copper
Copper (Cuprum) is a metallic element and also a transition element. Its chemical symbol is Cu, and its English name is copper. Its atomic number is 29. Pure copper is a soft metal. When the surface is just cut, it is red-orange with a metallic luster. The single substance is purple-red. It has good ductility, high thermal conductivity and electrical conductivity. Therefore, it is the most commonly used material in cables and electrical and electronic components. It can also be used as a building material and can form many kinds of alloys. Copper alloys have excellent mechanical properties and very low resistivity. The most important ones are bronze and brass. In addition, copper is also a durable metal that can be recycled many times without damaging its mechanical properties.
Divalent copper salts are the most common copper compounds. Their hydrated ions are often blue, while chlorine as a ligand is green. It is the source of the color of minerals such as azurite and turquoise. It has been widely used as a pigment in history. Copper building structures will produce verdigris (basic copper carbonate) after corrosion. Decorative art mainly uses metallic copper and copper-containing pigments.
Copper is one of the earliest metals used by humans. As early as prehistoric times, people began to mine open-pit copper mines and use the copper they obtained to make weapons, tools and other utensils. The use of copper had a profound impact on the progress of early human civilization. Copper is a metal that exists in the earth's crust and the ocean. The content of copper in the earth's crust is about 0.01%, and in some copper deposits, the content of copper can reach 3% to 5%. Most of the copper in nature exists as compounds, namely copper ores.
Copper has weak activity, and the reaction of iron with copper sulfate can replace copper. Copper is insoluble in non-oxidizing acids.
Humans have been using copper and its alloys for thousands of years. In ancient Rome, the main mining area for copper was Cyprus, so it was originally named cyprium (meaning metal from Cyprus), and later became cuprum, which is the source of its English (copper), French (cuivre) and German (Kupfer).
Copper is one of the earliest metals used by humans. As early as prehistoric times, people began to mine open-pit copper mines and use the copper they obtained to make weapons, tools and other utensils. The use of copper had a profound impact on the progress of early human civilization.
China has a long history of using copper. About six or seven thousand years ago, the ancestors of the Chinese discovered and began to use copper. In 1973, a semicircular copper fragment was unearthed at the Jiangzhai site in Lintong, Shaanxi, which was identified as brass. In 1975, a bronze knife was unearthed at the Majiayao cultural site in Linjia, Dongxiang, Gansu (about 3000 BC). This is the earliest bronze artifact discovered in China and is proof that China entered the Bronze Age. Compared with West Asia, South Asia and North Africa, which entered the Bronze Age about 6,500 years ago, the Bronze Age in China came later. There was an era in China when bronze and stone tools were used together, dating back about 5,500 to 4,500 years. On this basis, China invented bronze alloys, which is the same as the development model of bronze in the world.
"The most important affairs of a country are sacrifices and wars." For the countries in the Central Plains of China before the Qin Dynasty, the biggest things were sacrifices and foreign wars. Bronze, which represented the most advanced metal smelting and casting technology at the time, was also mainly used in sacrificial rituals and wars. The bronzes discovered in the Xia, Shang and Zhou dynasties were all used as ceremonial utensils and weapons and their accessories, which was different from the bronzes in various countries in the world, forming a bronze cultural system with Chinese traditional characteristics.
The development of Chinese bronze culture is generally divided into three stages, namely the formation period, the heyday and the transition period. The formation period refers to the Longshan era, 4500-4000 years ago; the heyday is the Chinese Bronze Age, which includes the Xia, Shang, Western Zhou, Spring and Autumn, and the early Warring States period, which lasted for about 1,600 years, that is, the Bronze Culture Age of the traditional Chinese system; the transition period refers to the late Warring States period to the Qin and Han dynasties, when bronzes were gradually replaced by irons. Not only did the number of bronzes decrease, but they also changed from the original ritual weapons and used in ritual sacrifices, war activities and other important occasions to daily utensils. The corresponding types of instruments, structural characteristics, and decorative arts also underwent a turning point.
Formation period
The Longshan era, 4500-4000 years ago, is equivalent to the legendary era of Yao, Shun, and Yu. Ancient documents record that people had begun to smelt bronze at that time. In the Longshan era sites in the middle and lower reaches of the Yellow River and the Yangtze River, bronze products were found in dozens of sites through archaeological excavations. From the existing materials, the bronzes in the formation period have the following characteristics:
1. Red copper and bronze coexist, and brass appears. A bronze knife cast in a mold was unearthed at the Linjia site in Dongxiang, Gansu Province; two red copper plaques with holes were found at the Dachengshan site in Tangshan, Hebei Province; a bronze container fragment containing 7% tin was unearthed in the Longshan City of Wangchenggang, Dengfeng, Henan Province; a complete copper bell, tied with red copper, was unearthed in the Taosi cemetery in Xiangfen, Shanxi Province; two brass cones were unearthed at the Sanlihe site in Jiaoxian, Shandong Province; and brass fragments were unearthed in Yangjiaquan, Qixia, Shandong Province. The Qijia culture in Gansu, Qinghai and Ningxia has the largest number of copper products. Knives, cones, drills, rings and bronze mirrors were unearthed in several cemeteries, some of which are bronze and some are red copper. In terms of production technology, some are forged and some are cast in molds, which are relatively advanced.
2. There are fewer varieties of bronze ware, most of which belong to daily tools and life categories, such as knives, cones, drills, rings, bronze mirrors, decorations, etc. However, it should be acknowledged that people were able to make containers at that time. In addition, red or yellow pottery goblets are common in the Longshan culture, and the mouth and crotch often have imitation metal rivets. If it is believed that the copper goblets at this time have the same function as the copper goblets, jue and jia containers of the Xia and Shang dynasties, the bronze ware at that time had already or began to turn to ritual vessels.
3. Copper products were also unearthed in general small sites, and ordinary residents also owned bronze products. In addition, most of the bronze products of this period were plain and undecorated. Even the bronze mirrors with patterns were only geometric decorations such as star stripes and triangle patterns, without the mystery of the bronze decorations of the Three Dynasties.
Heyday
The heyday is the Chinese Bronze Age, including the Xia, Shang, Western Zhou, Spring and Autumn, and the early Warring States, which lasted for about 1,600 years. The bronze ware of this period is mainly divided into ritual instruments, weapons and miscellaneous instruments. Musical instruments are also mainly used in ancestral temple sacrifices. Ritual vessels are used in the cumbersome rituals of ancient times, or displayed in temples, or used for banquets and washing, and some are specially used as funeral objects. Bronze ritual vessels have a certain sacredness and cannot be used in ordinary life occasions. Among all bronzes, ritual vessels are the most numerous and the most exquisitely made. Ritual instruments can represent the highest level of Chinese bronze craftsmanship. Ritual vessels include cooking utensils, food utensils, wine vessels, water vessels and statues of gods. The bronzes of this period are the most exquisitely decorated and have a wide variety of decorations.
Decoration of bronzes
One of the most common patterns on bronzes is the Taotie pattern, also known as the animal face pattern. This pattern first appeared on the jade artifacts of the Liangzhu culture in the lower reaches of the Yangtze River 5,000 years ago, and the Shandong Longshan culture inherited this pattern. The Taotie pattern itself has a strong mysterious color. The "Lüshi Chunqiu·Xianshi" chapter says: "The Zhou tripod has a Taotie with a head but no body. It eats people but does not swallow them, and harms its body." Therefore, this animal face pattern is generally called the Taotie pattern. The Taotie pattern already existed on bronzes in the Erlitou Xia culture. There are many types of Taotie patterns in the Shang and Zhou dynasties, some of which look like dragons, tigers, cows, sheep, and deer; some look like birds, phoenixes, and people. In the Western Zhou Dynasty, the mysterious color of bronze decorations gradually faded. Dragons and phoenixes are still the main themes of many bronze patterns. It can be said that many patterned patterns are actually derived from the two major types of dragon and snake and phoenix and bird patterns.
Cicada patterns are common patterns in the Shang and Western Zhou dynasties. In the Spring and Autumn Period, there are also deformed cicada patterns. In the Spring and Autumn Period, the dragon pattern was popular and gradually occupied a dominant position, almost squeezing out other patterns. Another feature of Chinese bronzes is that no portraits have been found so far. Many bronzes use human faces as decorations, such as human-faced square tripods and human-faced axes, but these human faces are not the faces of any specific people. More artifacts are the overall image of a person, such as a human-shaped lamp or holder; or the whole person is used as part of the artifact, such as a bell frame with a sword-carrying figure holding up the horizontal beam with his hands, and several human-shaped feet under the copper plate. Most of these figures are dressed as male and female attendants, and they are not portraits of specific servants. The three-dimensional images and human heads unearthed in Sanxingdui, Guanghan, Sichuan, are larger than normal people, with long ears and protruding eyes, high noses and wide mouths, full of mystery, and should be mythical figures.
Tens of thousands of bronzes in the Shang and Zhou dynasties have inscriptions, which are generally called bronze inscriptions. For historians, they play a role in verifying and supplementing history.
The inscriptions on Chinese bronzes are mostly cast. The concave characters are called Yinwen, and a few characters are raised, called Yangwen. In the Shang and Western Zhou dynasties, it can be said that the inscriptions were all cast, with only a few examples of characters engraved with sharp tools.
In the late Western Zhou Dynasty, completely engraved inscriptions began to appear. In the middle of the Warring States Period, most inscriptions were already carved. Even the three extremely solemn ritual vessels in the Han Tomb of King Zhongshan in Pingshan, Hebei Province were carved with chisel, and the knife skills were extremely mature and had high artistic value.
Another outstanding feature of ancient Chinese bronzes is the exquisite craftsmanship, which shows the ingenious creativity of ancient craftsmen. The method of casting bronzes with ceramic composite molds was fully developed in ancient China. The selection of materials, molds, and patterns of ceramic molds were extremely sophisticated, and the techniques of solid casting, split casting, casting joints, and stacking casting were very mature. The subsequent development of the lost wax process technology without split casting was undoubtedly a major advancement in bronze casting technology. The ancients believed that bronzes were extremely strong and inscriptions could be passed down forever, so things that were to be passed down for a long time must be cast on bronze objects. Therefore, inscriptions have become an important material for studying ancient history today.
The technology of inlaying bronzes to increase their beauty appeared very early. The first type of inlay material is turquoise, a green gem that is still used in jewelry today. The second type is jade, including jade-backed spears, jade-leafed spears, jade-bladed axes, etc. The third type is meteorite iron, such as iron-bladed copper axes and iron-backed copper blades. After identification, the iron blades are all meteorite iron. The fourth type is inlaid red copper, which is used to form animal-shaped patterns. During the Spring and Autumn Period and the Warring States Period, there were also bronzes inlaid with gold and silver for decoration.
Smelting of bronze ware
In the Eastern Zhou Dynasty, the smelting technology was highly developed, and the technical summary document "Kaogongji" for making bronze ware appeared. The book made detailed regulations on the proportion of copper and tin in the bronze used to make various utensils such as bells, tripods, axes, and halberds. Due to frequent wars, weapon casting has developed rapidly. In particular, the swords of Wu and Yue were extremely sharp and famous all over the world. Some famous sword-casting craftsmen appeared, such as Gan Jiang and Ou Yezi. Although some swords have been buried underground for more than 2,000 years, they can still cut stacks of paper. Some swords, such as the Sword of Goujian, King of Yue, have undergone certain chemical treatments on their surfaces to form rust-proof diamond, scale-shaped or flame-shaped patterns, which are extremely gorgeous.
Transition period
The transition period generally refers to the period from the end of the Warring States Period to the end of the Qin and Han Dynasties. After hundreds of years of annexation wars and political, economic, and cultural reforms aimed at enriching the country and strengthening the army, the county system replaced the feudal system, and a centralized feudal society was finally established. The traditional etiquette system has completely collapsed, and iron products have been widely used. All areas of society have undergone earth-shaking changes.
The status of bronze ware in social life has gradually declined, and most of the utensils have become daily necessities, but when it comes to certain bronze ware, there are still many exquisite works. For example, the two bronze chariots and horses unearthed from the Mausoleum of Qin Shihuang in Lintong, Shaanxi. The first one was driven by four horses, with a canopy on the chariot and the driver sitting. Both chariots and horses are made of bronze castings, which are proportional to the actual size and extremely exquisite. There are also many gold and silver ornaments on the chariots and horses, and the whole body is painted. The second horse, 3.17 meters long and 1.06 meters high, can be said to be the largest and most complex bronze ware excavated so far.
By the end of the Eastern Han Dynasty, ceramics had developed significantly and played an increasingly important role in social life, thus further squeezing out daily bronze utensils from life. As for weapons and tools, iron had already dominated at that time. The bronze wares of the Sui and Tang dynasties were mainly various exquisite bronze mirrors, which generally had various inscriptions. Since then, bronze wares, except for bronze mirrors, have not developed much.
