The development of human society has traditionally been divided into several parts. The Stone Age developed into the Bronze Age, where bronze processing replaced the stone tools and weapons previously used. The Iron Age also replaced the Bronze Age.
These advances are often thought of as progress from one metal to another, but they are not, and they also obscure the experiments that ancient blacksmiths conducted in search of better metals. This experiment could be fatal.
For a time, during the Bronze Age of the 5th millennium BC, the strongest and easiest metal to work on was "arsenic bronze". For a short period of time, this highly toxic material was the pinnacle of technology.
Metalworkers desperately searched for better alternatives, but the metals they worked on killed them before other technologies were developed.
origin
Traditionally, and most commonly, bronze is an alloy of copper and tin. However, Bronze Age metalworkers found that adding arsenic instead of tin resulted in a more processable final product with better casting properties.
Copper is usually contaminated with arsenic in any case, so when used in archaeology, the term arsenic bronze is usually only applied to alloys with arsenic content exceeding 1% by weight. This is a large amount of arsenic, a deadly poison that can be absorbed through the skin.
A knife made of bronze. The bottom knife is arsenic bronze and has a pronounced appearance
However, despite the dangers, arsenic bronzes appear in archaeological records around the world. The earliest known artifacts are found in the 5th millennium BC by the Iranians (including much of Central, South and West Asia). It's unclear whether arsenic was deliberately added to copper in all cases, but for some societies, it was definitely intentional.
Four possible methods may be used to produce arsenic bronze alloys. The first is by adding arsenic-containing metals to the molten copper, although this lacks conclusive evidence.
The reduction of copper arsenate is another method of processing materials, which produces an alloy of high arsenic and antimony. Co-smelting of oxidized ore and vulcanized ore, or reduced roasted copper thiogenesis, will also produce the ideal material, although the latter produces toxic fumes.
Exposure to arsenic, whether through smoke, absorption or contamination of arsenic dust, can have a significant impact on the mortality rate of metalworkers. However, this did not stop them, and the artifacts produced in these methods are highly complex. Ornaments of ornaments, axes, and arsenic bronzes have been preserved to this day.
Advantages of arsenic bronze
One of the main advantages of using arsenic bronze is that it reacts with oxygen, forming oxides that evaporate from liquid metals. When the metal cools, it separates in such a way that the metal deforms and works without breaking.
Second, alloys made in this way can be processed into a material that is harder than ordinary copper and easier to process than tin bronze. This means it performs better when used for cutting or shredding.
Evidence of this comes from the Caucasus between Europe and Asia, as well as in the Mexicans, where bells are made of copper.
Where did you find it?
Arsenic bronze is used in many societies and cultures around the world. From its first appearance on the Iranian plateau, it spread to ancient "Mesopotamia" in modern Iran, Iraq and Syria.
This region is the cradle of civilization and has the world's earliest bronze metallurgy. From the 4th millennium BC to at least the middle of the 2nd millennium BC, it was found in use.
At the end of the Gris and Euphrates rivers around the Ur Akadian and Amoritic societies, throughout the Bronze Age, the use of this metal spread throughout the Middle East. It spread from the Jewish desert near the Dead Sea to the entire Levant, driving technological development throughout the region.
A ceremonial dagger made of arsenic bronze, the Lambayek Tummi culture
The use of arsenic bronze also spread from the northwest along trade routes eastward from China to the Ganqing region. However, it is unclear whether the artifacts were imported or manufactured locally.
It is more likely that the bronzes here were built through local mining of mineral resources. In contrast, the arsenic bronzes found here bear similarities with the Eurasian steppes.
Archaeological records come from distant regions such as Egypt, the Caucasus and Peru. It is shown that arsenic bronze is used with tin bronze. In some areas, the continued use of this dangerous substance continued even into the Iron Age, where it was used to make trinkets and decorative items.
In most cases, however, the use of arsenic bronze is likely to be phased out over time. Tin bronze, while not so easy to process, is far less dangerous and is still popular in some areas.
Bronze: Magical material
The discovery of bronzes completely changed society. Bronze tools, weapons, armor, and building materials lasted much longer than their stone predecessors and could be melted down and used again and again.
In many parts of the world, a large number of hoarded bronzes have been found, which means that bronzes have been valued by historians. It may even be an indicator of social status. In Europe, for example, a large number of bronze tools, such as socket axes, have been found, showing no signs of wear and tear, and were the most precious tools of that period at that time.
Bronze was originally used to produce weapons; however, it was soon used by metalworkers to produce works of art. The most common method of making bronze sculptures is through the lost-wax process. This creates a unique form of hollow sculpture mold.
A fatal period in history
The ancients must have known about the dangers of arsenic bronze and the lethal trade-off it represented. It produces a hard, durable material that can be used to make tools, weapons, and decorative pieces. But it kills people who work.
Mediterranean bronzes from the early Bronze Age
Tin bronze may be more difficult to machine, but it can eventually produce alloys that resemble solids without creating another deadly dangerous metal. So arsenic bronze is a shortcut, a metal that a less skilled blacksmith can use, but at what cost?
To be sure, many cultures are prepared to take this risk. As a material, bronze is a key element of modern social development. And arsenic bronze, the deadly metal of the Bronze Age, played an important role in this development.