What's so special about gold compared with other metals?
Au？ This is the chemical symbol of gold. There should be few people who don't know, but do you know the origin of this name? Speaking of it, I have to admire the romance of the naming person, because Au originated from a story in Roman mythology, and the protagonist of the story is Aurora, the goddess of dawn. Shining dawn? Meaning. The gold in costume dramas is generally based on? Two? As a unit of measurement, but internationally? Oz? As a measure of gold, when we go to the store to buy jewelry, do we use? g？ To describe weight.
When everyone went to school, the periodic table of elements was posted in chemistry textbooks. I was the kind of person who couldn't even remember this table at that time, but gold was a special case. I believe that few people don't know the value of gold. The essence of gold is actually pure gold. Anyone who has worn gold ornaments should feel particularly soft, and ordinary people can change its established shape with a little effort. Gold is a rare metal, but it is not a very limited metal, and it is also one of the indispensable and important materials in some science and technology industries.
As we all know, gold has strong ductility and soft texture. Only 65,438+0 ounces of gold can be stretched to a length of 50 miles, which is the strongest pulling force among known metals. The ductility of gold is particularly excellent, which is why the ancients like to make gold into a pickaxe shape and then use it as a decoration for important building surfaces. The physical properties of gold are special in color expression. When melting gold, the steam emitted will be unexpected yellow-green, a thin piece of gold will transmit green light, and the gold powder will appear brown after melting.
The so-called real gold is not afraid of fire. In fact, it is said that gold has high chemical stability and is not easy to react with substances under normal environment. Therefore, pure gold will not change color obviously and has strong corrosion resistance. For example, when the temperature reaches 1500 degrees, silver will be oxidized to produce silver oxide at high temperature, but even if the temperature rises to 3000 degrees, gold will not react with oxygen.
How much gold is there on the earth? Why is gold recognized by various world civilizations?
Things are rare, and the total amount of gold on the earth is relatively small. If it is in the crust, the average content of gold is about 0.0011ppm (1.1), while the content of gold in seawater is only 0.0001PP. The reason why gold mining is not as difficult as expected is mainly because long-term geological changes and crustal movement have enriched long-term gold elements, thus forming the so-called gold deposit. Indian scientists once unearthed a gold nugget weighing 2.5 tons.
In nature, pure gold is hard to find, because there are also iron, silver and copper in general gold-bearing substances. When the proportion of silver in natural gold reaches or even exceeds 15%, it is often called silver-gold mine. Of course, there are also so-called gold mines, palladium mines and copper-gold mines. At the same time, because gold itself has? Sulfur affinity? Because of this property, gold often appears with common sulfides, such as galena and pyrite.
The American gold market did not develop as early as many people thought. The gold markets in Chicago and new york might not have developed until the mid-1970s, but for the serious depreciation of the US dollar after 1977. This change not only accelerated the development of gold futures, but also made many Americans get a good return on investment. If we want to say which is the oldest gold market, we have to mention the London market, because its history can be traced back to more than 300 years ago.
Many years ago, whether in ancient China or other countries in the world, wars, big or small, would occur at different times. Those relatively developed countries or regions will spread the idea that gold has monetary property and human beings themselves have strong inheritance property. Therefore, we will find that even though the society has developed much more advanced than in the past, some basic facts we have recognized have not changed. For example, gold is a stable currency form and can also be used to make various exquisite ornaments.