Tumbaga – The Real Aztec Gold?
Gold has always been the stuff of legends, with rumours and stories of large caves filled with treasure, or chests buried in remote islands by cutthroat buccaneers. Due to the valued status of gold to many individuals and cultures throughout history, it has been fought for, coveted, and hidden in the hopes of claiming a hold on the pinnacle of glory that can be bought or traded for by the yellow commodity. One of the most interesting finds with regards to treasure is the ancient gold alloy known as tumbaga. Tumbaga is an alloy of gold and copper developed by early Mesoamericans for ritualistic and religious purposes. Once common in pre-Columbian Mesoamerica and some parts of Mexico, tumbaga was once the most common metallic material employed for a variety of different purposes, with the majority of tumbaga items especially reserved for community rituals and religious rites.
Composed of varying amounts of gold, silver and copper, tumbaga has a relatively low melting point and, like pure gold, it was extremely malleable and could be pounded into a wide variety of different shapes. Some items made of tumbaga were even used as personal accessories or as ritual accoutrements, making them (perhaps) the fables golden items of the Mayan priesthood replete in many legends. The allure of tumbaga lay in the fact that when observed by the naked eye, it appears as a solid item of pure gold. The ancient Mesoamericans who developed the tumbaga alloy unwittingly created a process to create an object that was seemingly created from pure gold, despite it being a composite alloy consisting mainly of copper and a decent amount of silver and / or gold. This created the illusion of immense wealth which drew many of the western conquerors to pillage and later sack many of the ancient civilizations of Mexico.
Nowadays, modern metallurgists have discovered that tumbaga can be ‘purified’ to its pure gold state with the use of an acid solution which dissolves the copper on the surface, revealing the pure gold that lies underneath. This method, known as depletion gilding, can be a tricky one, as not all items made from tumbaga contain considerable amounts of gold. The ancients knew of this process, and used their own acid solution made from citric acid and salt to dissolve the tumbaga’s surface layer to reveal the rich, golden metal underneath. Whether the ancient Mayans or Aztecs knew that gold and copper were two distinctly different metals is not known, but some pieces of tumbaga that have undergone depletion gilding have come up with either 97% gold, or nothing more than 97% copper with only trace amounts of gold. Despite the seemingly deceptive appearance of tumbaga, the fact that it showed excellent workmanship, and that it looked in every respect like pure gold, it became the fuel that fired an onslaught that later decimated many ancient Mesoamerican civilizations in a play of deceit, fire and blood that elicited the fall of several empires.
For all of the craftsmanship that some examples of tumbaga showed, the conquistadors that plundered the wealth of the Mesoamericans took very little notice of the workmanship and hastily melted their stolen wealth into bars to be shipped to their lieges. Evidence of this seeming desecration can be found in the tumbaga wreck discovered in the Grand Bahama Island in 1992 was an example. Today, exemplary pieces of tumbaga are rare and highly prized, not only due to its inherently valuable composition, but due to the history behind the treasure.
Tumbaga – References:
 "Metals in MesoAmerica" - http://nephiproject.com/Newsletter/Metals%20in%20Mesoamerica.doc
Content researched and created by Alexander Leonhart for coinandbullionpages.com/gold-alloys © coinandbullionpages.com/gold-alloys 2012