adornments and objects representative of a high status (this not to say that some more functional objects were not being produced). It is during the Early horizon that advancements in metal working result in spectacular and characteristically Andean gold objects made by the joining of smaller metal sheets and also gold-silver alloy appears.

Two traditions seem to have developed along side each other- one in northern Peru and Ecuador, and another in the Altiplano
Altiplano
The Altiplano , in west-central South America, where the Andes are at their widest, is the most extensive area of high plateau on Earth outside of Tibet...

 region of southern Peru, Bolivia and Chile. There is evidence for smelting
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...

 of copper sulphide in the Altiplano region around the Early horizon. Evidence for this comes from copper slag recovered at several sites, with the ore itself possibly coming from the south Chilean-Bolivian border.

Evidence for fully developed smelting however only appears with the Moche
Moche
'The Moche civilization flourished in northern Peru from about 100 AD to 800 AD, during the Regional Development Epoch. While this issue is the subject of some debate, many scholars contend that the Moche were not politically organized as a monolithic empire or state...

 culture (northern coast, 200 BCE—600 CE). The ores were being extracted at shallow deposits in the Andean foothill, whether by specialised workers or slaves/prisoners is unclear. In any case the ores are believed to have been smelted at nearby locations, evidenced in the actual metal artefacts and from ceramic vessels depicting the process, which is believed to have been occurring in adobe brick furnaces with at least 3 blow pipes to provide the air flow needed to reach the high temperatures. The resulting ingots would then have been moved to coastal centres where shaping of the object would occur in specialised workshops. Both of the workshops found and studied were located near administrative sections of the respective towns - again indicative of the high value placed upon metal.

The objects themselves were still mainly adornments, now often being attached to beads. Some functional objects were fashioned but they were elaborately decorated and often found within high status burial contexts. For this reason, it is believed that they were still being used more for symbolic purposes. The appearance of gold or silver seems to have been important with a high number of gilded or silvered objects as well as the appearance of Tumbaga
Tumbaga
Tumbaga was the name given by Spaniards to a non-specific alloy of gold and copper which they found in widespread use in pre-Columbian Mesoamerica and South America.-Composition and properties:...

, a copper/gold and sometimes also silver alloy. Arsenic bronze
Copper alloys
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead...

 was also being smelted from sulphidic ores, a practice either independently developed or learned from the southern tradition.

This technology gradually spread north into Colombia, Panama and Costa Rica, reaching Guatemala and Belize by 800 CE.

It is really only with the Incas that metals gain a more utilitarian use. Nonetheless, it remained a material through which to display wealth and status. The characteristic importance placed on colour, which had led to some of the earlier developments, was still present (Sun/Moon association with gold/silver). Metal other than gold also had an intrinsic value with the axe pieces being of particular note in this regard. With the spread of metal tools being championed by the Incas it is thought possible that a more Old World use of metals would have become more common. In any case "Bronze can be seen as an expensive substitute for the equally efficient stone."

Mesoamerica

Metallurgy only appears in Mesoamerica
Mesoamerica
Mesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...

 in 800 CE with the best evidence from west Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. Much like in South American, fine metals were seen as a material for the elite. Metal's special qualities of colour and resonance seemed to have appealed most and then led to the particular technological developments seen in the region.

Exchange of ideas and goods with peoples from today’s region of Ecuador and Colombia (likely via a maritime route) seems to have fueled early interest and development. Similar metal artefact types are found in West Mexico and the two regions: copper rings, needles and tweezers being fabricated in the same ways as in Ecuador and also found in similar archaeological contexts. There is also a multitude of bells found, but in this case they were cast using the same lost-wax casting method as seen in Colombia. During this period, copper was being used almost exclusively.

Continual contact kept the flow of ideas from that same region and latter, coinciding with the development of Andean long distance maritime trade, influence from further south seems to have reached the region and lead to a second period (1200-1300 CE to the Spanish arrival). By this time, copper alloys
Copper alloys
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead...

 were being explored by West Mexican metallurgists some because the different mechanical properties were needed to fashion specific artefacts like particularly axe monies - further evidence for contact with the Andean region - but in general developed the new properties such alloys introduced to match their own regional representations - specially wirework bells, which at times had such high tin content in the bronze that it was irrelevant for its mechanical properties, but gave it a golden colour.

The actual artifacts and then techniques were imported from the south, but west Mexican metallurgists worked ores from the abundant local deposits- the metal was not being imported. Even when the technology spread from West into north-eastern, central and southern Mexico, artifacts that can be traced back to West Mexican ores are abundant, if not exclusive. It is not always clear if the metal reached its final destination as an ingot, an ore or a finished artifact. Provenance studies on metal artifacts from southern mesoamerica cast with the lost-wax technique and dissimilar to west Mexican artefacts have shown that there might have been a second point of emergence of metallurgy into mesoamerica there since no known source could be identified.

The Aztecs did not initially adopt metal working, even if they had acquired metal objects from other people. However, as conquest gained them metal working regions, the technology started to spread. By the time of the Spanish conquest, a blooming bronze smelting technology seemed to be nascent.

North America

Archaeological evidence has not revealed metal smelting or alloying of metals by pre-Columbian
Pre-Columbian
The pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during...

 indigenous peoples north of the Rio Grande River; however, they did use native copper
Native copper
Copper, as native copper, is one of the few metallic elements to occur in uncombined form as a natural mineral, although most commonly occurs in oxidized states and mixed with other elements...

 extensively.

As widely accepted as this statement might be it should not be considered synonymous with a lack of metal objects, as it points out native copper was abundant particular in the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

 region and "overlooks the simple fact that there was really very little to be gained by smelting..." The latest glacial period had resulted in the scouring of copper bearing rocks. Once the ice retreated, these were readily available for use in a variety of sizes. Copper was shaped via cold hammering into objects from very early dates (Archaic period in the Great Lakes region: 8000-1000 BCE). There is also evidence of actual mining of copper veins(Old Copper Complex
Old Copper Complex
Old Copper Complex is a term used for ancient Native North American societies known to have been heavily involved in the utilization of copper for weaponry and tools. It is to be distinguished from the Copper Age , when copper use becomes systematic.The Old Copper Complex of the Western Great Lakes...

), but disagreement exists as to the dates.

Unlike their Southern counterparts, North American metallurgy had a more utilitarian purpose from very early on, with losing sight of the prestige attached to the metal artifacts (knives, fishhooks, bracelets).

Extraction would have been extremely difficult. Hammerstone
Hammerstone
In archaeology, a hammerstone is a hard cobble used to strike off lithic flakes from a lump of tool stone during the process of lithic reduction. The hammerstone is a rather universal stone tool which appeared early in most regions of the world including Europe, India and North America...

s may have been used to break off pieces small enough to be worked. This labor intensive process might have been eased by building a fire on top of the deposit, then quickly dousing the hot rock with water, creating small cracks. This process could be repeated to create more small cracks.

The copper could then be cold-hammered into shape, which would make it brittle, or hammered and heated in an annealing process to avoid this. The final object would then have to be ground and sharpened using local sandstone. Numerous bars have also been found, possibly indicative of trade for which their shaping into a bar would also serve as proof of quality.

Great Lake artifacts found in the Eastern Woodlands of North America seem to indicate there were widespread trading networks by 1000 BCE. Progressively the usage of copper for tools decreases with more jewellery and adornments being found. This is believed to be indicative of social changes to a more hierarchical society.

However this Great Lake model as a unique source of copper and of copper technologies remaining somewhat static for over 6000 years has recently come into some level of criticism, particularly since other deposits seem to have been available to ancient North Americans, even if a lot smaller.
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