The peoples indigenous to the Americas have often been thought to have been primitives, overwhelmed by Europeans with vastly superior technology. The New World was thought to be an underutilized land populated by natives who had no appreciation for metals, content to use stone, obsidian, and animal products for all of their material needs. This view that indigenous Americans possessed no metallurgy skills persisted all the way into the late sixties . Paradoxically this view of early Americans as ignorant savages is contrasted with the myth of El Dorado, a miraculous metropolis built entirely of gold. Early Spanish explorers brought home tales of riches in gold and silver beyond imagination, and made fortunes melting down the precious metals of the Incas, Mayans, and more. How can these contradictory histories exist; that of the technologically impaired native and of the resource rich cities? Much of this knowledge has been lost to time, from the destruction of native records, from disease and pestilence, and from the salvaging of native artifacts. Thanks to preserved records and modern archeology, we now know that many native cultures possessed highly advanced metalworking techniques, although some of the greatest mysteries of early American metalworking remain yet unanswered.
One of the most important clarifications that needs to be made is that early American metalworking cannot be represented as one cohesive style; metals played different roles in Incan society compared to Aztec society compared to North American society. In Meso-America and North America all metals utilized are understood to be found metals, that is, metals naturally occurring in their pure elemental state and not in an ore or oxide. The peoples of the Andes also primarily used found metals, especially for gold and silver, but evidence exists that they also possessed copper smelting technology . Indeed, the peoples that would become the Incas were quite possibly the most advanced metalworkers of the Americas, and produced works of considerable artistic merit. Mesoamericans metalworking technology was seemingly derived from that of the Andeans, as its appearance followed that of the Andeans and was similar in technique. No solid link has been found between the metallurgy of middle and South America, but natives in the north possessed some advanced techniques at least once. In the city of Cahokia, around 1200 A.D., a copper workshop is known to have existed which produced religious and ceremonial objects . While some trade existed north-south along the Americas, this communication was limited and resulted in highly localized styles and technologies, and the extent of this trade may never be known.
Many metalworking techniques present in Pre-Columbian America were very similar to those existent in the Old World, although obviously these processes were independently invented. Most metals were cold worked, which was a very reasonable way to work metals considering that the most common were found gold and silver. Although cold working was the dominant form of metallurgy, Indigenous Americans in the Andes and Columbia region developed casting processes for gold and silver jewelry, using the lost-wax method of casting . Alloys were also developed, including a copper/gold/silver alloy known to the Spanish as Tumbaga . Common to all these processes is that their ultimate goal is to produce an object of religious or ceremonial value. These techniques produced products of immense beauty and splendor, but of little use as a practical tool. This is understandable considering the malleability and softness of gold and silver, but begins to make less sense taking into account that early Americans had knowledge of copper working. Even more confusing is the abundance of Iron in the Andes Mountains, a metal that was never utilized prior to European colonization. The natives of the Americas possessed considerable metalworking skill, but never produced robust metal tools or weapons. The reasons behind this lack of development can only be speculated at, although with modern archeology and knowledge we may have a good guess.
There are many reasons why the early American people did not develop metallurgy along the Eurasian path. These include the size and geography of the Americas, the time allowed for development, and the cultural role metals played in each hemisphere. The population of the Americas was considerably less than that of Eurasia during the period the art of metallurgy developed, limiting the variety of societies that existed and diminishing the probability that a new discovery would be made by some accident or stroke of genius. Eurasia also benefits from an east-west axis, allowing ideas, goods, and animals to be traded across similar climates for thousands of miles. The Americas, however, were constricted by their primarily north-south axis; trade had to be conducted across many different climes, preventing the spread of useful kinds of agriculture and metallurgy from south to north. Eurasia also benefited from being continuously inhabited by humans for hundreds of thousands of years, modern humans only fully colonized the Americas approximately as late as 15,000 years ago . Finally, the cultural role of metals in indigenous society most likely inhibited the use of metals for anything more than a religious object or status item. To the Incas in particular, the appearance of a metal was its most important quality. Special cold working techniques were developed including a process involving hammering a copper-gold alloy to create a thin layer of almost pure gold on the outside . Incredible works of art were created, including a bust only one inch tall but composed of twenty-two separate gold plates expertly joined together .
It is apparent to the modern historian that despite stereotypes of Native Americans as backwards savages, indigenous peoples in fact possessed considerable metalworking skill. This industry was based around cold working found gold and silver into jewelry and sacred artifacts, although advanced processes including smelting, alloying, and lost-wax casting are known to have exist. While the original inhabitants of the Americas were not able to progress into an age of bronze or iron weapons and tools before European colonization, it is possible if not likely that this would have occurred given enough time. Many facets of early American metalworking remain yet to be discovered; perhaps future archeological research will provide more insight into the question of Pre-Columbian metalworking.
 - Mann, Charles C, 1491: New Revelations of the Americas Before Columbus. New York, New York: Random House, 2011
 - Keatinge, R.W., Peruvian Prehistory: An Overview of Pre-Inca and Inca Society, Cambridge University Press, 1988