Metallurgy in pre-Columbian America

South American metal working seems to have developed in the Andean region of modern Peru, Bolivia, Ecuador, Chile, and Argentina with gold and copper being hammered and shaped into intricate objects, particularly ornaments. Recent finds date the earliest gold work to 2155–1936 BC. Ice core studies in Bolivia suggest copper smelting may have begun as early as 700 BC, over 2700 years ago. By 1410–1090 BC, gilding was practiced in coastal Peru. Further evidence for this type of metal work comes from the sites at Waywaka (near Andahuaylas in southern Peru), Chavín and Kotosh, and it seems to have been spread throughout Andean societies by the Early horizon (1000–200 BC). Unlike other metallurgy traditions where metals gained importance through practical use in weaponry and everyday utensils, metals in South America (and later Central America) were mainly valued as adornments and status objects. Though also functional objects were produced, even in the metallurgically advanced Andean cultures of the Inca era stone tools were never completely replaced by bronze items in everyday life. During the Early horizon, advances in metal working produced spectacular and characteristic Andean gold objects made by the joining of smaller metal sheets, and also gold-silver alloy appeared. Two traditions seem to have developed alongside each other – one in northern Peru and Ecuador, and another in the Altiplano region of southern Peru, Bolivia and Chile. There is evidence for smelting 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. Near Puma Punku, Bolivia, and at three additional sites in Peru and Bolivia, portable smelting kilns were used to cast I-shaped "cramps" (fasteners) in place, to join large stone blocks during construction. Their chemical analysis shows The estimated date of these pours lies between 800 and 500 BC. Evidence for fully developed smelting, however, only appears with the Moche culture (northern coast, 200 BC – 600 CE). The ores were extracted from shallow deposits in the Andean foothills. They were probably smelted nearby, as pictorially depicted on the metal artifacts themselves and on ceramic vessels. Smelting was done in adobe brick furnaces with at least three blow pipes to provide the air flow needed to reach the high temperatures. The resulting ingots would then have been moved to coastal centers for shaping in specialised workshops. Two workshops studied were near the administrative sections of their towns, again showing the prestige of metal. Analysis of a Moche statue composed of numerous thin metal layers revealed complex plating and gilding involving a combination of immersion in acidic solutions and the application of extreme heat. The objects themselves were still mainly adornments, now often being attached to beads. In fact, in the Lambayeque and Chimu cultures (750–1400 CE), a wide range of functional metal items were produced such as bowls, plates, drinking vessels, boxes, models, scales and especially beakers (acquillas), but mostly for ceremonial or elite use. Some functional objects were fashioned, but they were elaborately decorated and often found in high-status burials, seemingly still used more for symbolic than for practical 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, an alloy of copper and gold, and sometimes also silver. Arsenic bronze was also smelted from sulphidic ores, a practice either independently developed or learned from the southern tradition. The earliest known powder metallurgy, and earliest working of platinum in the world, was apparently developed by the cultures of Esmeraldas (northwest Ecuador) before the Spanish conquest Beginning with the La Tolita culture (600 BC – 200 CE), Ecuadorian cultures mastered the soldering of platinum grains through alloying with copper, gold and silver, producing platinum-surfaced rings, handles, ornaments and utensils. This technology was eventually noticed and adopted by the Spanish . Coastal communities in the Atacama Desert, as exemplified by those near Tocopilla, produced their own metal objects for practical use in the 900–1400 CE period. in the Museo del Oro, Bogotá Metallurgy gradually spread north into Colombia, Panama and Costa Rica, reaching Guatemala and Belize by 800 CE. By , depletion gilding was developed by the Nahuange culture of Colombia to produce ornamental variations such as rose gold. Muisca goldworking, from modern Colombia, made a wide variety of small ornamental and religious objects from about 600 CE onwards. The gold Muisca raft is probably the best-known single object. This is in the Gold Museum, Bogotá, the largest of the six "gold museums" owned by the Central Bank of Colombia displaying gold from the Muisca and other pre-Columbian cultures in the country. Many copper objects produced in the Tiwanaku polity (c. 600–c. 1000) are alloys that are characterized by having approximately 5% arsenic and 4% nickel. Inca Empire At Machu Picchu and other sites, metal was used for bolas, plumb bobs, chisels, gravers, pry bars, tweezers, needles, plates, fish hooks, spatulas, ladles, knives (tumi), bells, breastplates, lime spoons, mace heads, ear spools, bowls, cloak pins (tupus), axes, and foot plough adzes. Nonetheless, they remained materials 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). Metals other than gold also had an intrinsic value, with axe pieces being of particular note in this regard. With the spread of metal tools by the Incas, it is thought possible that a more Old World use of metals would have become more common. In any case, as Bruhns notes, "[b]ronze can be seen as an expensive substitute for the equally efficient stone". It has been claimed that the Inca Empire expanded into Diaguita lands in what is now north-central Chile because of its mineral wealth, but that view is rejected by some scholars. Furthermore, an additional possibility is that the Incas expanded their territorial power into the relatively well-populated eastern region Eastern Diaguita valleys (present-day Argentina) to obtain labor to send to Chilean mining districts. Farther south in Chile, Mapuche tribes within or near the Incan Empire paid tributes in gold. Among the Mapuche people of central and south-central Chile, gold had an important cultural significance that predates Inca contact. At the time of the Spanish conquest of Chile, Mapuches are reported by various chroniclers to use gold ornaments. Pre-Hispanic Mapuche tools are known to have been relatively simple and made of wood and stone, but a few of them were actually made of copper and bronze. Iron Iron was never smelted by Native Americans, thus the New World never entered a proper "Iron Age" before European contact, and the term is not used with regard to the Americas. But there was limited use of native (unsmelted) iron ore, from magnetite, iron pyrite and ilmenite (iron–titanium), especially in the Andes (Chavin and Moche cultures) and Mesoamerica, after 900 BC and until . Various forms of iron ore were mined, drilled and highly polished. There is considerable evidence that this technology, its raw materials, and end products were widely traded in Mesoamerica throughout the Formative era (2000–200BCE). Lumps of iron pyrite, magnetite, and other materials were mostly shaped into mirrors, pendants, medallions, and headdress ornaments for decorative and ceremonial effect. However, concave iron ore mirrors were apparently used for firing and optical purposes by the Olmec (1500–400BCE) and Chavin (900–300BCE) cultures, and ilmenite "beads" may have served as hammers for fine work. The Olmec and Izapa (300BCE – 100CE) also seem to have used iron magnetism to align and position monuments. They may have developed a zeroth-order compass using a magnetite bar. Some Mesoamerican uses of native iron seem to have been military. Steven Jones proposed that the Olmec sewed ilmenite "beads" into protective mail armour or helmets. ==Central America and Caribbean ==

, Veraguas, Gold, copper and tumbaga objects started being produced in Panama and Costa Rica between 300–500 CE. Open-molded casting with oxidation gilding and cast filigrees were in use. By 700–800 CE, small metal sculptures were common and an extensive range of gold and tumbaga ornaments constituted the usual regalia of persons of high status in Panama and Costa Rica. The earliest specimen of metalwork from the Caribbean is a gold-alloy sheet carbon dated to 70–374 CE. Most Caribbean metallurgy has been dated to between 1200 and 1500 CE and consists of simple, small pieces such as sheets, pendants, beads and bells. These are mostly gold or a gold alloy (with copper or silver) and have been found to be largely cold hammered and sand-polished alluvial nuggets, although a few items seem to have been produced by lost wax casting. It is presumed that at least some of these items were acquired by trade from Colombia. ==Mesoamerica==

bells and tool, Tarascan state (1300 to 1530) Metallurgy only appears in Mesoamerica in 800 CE with the best evidence from West Mexico. Much like in South America, 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 experiences with people from Ecuador and Colombia region seems to have fueled early interest and development. Similar metal artifact 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. A multitude of bells were also found, but in this case they were cast using the same lost-wax casting method as seen in Colombia. In the Tarascan Empire, copper and bronze was used for chisels, punches, awls, tweezers, needles, axes, discs, and breastplates. The Aztecs did not initially adopt metal working, even though they had acquired metal objects from other peoples. However, as conquest gained them metal working regions, the technology started to spread. By the time of the Spanish conquest, a bronze-smelting technology had already been developed. Spanish conquistadors used indigenous smelting technology to produce weapons and tools. ==Northern America==

Archaeological evidence has not revealed metal smelting or alloying of metals by pre-Columbian native peoples north of the Rio Grande; however, they did use native copper extensively. Old Copper Culture Pure native copper was abundant in the Great Lakes region, particularly Michigan, but Wisconsin, Minnesota, and Manitoba as well. The last glacial period had left copper bearing rock exposed and scoured bare. Once the ice retreated, loose pieces were readily available in a variety of sizes for use. 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 native sandstone. Numerous bars have been found with no identified purpose like trade or barter. Great Lake artifacts found in the Eastern Woodlands of North America seem to indicate there were widespread trading networks by 1000 BC. Progressively the usage of copper for tools decreases with more jewelry and adornments being found. This is believed to be indicative of social changes to a more hierarchical society. copper falcon, , OhioThe Old Copper Culture flourished mainly in the Lake Superior region. The Milwaukee Public Museum has an extensive display of objects. At least 50 Old Copper items, including spear points and ceremonial crescents have been discovered in Manitoba. A few more in Saskatchewan, and at least one, a crescent, has turned up in Alberta, 2,000 kilometres from its origin in Ontario. It is most likely that these copper items arrived in the plains as trade goods rather than people of the Old Copper Culture moving into these new places. However from one excavated site in eastern Manitoba it can be seen that some people were moving northwest. At a site near Bissett archaeologists have found copper tools, weapons, and waste material of manufacture, along with a large nugget of raw copper. This site however was dated to around 4,000 years ago, a time of cooler climate when the boreal forest's treeline moved much further south. Though if these migrants moved with their metallurgy up the Winnipeg River at that time they may have continued to Lake Winnipeg, and the Saskatchewan River system., Etowah and Spiro Copper in the Mississippian culture During the Mississippian period (800–1600 CE, varying locally), elites at major political and religious centers throughout the midwestern and southeastern United States used copper ornamentation as a sign of their status by crafting the sacred material into representations connected with the Chiefly Warrior cult of the Southeastern Ceremonial Complex (S.E.C.C.). This ornamentation includes Mississippian copper plates, repousséd plates of beaten copper now found as far afield as Alabama, Florida, Georgia, Illinois, Mississippi, Oklahoma, and Tennessee. Some of the more famous of the plates are of raptorial birds and avian-themed dancing warriors. These plates, such as the Rogan plates from Etowah, the Spiro plates from the Spiro in Oklahoma, and the Wulfing cache from southeast Missouri, were instrumental in the development of the archaeological concept known as the S.E.C.C. Numerous copper fragments were found at the site; metallographic analysis indicated that Mississippian copper workers worked copper into thin sheet through repeated hammering and annealing, a process that could be successful over open-pit wood fires. Iron in the Pacific Northwest lance made from a narwhal tusk with an iron head made from the Cape York meteorite. Native ironwork in the Northwest Coast has been found in places like the Ozette Indian Village Archeological Site, where iron chisels and knives were discovered. These artifacts seem to have been crafted around 1613, based on the dendrochronological analysis of associated pieces of wood in the site, and were made out of drift iron from Asian (specifically Japanese) shipwrecks, which were swept by the Kuroshio Current towards the coast of North America. The tradition of working with Asian drift iron was well-developed in the Northwest before European contact, and was present among several native peoples from the region, including the Chinookan peoples and the Tlingit, who seem to have had their own specific word for the metallic material, which was transcribed by Frederica De Laguna as gayES. although there were also other sources of iron, like that from meteorites, which was occasionally worked using stone anvils. ==See also==