The Ancient History of Copper
Copper is considered to be one of the first metals to be used by humans. The main reason for its early discovery and use is that copper can naturally occur in relatively pure forms.
Although various copper tools and decorative items dating back as early as 9,000 BC have been discovered, archaeological evidence suggests that it was the early Mesopotamians who, around 5000 to 6000 years ago, were the first to fully harness the ability to extract and work with copper.
Lacking modern knowledge of metallurgy, early societies, including the Mesopotamians, Egyptians and Native Americans, prized the metal mostly for its aesthetic qualities, using it like gold and silver for producing decorative items and ornaments.
The earliest organized production and use of copper in different societies have been roughly dated as:
- Mesopotamia, circa 4500 BC
- Egypt, circa 3500 BC
- China, circa 2800 BC
- Central America, circa 600 AD
- West Africa, circa 900 AD
Regular Use of Copper
Researchers now believe that copper came of regular use for a period — referred to as the 'Copper Age' — prior to its substitution by bronze. The substitution of copper for bronze occurred between 3500 to 2500 BC in West Asia and Europe, ushering in the Bronze Age.
Pure copper suffers from its softness, making it ineffective as a weapon and tool. But early metallurgy experimentation by the Mesopotamians resulted in a solution to this problem: bronze. Bronze, an alloy of copper and tin, was not only harder but also could be treated by forging (shaping and hardening through hammering) and casting (poured and molded as a liquid).
The ability to extract copper from ore bodies was well-developed by 3000 BC and critical to the growing use of copper and copper alloys. Lake Van, in present-day Armenia, was the most likely source of copper ore for Mesopotamian metalsmiths who used the metal to produce pots, trays, saucers and drinking vessels. Bronze and copper alloy tools, including chisels, razors, harpoons, arrows, and spearheads have all been discovered that date to the 3rd millennium BC.
A chemical analysis of bronze from the region indicates that common alloys of the time contained approximately 87 percent copper, 10 to 11 percent tin and small amounts of iron, nickel, lead, arsenic, and antimony.
Copper in Egypt
In Egypt, the use of copper was also developing around the same period, although there is nothing to suggest any direct knowledge transfer between the two civilizations. Copper tubes for conveying water were used in the Temple of King Sa'Hu-Re in Abusir built around 2750 BC. These tubes were produced from thin copper sheets to a diameter of 2.95 inches (75mm), while the pipeline was nearly 328 feet (100m) in length.
The Egyptians also used copper and bronze for mirrors, razors, instruments, weights, and balances, as well as the obelisks and adornments on temples.
According to biblical references, massive bronze pillars, measuring 6 feet (1.83m) in diameter and 25 feet (7.62m) tall once stood upon the porch of King Solomon's Temple in Jerusalem (circa 9th century BCE). The interior of the temple, meanwhile, is recorded as containing the so-called 'Brazen Sea,' a 16,000-gallon bronze tank held aloft by 12 cast bronze bulls. New research suggests that copper for use in King Soloman's temple could have come from Khirbat en-Nahas in modern-day Jordan
The Near East and Copper
Copper and, in particular, bronze items spread throughout the near east and pieces from this period have been uncovered in modern-day Turkey, Iran, Greece, and Azerbaijan.
By the 2nd millennium BC, bronze items were also being produced in large quantities in areas of China. Bronze castings found in and around the provinces of Henan and Shaanxi are considered the beginning of China's bronze, although some copper and bronze artifacts used by the Majiayao have been dated as early as 3000 BC.
Literature from the era shows how developed Chinese metallurgy was, with detailed discussions of the exact proportion of copper and tin used to produce different alloy grades used for casting different items, including cauldrons and bells, axes, spears, swords, arrows, and mirrors.
Iron and the End of the Bronze Age
While the development of iron smelting put an end to the Bronze Age, the use of copper and bronze did not stop. In fact, under the Roman's expanded the use for, and extraction of, copper. The Romans engineering ability lead to new systematic extraction methods that particularly focused on gold, silver, copper, tin, and lead.
Previously local copper mines in Spain and Asia Minor began to serve Rome, and as the empire's reach broadened more mines were integrated into this system. At its peak, Rome was mining copper as far north as Anglesey, in modern day Wales, as far east as east as Mysia, in modern Turkey, as far west as far west as the Rio Tinto in Spain, and could produce up to 15,000 tons of refined copper per annum.
Part of the demand for copper came from coinage, which had begun when Greco-Bactrian kings issued the first copper-containing coins around the third century BC. An early form of cupronickel, a copper-nickel alloy, was used in the first coins, but the earliest Roman coins were comprised of cast bronze bricks adorned with the image of an ox.
It is believed that brass, an alloy of copper and zinc, was first developed around this time (circa 3rd century BC), while its first use in widely circulated coinage was in Rome's dupondii, which were produced and circulated between 23 BC and 200 AD.
It is not surprising that the Romans, given their extensive water systems and engineering ability, made frequent use of copper and bronze in plumbing related fittings, including tubing, valves, and pumps. The Romans also used copper and bronze in armor, helmets, swords, and spears, as well as decorative items, including brooches, musical instruments, ornaments, and art. While the production of weapons would later shift to iron, decorative and ceremonial items continued to be made from copper, bronze, and brass.
As Chinese metallurgy led to different grades of bronze, so did Roman metallurgy develop new and varying grades of brass alloys that had varying ratios of copper and zinc for particular applications. One legacy from the Roman-era is the English word copper. The term copper is derived from the Latin word cyprium, which appears in early Christian-era Roman writing and was likely derived from the fact that much Roman copper originated in Cyprus.
Reardon, A.C. (Editor). Metallurgy for the Non-Metallurgist. Second Edition. ASM International (2011).
Smith, B. Webster. Sixty Centuries of Copper. UK Copper Development Association (1965)
Copper Development Association Inc. History of Copper.
Science Daily. "King Soloman's Copper Mines?" October 28, 2008.