The development of civilization has relied heavily on the discovery of metals. Prehistoric man used metals to build tools and weapons and as our knowledge of metal has developed, they have played an essential role in the advancement of agriculture, transport and arts and crafts – forging the path to today’s modern society.
The earliest recorded metal employed by humans appears to be gold.
GOLD
Gold, chemical symbol Au (the Latin word meaning ‘shining dawn’), is a precious metal which has been used since antiquity in the production of jewellery, coinage, sculpture, vessels and as a decoration for buildings, monuments and statues.
Gold does not corrode and so it became a symbol of immortality and power in many ancient cultures. Its rarity and aesthetic qualities made it an ideal material for ruling classes to demonstrate their power and position. Gold was first found at surface level near rivers in Asia Minor.
A gold bead found in France 2200-2000 BCE.
Gold occurs alone or in a mixture with other ores. It is soft and easily worked, and does not react chemically in most circumstances. It is largely immune from tarnishing or other surface deterioration.
From earliest times gold has been considered to be “incorruptible,” and has been treasured as much for that (and the associated symbolism) as for its comparative rarity and its surface glitter.
However gold is quite soft, and gold objects are accordingly rather weak. Therefore it is usually either alloyed with other metals (such as copper) or used as a surface covering on objects made of sturdier (and cheaper) material.
Gold hammered into thin sheets can be pressed or pounded over or into a mold to produce a bas-relief design, a process known as repoussé.
GOLD JEWELLERY
In most ancient cultures gold was popular in jewellery and art because of its value, aesthetic qualities, and malleability. Gold jewellery took the form of necklaces, bracelets, earrings, rings, pendants, pins and brooches.
Gold bracelet in the form of a coiled snake, 1st Century AD, Roman, Pompeii
Currency
Gold was first used as coinage in the late 8th century BCE in Asia Minor. The first coins were irregular in shape and often had only one side stamped. The first pure gold coins with stamped images are credited to king Croesus of Lydia, 561-546 BCE.
Even the purest naturally occurring gold can contain 5% silver but the Lydians were able to refine their gold using salt and high temperatures. The salt mixed with the silver and formed a vapor of silver chloride leaving behind pure gold which could be used to create standardized coinage of guaranteed gold content.
The Mycenaean civilization widely used gold coins, as did the later Greek and Roman Empires, although silver was the more usual material used.
Macedonian gold coin 359-356 BCE. The Front side depicts the Head of Apollo. and the back side depicts a Charioteer.
Religious Artifacts & Other Uses
The value and beauty of solid gold made it an ideal material for particularly important political and religious objects such as crowns, scepters, symbolic statues, libation vessels and votive offerings.
Gold items were sometimes buried with the dead as a symbol of the deceased’s status. Perhaps the most famous example is the so-called mask of Agamemnon found at Mycenae.
Mask of Agamemnon, 1550–1500 BC, Gold
The Mask of Agamemnon is an artifact discovered at Mycenae in 1876. The artifact is a funeral mask crafted in gold, and was found over the face of a body located in a burial shaft. The body was believed to be that of he legendary Greek leader Agamemnon, but modern archaeological research suggests that the mask is from 1550–1500 BC, earlier than the life of Agamemnon.
The mask of Agamemnon was created from one thick gold sheet, heated and hammered against a wooden background with the details chased on later with a sharp tool.
Gold in the Inca civilization of Peru gold was considered the sweat of the sun god and was used to manufacture all manner of objects of religious significance, especially masks and sun disks.
In ancient Colombia, gold was similarly revered for its luster and association with the sun and in powdered form was used to cover the body of the future king in a lavish ceremony which gave rise to the legend of El Dorado.
As a decorative covering, gold plate and gold leaf (gold beaten into extremely thin sheets) have been used to decorate shrines, temples, tombs, sarcophagi, statues, ornamental weapons and armor, ceramics, glassware and jewellery since Egyptian times. Perhaps the most famous example of gold leaf from antiquity is the death mask of King Tutankhamun.
Death Mask of Tutankhamun, 1332–1323 BC Gold
Gold, with its malleability and incorruptibility, has also been used in dental work for over 3000 years. The Etruscans in the 7th century BCE used gold wire to fix in place substitute animal teeth. As thread, gold was also woven into fabrics. Gold has even been used in ancient medicine.
Copper
The use of copper in antiquity is of more significance than gold. The first tools, implements and weapons were made from copper. From 4,000 to 6,000 BC is the period copper first came into common use. The symbol for copper is Cu and comes from the latin cuprum meaning from the island of Cyprus. Initially copper was chipped into small pieces from the main mass. The small pieces were hammered and ground in a manner similar to the techniques used for bones and stones.
However, when copper was hammered it became brittle and would easily break. The solution to this problem was to anneal the copper. Which means to heat it and allow it to cool slowly, in order to remove internal stresses and toughen it. This discovery was probably made when pieces were dropped in camp fires and then hammered. By 5,000 BC copper sheet was being made.
By 3600 BC the first copper smelted artifacts were found in the Nile valley and copper rings, bracelets, chisels were found. By 3000 BC weapons, tools etc. were widely found. Tools and weapons of utilitarian value were now within society, however, only kings and royalty had such tools; it would take another 500 years before they reached the peasants.
Early Copper Axe Replica
Malachite, a green friable stone, was the source of copper in the early smelters. Originally it was thought that the smelting of copper was by chance dropping of malachite into campfires. However, campfire temperatures are normally too low for reduction. It is more probable that early copper smelting was discovered by ancient potters whose clay firing furnaces could reach temperatures of 1100-1200 C. If Malachite was added to these furnaces copper nodules would easily be found. The first smelted copper was produced first in Western Asia between 4000 and 4300 BC.
Although copper can be found free in nature the most important sources are the minerals cuprite, malachite, azurite, and bornite. Copper is reddish colored, malleable, ductile and a good conductor of heat and electricity. Approximately 90% 0f the worlds primary copper originates in sulfide ores.
A recent article (August 2014) has come out revealing that copper was definitely the oldest metal used by man. A copper awl is the oldest metal object unearthed to date in the Middle East. The discovery reveals that metals were exchanged across hundreds of miles in this region more than 6,000 years ago, centuries earlier than previously thought.
The artifact was unearthed in an archaeological site in Israel located near the Jordan River and Israel’s border with Jordan. The area was a village that dates from about 5100 B.C. to 4600 B.C., and was first discovered in 1950, with digs taking place from the end of the 1970’s up to the present day.
Archaeologists discovered the cone-shaped awl in the grave of a woman who was about 40 years old when she died. Several large stones covered the grave, which was dug inside a silo, suggesting both the woman and the silo were considered special.
The copper awl is about 1.6 inches long and about 0.2 inches wide at its base. It was set in a wooden handle, and since it was buried with her, the researchers suggest the awl may have belonged to the woman.
Before this discovery, the earliest pieces of evidence for metal use in the ancient Near East were found in the southern Levant and included copper artifacts from the Nahal Mishmar cave and gold rings found inside the Nahal Qanah cave dating from 4500 B.C. to 3800 B.C.
Zoomorphic Ibex, found in the Cave of the Treasure, Nahal Qanah, copper
The awl suggests people in the area started using metals as early as 5100 B.C., several centuries earlier than previously thought. Chemical analysis of the copper also revealed it probably came from about 620 miles away. This discovery suggests people in this area originally imported metal artifacts and only later created them locally.
THE BRONZE AGE
Bronze is an alloy consisting primarily of copper and other metals. The addition of other metals (usually tin, sometimes arsenic), produces an alloy much harder than plain copper. The historical period where many bronze artifacts are found is known as the Bronze Age.
Because historical pieces were often made of brasses (copper and zinc) and bronzes with different compositions, modern museum and scholarly descriptions of older objects increasingly use the term “copper alloy” instead.
The discovery of bronze enabled people to create metal objects which were harder and more durable than previously possible. Bronze tools, weapons, armor, and building materials such as decorative tiles were harder and more durable than their stone and copper predecessors. Initially, bronze was made out of copper and arsenic, forming arsenic bronze, or from naturally or artificially mixed ores of copper and arsenic.
It was only later that tin was used, becoming the major non-copper ingredient of bronze in the late 3rd millennium BC. Tin bronze was superior to arsenic bronze in that the alloying process could be more easily controlled, and the resulting alloy was stronger and easier to cast. Also, unlike arsenic, tin is not toxic.
The earliest tin-alloy bronze dates to a site in Serbia. Other early examples date to the late 4th millennium BC in Africa, Iran and some ancient sites in China, and Mesopotamia (Iraq).
Bronze Head Sculpture, Nigeria c. 12th century AD
Ewer from 7th-century Iran. Cast, chased, and inlaid bronze
Ores of copper and the far rarer tin are not often found together (exceptions include one ancient site in Thailand and one in Iran), so serious bronze work has always involved trade. Tin sources and trade in ancient times had a major influence on the development of cultures. In Europe, a major source of tin was England’s deposits of ore in Cornwall, which were traded as far as Phoenicia in the Eastern Mediterranean.
Picture of Life During the Bronze Age
Textile production was under way by this time and the dead were cremated, and buried in small cemeteries behind each settlement. The large burial sites were a thing of the past, as the land was now needed for agriculture.
The late Bronze Age was also known for advanced pottery making techniques, and more sophisticated weapon making. The Iron Age that followed it did not happen suddenly, but is thought to have started in Britain around 650 BC and finished around AD 43. The knowledge of iron making was brought about by Europeans, who had already started to build the first blast furnaces.
To sum up, the period of Bronze Age man lasted for almost 1,500 years, a time that took the giant step from the Stone Age to the Iron Age.
IRON AGE
The Iron Age is the period generally occurring after the Bronze Age, marked by the prevalent use of iron.
The adoption of iron coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles.
Ancient literature of the Iron Age includes the earliest texts preserved in manuscript tradition. Sanskrit and Chinese literature flourished in the Iron Age. Other texts include the oldest parts of the Hebrew Bible. The principal feature that distinguishes the Iron Age from the preceding ages is the development of written language.
Metalsmithing expanded to include forging during the Iron Age. Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer.
The system of decoration, went from repetition of rectilinear patterns to a system of curvilinear and flowing designs during the Iron Age.
The term “Iron Age” has low chronological value, because it did not begin simultaneously across the entire world. The dates and context vary depending on the region. There are areas, such as the islands of the South Pacific, the interior of Africa, and parts of North and South America, where peoples have passed directly from the use of stone to the use of iron without an intervening age of bronze.
The earliest known iron artifacts are nine small beads, dated to 3200 BC, from burials in northern Egypt. They were made from iron that had been shaped by careful hammering.
Photographs of three of the nine iron beads from Egypt.
Iron’s qualities, in contrast to those of bronze, were not understood at the time these beads were made.
Iron smelting (the extraction of usable metal from oxidized iron ores) is more difficult than tin and copper smelting. Tin and copper and their alloys can be cold-worked, or melted in simple pottery kilns and cast in molds; but smelted iron requires hot-working and can be melted only in specially designed furnaces.
BLAST FURNACES
The oldest blast furnaces were built in China in the 1st century BC. Early iron smelters employed an average workforce of over two hundred men. These early furnaces had clay walls and used phosphorus-containing minerals as a flux. Air was also added to further increase temperatures within the furnace. It is thought that early blast furnaces evolved from furnaces used to melt bronze.
In Europe, the blast furnace developed gradually over the centuries from small furnaces in which charcoal was used for reducing ore to a semisolid mass of iron containing a relatively small amount of carbon and slag.
The iron mass was then hammered to remove the slag, yielding wrought iron. Increases in the height of the furnace, coupled with mechanical bellows for introducing greater amounts of air into it, allowed the higher temperatures needed to produce a high-carbon iron known as cast, or pig, iron.
This mode of production was used in central Europe by the mid-14th century and was introduced into England about 1500. Charcoal was the only furnace fuel until the 17th century. The depletion of forests in England led to experiments with coke, which is produced from coal. Coke had been widely adopted for use in blast furnaces by the mid-18th century, and the principle of heating air before it entered the furnace was introduced in the early 19th century.
Examples of Iron Age Work
The Torrs Horns and Torrs Pony-cap, as displayed in 2011, Iron
The Torrs Horns and Torrs Pony-cap are Iron Age bronze pieces now in the National Museum of Scotland. The two were found together, but their relationship is questionable. Most scholars agree that horns were added to the pony-cap at a later date. These objects date to around 200 BC. It is generally agreed that the horns are from a later date than the cap, and were made in a different style. It is apparent that these pieces are very finely designed and skillfully executed. The Torrs Horns and Pony-Cap were commissioned by the elite of Iron Age society.
Description
The cap is decorated in repoussé with vegetal motifs, trumpet-spirals and bird heads, while the horns have “boldly asymmetric” engraved decoration including a human face and the single complete one terminates in a modeled bird head; it has been suggested that this represents specifically the head of a northern shoveller duck. This probably originally had coral eyes; the other horn lacks its tip. The cap has holes for the ears of the horse.
Brooch in the Shape of a Horse, 7th–6th century b.c.; Iron Age
This tiny brooch in the shape of a horse is one of a small group of central European animal pins that survive from the Iron Age. While some take the form of a stag or goat, all the pins are similar in that the animals are entirely three-dimensional, with the hind legs concealing the spring of the pin while the catch is attached to the forelegs. The horse remained an important shape for European brooches into the Celtic period, with numerous examples found in fifth-century graves. In prehistoric Europe, horses were difficult to obtain and expensive to maintain, thus making them important symbols of status and power. Perhaps brooches such as these were talismans (objects that are believed to bring good luck), their power deriving from their representation of this highly valued and venerated animal.
Lion head terminal, Iron Age II, 9th century b.c. found in Northwestern Iran
This powerful snarling lion has a slightly protruding tongue. The animal’s muzzle is wrinkled and solid spheres form the eyes. The object is one of a pair. It is cast solid in the form of a lion’s head, with a hollow cylindrical neck with four openings near the base and a solid tang below. When excavated, no other object or material was found near the pair to give a clue to their function, although they may have been placed on an article of furniture, perhaps at the top of the uprights of a chair.
METALS TIMELINE
HOW DID WE GET METALS ON EARTH?
Meteorites and asteroids from the inner solar system could be responsible for Earth’s store of precious metals such as platinum and iridium, brought to our planet about 4,000 million years ago.
Artz 363 