As a diamond jewelry salesman, you are in contact with diamonds every day. Have you ever considered where diamonds come from? How are diamonds formed? Ancient Indians believed that diamonds were composed of five "elements": water, fire, gas, earth and energy. The ancient Greeks believed that diamonds were composed of four "elements": water, earth, fire, gas and so on. China Buddhist scriptures say "Hua Yan Jin Gang, this treasure comes from gold", which means to extract diamonds from gold. Polat believes that diamonds are alive, and they are descendants of gold. Even more interesting is Cervantes, Aristotle's favorite student. He thinks diamonds are divided into men and women. He once witnessed a pair of diamonds giving birth to a small diamond.
Modern science, technology and means provide new ideas and methods for exploring the formation of diamonds. Diamonds are the hardest and simplest gems in the world. It is a cubic natural crystal composed of carbon. Its composition is basically the same as our common coal, pencil lead and sugar. Carbon element crystallizes into graphite (black) at high temperature and pressure, but it crystallizes into precious diamond (white) at high temperature, extremely high pressure and reducing environment (usually anoxic environment). In order to understand the origin of diamonds, first look at the original rocks containing diamonds.
Since the discovery of diamonds in India, we have been hearing stories about people finding diamonds on rivers and beaches. This is because the original rock containing diamonds located in the upper reaches of the river is weathered and broken, and the diamonds are taken downstream with the water flow, and the heavier diamonds are buried in the gravel. What is the original stone of a diamond? 1870, diamonds were dug up in the loess of a farm in South Africa. After that, the excavation of diamonds moved from the river bed to the loess. Below the loess is a hard dark blue rock, which is the original stone of diamonds-kimberlite. What is kimberlite? Kimberlite is an alkaline ultrabasic volcanic rock, which is formed in the deep part of the earth and contains a lot of volatile components such as carbonic acid gas. This kind of rocks often contain peridotite and eclogite fragments from the deep earth, and the main mineral components are olivine, phlogopite, carbonate, pyroxene and garnet. The study shows that kimberlite magma was formed in the deep part of the earth below 150 km. Because this rock was first discovered in Kimberly, South Africa, it was named after this place name.
Another kind of original rock containing diamonds is called K-Mg lamprophyre, which is an overbased magnesian volcanic rock. It is mainly formed by leucite and volcanic glass, and may contain minerals such as pyroxene and olivine. Its typical origin is argyle, Western Australia.
Through the study of diamonds and their primary inclusion minerals from different mines in the world, scientists found that the formation conditions of diamonds are generally 4.5-6.0Gpa (equivalent to the depth of 150-200km) and 1 100- 1500 degrees Celsius. Although diamonds can be formed in various periods/stages of the earth's history in theory, most of the mines currently mined were mainly formed in two periods: 3.3 billion years ago and12-1700 million years ago. For example, some diamonds in South Africa are about 4.5 billion years old, indicating that these diamonds began to crystallize in the deep part of the earth shortly after its birth. Diamonds are the oldest gems in the world. The formation of diamonds needs a long historical process, which can be confirmed by the fact that diamonds are mainly produced in the ancient and stable mainland areas of the earth. In addition, the impact of extraterrestrial stars on the earth can produce instantaneous high temperature and high pressure, and can also form diamonds. For example, the report of the former Soviet Academy of Sciences 1988 found diamonds in meteorites, but the diamonds formed by this action have no economic value.
Rare diamonds are mainly produced in two kinds of rocks, one is peridotite and the other is eclogite, but only the former has economic significance. So far, there are two kinds of peridotite containing diamond: kimberlite (named after a place name in South Africa-kimberlite) and K-Mg lamprophyre, both of which are produced by volcanic eruption. Rocks formed deep in the earth are brought to the surface or shallow part of the earth by volcanic activities, and this magma is mostly produced in the form of rock tubes, so it is commonly known as "tube ore" (primary ore). Kimberlite or K-Mg lamprophyre containing diamonds is exposed on the surface and weathered and broken by the external forces of the earth such as wind, rain and rain. Under the scouring of water, the broken protoliths and drill bits are taken to the riverbed and even the coastal zone to multiply, forming alluvial sand deposits (or secondary deposits).
The origin and mining of diamonds
The origin and mining of diamonds
1 Which country is the best diamond produced in?
As far as rough diamonds are concerned, the best diamonds come from the impact deposits mined by De Beers in Namibia. These diamonds have traveled a distance of 1000 miles from their original place of formation to the impact seam. After this journey and the constant beating and scouring of the sea, the fragile part of the diamond gradually separated.
Which countries in the world have discovered and mined diamond deposits?
At present, more than 20 countries in the world are mining diamonds, but their constants vary greatly. In terms of value, the total amount of diamonds produced by the following countries accounts for about 95% of the world total. They are Botswana, Russia, Angola, South Africa, Namibia, Congo (Zaire) and Australia; In the next few years, Canada's diamond production will account for 10% of the world.
How to find and buy "South Africa" diamonds?
Once a diamond is polished, it is difficult to prove its origin. In fact, the evaluation of diamond quality does not depend on the origin of diamonds, but should be based on the general 4 C evaluation criteria.
Since diamonds are only made of ordinary carbon, why are they so expensive?
Diamonds were formed in the depths of the earth at the beginning of the formation of the earth billions of years ago, which is a miracle of nature. Pure carbon crystallizes under extremely high pressure to form diamonds. Such natural conditions cannot be replicated. Finding and mining diamonds is also an extremely difficult project. It costs millions of dollars to find and mine a certain number of gem-grade diamonds. Diamonds are rare, so they are extremely precious.
5 how to distinguish Russian, Israeli, Belgian and Indian cuts?
The cutting of a diamond depends on the goal of a particular cutter. Many cutting centers offer various kinds of "cutting". Today, a cutting center has no specific cutting, so even at the same time, the cutting quality is not exactly the same.
What's the difference between South African diamonds and Russian diamonds?
No two mines produce exactly the same diamonds. There are tens of thousands of kinds of diamonds produced in Russia and South Africa, including various colors and qualities. There must be differences between the diamonds in these two places. Generally speaking, a considerable part of rough diamonds produced in Russia are angular, but rough diamonds produced in South Africa are smoother. But there is no difference between the two after polishing.
7 Does "Russia" mean CZ?
Russia is a major producer of natural gemstones, but there are also some synthetic products in Russia. This makes customers confused about the meaning of the word "Russian stone". CZ refers to synthetic cubic zirconia, formerly called "Russian diamond", which is an incorrect name. CZ is not a diamond at all, but a synthetic cubic zirconia, which is clearly stipulated in the name standard of the national jewelry and jade standard.
How deep under the earth's surface can diamonds be found? Can diamonds be found in the river?
Diamonds in primary ore-Diamonds in kimberlite pipeline can reach underground 1000 meters. Diamonds in secondary mines-Diamonds in impact mines usually appear in a wide area near the surface. They are often accompanied by surface water flows, such as the banks of the Orange River, estuaries and Namibian coast in Central Africa, West Africa and South Africa, which impact the veins for 3000 kilometers.