The ancients had a passionate imagination about diamonds. They believe that the extraordinary nature of diamonds is the most perfect representative of all natural creations. It is unbelievable that a crystal stone has such amazing hardness and durability, and its ability to flash psychedelic luster is particularly fascinating. In the world, many ethnic groups regard it as their own god, and are crowned with the extremely glorious title of "King of Gems"!
What is the dignity of diamonds? First, let's look at the chemical composition of diamonds and their origins. This issue has been debated for a long time in the scientific community. Some famous scientists in history have almost speculated on the puzzling chemical composition of diamonds. But I have never found the exact answer. So there are many speculations about the chemical composition of diamonds.
The great ancient Greek philosopher Pedocles said that diamonds are composed of four elements: earth, air, water and fire. According to Indian scientists, it consists of five elements, namely, earth, water, sky, air and energy. 1704, Newton made a systematic study on it and pointed out the flammability of diamond. Lomonosov even predicted that the reason why diamonds are particularly hard is mainly because "it is composed of closely connected points". 1772, French chemist Rabago heated a diamond to make it burn, and found that the gas produced during burning was carbon dioxide! Therefore, Rabago pointed out the relationship between diamond and carbon. This conclusion is incredible, so noble diamonds are closely related to "low carbon".
It was not until 1796 that British chemist Knight came to the conclusion that diamonds were pure. As for where diamonds come from, there is great controversy in the scientific community. At first, most people thought that diamond was an underground ore. Because most of the early diamonds were mined from the sand. 1870, the world's first primary diamond deposit was discovered in northern Cape Province, which was named after Lord Kimberly, then British colonial minister. This is what became Kimberly City. Later, geologists discovered in the mining area that the parent rock of diamond is a kind of rock whose mineral composition and properties are very different from ordinary rocks. So, in 1887, the Englishman Louis first called diamonds kimberlite.
Later, some minerals similar to kimberlite were discovered all over the world. Because these rocks are similar to kimberlite in nature and mineral composition, kimberlite is recognized as the only rock-forming mother ore of primary diamond deposits. This is an alkaline ultrabasic rock without feldspar in the matrix, which is mainly composed of olivine and has many breccias or porphyritic structures. Therefore, diamond is also called breccia mica peridotite, and the rock mass usually exists in the form of leaky pipes (also called rock pipes or volcanic neck) or dikes.
According to the high-pressure minerals contained in kimberlite, the researchers speculated that kimberlite magma was formed in the upper mantle and migrated upward along the cracks in the crust under high pressure. Because it is filled with high-pressure gas (water and carbon dioxide, etc.). ), when it rises and the pressure drops sharply, its volume expands rapidly, leading to underground volcanic eruption. After the eruption, volcanic neck was filled with magmatic cemented detrital materials, forming kimberlite cones. It is said that diamonds are formed by kimberlite magma taking away inclusions in adjacent carbonaceous rocks. Others believe that diamonds are brought from the depths of the earth's crust by kimberlite and another eclogite. However, most people are now convinced that diamonds come from the sharp rise and explosion of some free carbon in kimberlite itself. During the whole magmatic activity, that is, crystallization is formed under the conditions of high temperature and high pressure. According to the above conditions, people have used extremely high temperature and pressure to produce artificial diamonds in batches.
Scientists in the former Soviet Union have proved by isotope analysis that diamonds can be produced not only in the mantle below 150 km, but also in the crust below 10 km. As long as the magma passes through the rock tube in the upper crust, narrow pores will appear in the channel. Due to this necking phenomenon, the pressure will suddenly increase from 20000 atmospheres to 654.38+00000 atmospheres. It is in this case that magma turned into diamonds.
From the late 1970s to the early 1980s, when American scientists measured the gas-liquid inclusions of Arkansas diamonds, they found that they contained hydrocarbons similar to petroleum (that is, organic compounds composed of carbon and hydrogen), such as methane, ethylene, methanol and ethanol. The average oil content per gram of diamond is about 3.3× 10-5g. Therefore, they believe that the formation of diamonds is related to hydrocarbon sources deep in the earth.
198 1 year, at the international gem conference organized by the Japanese team, Dr. Sol further elaborated the internal relationship between them. He speculated that there are abundant hydrocarbon sources in the earth, and hydrocarbon gas is easy to be preserved in ultrabasic magma. When Kimberly magma overflows upward, volatile hydrocarbon gas diffuses to the surface, while residual carbon shrinks in Kimberly magma and crystallizes to form diamond due to the rapid changes of pressure and temperature. However, in 1988, people made another unexpected discovery, which further doubted the above viewpoint. This discovery is the first time that Russian scholars Yerov Bav and Lachin have found light gray diamond particles in stone meteorites. Soon, diamonds were also found in stone meteorites. Why are there diamonds in meteorites? This issue has always been controversial. At first, it was thought that these diamonds were crystallized because of the high temperature and high pressure caused by the friction between carbon contained in meteorites and the atmosphere and the impact with the ground.
In recent years, in the National Museum of Natural History, scientists have obtained an iron meteorite from the ice sheet on the Alan Plateau in the Antarctic continent, and a diamond crystal inclusion has also been found in its slice. They speculated that this meteorite was originally a fragment of an asteroid, and the diamond crystals contained in it were formed before it fell and when two asteroids in the asteroid belt collided millions of years ago. The reason why this kind of iron meteorite has diamond inclusions is that asteroids collide at a very high speed (about tens of thousands of kilometers per hour), which produces great impact pressure and then converts natural carbon into diamond.
Lewis and Walter of the University of Chicago in the United States began to study four meteorites that fell in Mexico and other places in 1969. They unexpectedly found countless very fine diamond powders, which also contained a small amount of xenon with a special proportion of isotopes. After determination, it shows that they are older than the solar system, and they were all produced 4.5 billion years ago. This conclusion shows that the formation of diamonds and the collision or fall of meteorites have nothing to do with the earth.
To sum up, these scientists have overturned the traditional view that high temperature and high pressure in the earth can promote the production of diamonds. Therefore, they boldly suggested that diamonds in nature were probably formed billions of years ago due to the destruction of a red giant-a dying "star".
Scientists infer that at that stage, rich hydrogen and high temperature are particularly conducive to the concentration of carbon gas and the formation of crystalline diamonds. At the same time, the red giant will reinforce a large amount of gas, which will expand and cool, so that substances such as carbon will condense and crystallize. Thousands of years later, when the red giant finally explodes into a supernova, it will eject high-speed ions, including charged xenon atoms, which will catch up with the escaped diamond particles and be buried in them. It can be inferred that the number of diamonds formed in the universe may be amazing.
In the universe, because diamonds participate in the evolution of the solar system, they can be found on the earth and meteorites. Therefore, people will ask this question, do beautiful diamonds come from the sky or from the ground? This is an elusive mystery.