There is a very interesting phenomenon in the history of the development of human civilization, that is, first experience the Bronze Age, and then experience the Iron Age.
Why did the Bronze Age predate the Iron Age? Or why is it that the first metal humans used was copper instead of iron?
Copper reserves on Earth are very large, and elemental pures are readily available in nature. Among the shangzhou ancient copper mine sites that have been excavated, most of the copper mines are distributed in the contact zone between the igneous rocks and the Dali rocks. This contact zone is where two different geological formations come into contact.
The rocks in the contact zone are broken and relatively easy to extract. Of course, if the role of atmospheric precipitation and leaching is taken into account, the copper element on the surface is relatively concentrated in the contact zone, and the closer to the surface copper, the more enriched the copper grade. This is the ore enrichment zone.
In ancient times, when productivity was relatively low, it was easy for ancestors to find and mine copper deposits in the oxide ore enrichment belt.
Some people may say that the reserves of aluminum and iron are not small, why were they discovered and used so late?
In fact, aluminum and iron exist in nature as compounds, and it is not easy to refine into a pure body. Compared with copper, these two elements are more active, resulting in a more difficult refining process.
It can be seen that the earliest metal products used by people are closely related to the difficulty of obtaining and refining this metal. Comparing the three metals of copper, iron and aluminum, copper is the most easily obtained and relatively stable, iron is second but it is relatively difficult to refine, and aluminum is the most lively and not easy to be controlled.
The Book of Han and the Chronicle of laws records that "copper is the finest of things, not for dryness, wetness, cold and heat to change its knots, and not for wind and frost exposure to change its shape." ”
Therefore, humans were the first to use copper as a metal. Of course, the hardness of pure copper is not enough, and in order to improve the hardness, people have added tin or lead alloys. These copper alloys have been buried in the ground for a long time, and the color is blue and gray due to oxidation, so people call them bronze. The corresponding era was the Bronze Age.
Worldwide, from 4000 BC to early AD, the Bronze Age lasted about 4,000 years. This period of time is still relatively long.
Specific to the different civilizations of the world, this time is different. Around 4000 BC to 3000 BC, people in southern Iran and Mesopotamia used bronze; in 3000 BC to 2000 BC, Indians and Egyptians used bronze; in 4000 BC to 3000 BC, bronze appeared in Europe.
The use of bronze in China can be traced back to the late Longshan culture or the Longshan era, dating from about 3000 BC or a little later. However, because the copper remains found are only sporadic, to a certain extent, they do not fit the characteristics of the Bronze Age. Western scholars believe that China's Bronze Age came even later.
The timing is debatable, but one thing is certain. During the Shang and Zhou Dynasties, China's bronze smelting and casting industry developed to its peak. The Shang Zhou people used bronze mainly to make bronze ceremonial vessels. Such as the cooking utensils represented by ding, the wine vessels represented by jue, the water vessels represented by the plates, the musical instruments represented by the bells, and even the weapons represented by knives, axes, cymbals, and ge.
Many of these artifacts are practical tools, but the ancients paid attention to etiquette and gave bronze ware the meaning of etiquette. The ancients combined bronze with royal power and divine power to make a variety of ornaments, which accelerated the improvement of the level of craftsmanship. In the world, the quality of bronze in our country has a very high standard. If you take into account the excavated artifacts, time span, and geographical distribution, China's bronzes are absolutely in an unshakable strong position.
As for why bronzes were not used on a large scale later? The reasons are not complicated. Iron smelting technology has been improved and spread, and humans have been able to smelt iron and make iron tools. With the blessing of technology, and iron is harder than copper, and the raw materials for ironmaking are more abundant than copper, human beings will naturally abandon the use of copper on a large scale, and society will gradually enter the iron age.