Gold does not corrode, so it became a symbol of immortality and power in many ancient cultures. Its rarity and aesthetic quality make it an ideal material for the ruling class to show its power and status. Gold was first discovered on the surface near rivers in Asia Minor, such as the Pacteau River in Lydia. In 2000 BC, Egyptians and later Romans began to mine gold underground in Africa, Portugal and Spain. There is also evidence that the Romans smelted gold particles from pyrite and other ores. Gold is easy to process and mixed with other metals such as silver and copper to increase its strength and change its color, so it is used for many purposes.
gemstone
In most ancient cultures, gold is popular in jewelry and works of art because of its value, aesthetic quality, ductility and ductility. Since 5000 BC, Egyptians have used silver and gold mines (natural alloys of gold and silver) to make jewelry. Gold jewelry was made by men and women in Sumerian costumes in the first city of Ur around 2500 BC. At the beginning of Minoan civilization in Crete in the 2nd century BC, people thought that the first producer of anchor chain jewelry came from Minos, and Minos used a wide range of techniques to make a large number of jewelry. Gold jewelry takes the form of necklaces, bracelets, earrings, rings, crowns, pendants, pins and brooches. Techniques and shapes include filigree (known to the Egyptians as early as 2500 BC), in which gold is drawn into silk and twisted into different designs, thinned, granulated (the surface is decorated with small, welded gold particles), embossed, chased, inlaid, shaped and carved. In South America, around 1200 BC, Chavin Wenming of Peru processed gold in a similar way, and the Nazca people perfected the gold casting process in 500 BC. The Romans used gold as a setting for precious stones and semi-precious stones, and this fashion continued until the Byzantine era, using pearls, precious stones and enamel.
The value and beauty of gold make it an ideal material for particularly important political and religious items.
money
In the late 8th century BC, gold was first used as a coin in Asia Minor. Coins are irregular in shape and usually have only one seal, usually made of gold and silver. The first image printed with pure gold coins was deposited in King Shen Dianxia, crois, and Saldis was excavated in the capital in 56 BC1-546 BC and the contemporary gold refinery. Even the purest natural gold may contain 5% silver, but Lydians can use salt and a furnace of 600 to 800 degrees Celsius to extract gold. Salt and silver are mixed to form silver chloride vapor, leaving pure gold, which can be used to make standardized coins to ensure the gold content. Gold coins were also widely used in Mycenae civilization and later in the Greek and Roman empires, although silver was the more commonly used material. One of the most famous gold coins in ancient times was the Besant of Rome. It was first introduced during the reign of Constantine the Great, weighing 70 Jin, and circulated from the 4th century to12nd century.
Religious cultural relics and other uses
The value and beauty of pure gold make it an ideal material for making particularly important political and religious objects, such as crowns, scepters, symbolic statues, wine vessels and offerings. Gold products are sometimes buried with the dead. As a symbol of the identity of the dead, ostentatiously (and unprofitable) consuming this rare and precious material is absolutely to impress people. Perhaps the most famous example is the so-called Agamemnon mask found in Mycenae. In the Inca civilization of Peru, gold was regarded as the sweat of Inti, the sun god, so it was used to make various religious objects, especially masks and solar discs. In ancient Colombia, gold was also revered for its luster and connection with the sun. In the luxurious coronation ceremony, gold was covered with powder on the body of the future king, which gave birth to the legend of Huang Jinguo.
Since Egyptian times, gold plating and gold foil (gold is beaten into extremely thin sheets) have been used as decorative coverings to decorate temples, temples, tombs, sarcophagus, statues, decorative weapons and armor, ceramics, glassware and jewelry. Perhaps the most famous example of ancient gold foil is King Tutankhamun's death mask.
Gold is malleable and non-corrosive, and has been used in dental work for more than 3000 years. In the 7th century BC, Etruscans fixed the teeth of substitute animals in place with gold thread. As thread, gold is also woven into fabric. Gold is also used in medicine. For example, Pliny suggested in BC 1 century that gold should be applied to wounds as a defense against "magic potion".
Gold grading
Concerns about the authenticity of gold led the Egyptians to design a method to determine the purity of gold around 1500 BC (or earlier). This method is called fire assay, which includes taking a small sample from the test material and firing it in a small crucible with a certain amount of lead. Crucibles are made of ashes, which will absorb lead and any other base metals during firing, leaving only gold and silver. Silver was removed by nitric acid, and the remaining pure gold was weighed and compared with the weight before firing. Archimedes also realized that the specific gravity of gold will change according to the percentage content of base metals, for example, the specific gravity of pure gold is twice that of silver.
Gold is such a precious material. For centuries, people have made various attempts through alchemy, that is, using lapis lazuli philosophy to chemically transform base metals into gold. The first attempt was made in China and ancient Greece in the 4th century BC. Although unsuccessful, this activity laid the foundation of modern chemistry.