Super Deep: Precious Diamonds Unlocking Earth's Secrets

 

 The parcel was sent in a simple cardboard box to 'S Newman & Company', a mining agency in central London, and weighed just one pound (about 500 grams).

 Although it looked like a very ordinary parcel, the truth was that it was not an ordinary parcel at all.

 It was April 1905 when the manager of a premier mine in South Africa was inspecting the underground routine when he caught a glimpse of light reflecting off a rough wall above his head. He thought it was a large piece of glass that his colleagues must have stuck there as a joke.

 He took a knife out of his pocket, and after a little digging, the knife broke. The stone was eventually extracted successfully but was later revealed to be a real diamond.

 It was a huge 3106 carat diamond. About the size of a fist. It was not only huge but also extraordinarily transparent.

 Later this diamond was named 'Clinan' which is the largest diamond ever discovered in the world. Once it was polished and combined with several other stones, it began to shine like a star in the galaxy. That is why this stone 'Clinan I' is also known as 'Great Star of Africa'.

 Almost 120 years after its discovery, this big diamond could not be forgotten. During Queen Elizabeth II's funeral, a number of Clennon-cut diamonds were placed on her coffin and were only removed when the Queen was being lowered into the royal vault for burial.

 This is because today these giant jewels are part of the royal jewels which are usually kept in the Tower of London and brought out for state events. Clannon I is now enshrined in the scepter of the British monarch, while Clannon II, carved from it, is enshrined in the royal crown.

 However, this diamond in the rough made its place in history much later before it needed to be sold, for which London was chosen. But here comes the problem, how do you move such a precious stone to a place 7,926 miles (12,755 km) away while protecting it from thieves and looters?

Finally, the gem was sent from Johannesburg by ordinary registered mail, which at the time cost just three shillings or about 75 US cents, which is about £11.79 or $13.79 today.

 Meanwhile, a replica of the diamond was on its way to London by boat, guarded by a captain and police detectives. Amazingly both real and imitation diamonds were delivered to the destination. After failing to sell for many years, the original version of the diamond was purchased by the Transvaal government for £150,000 (£20 million or £22.5 million today) and gifted to King Edward VII.

 Although these diamonds are known throughout the world for their size and clarity, these characteristics did not come about by accident. Culinan was a diamond in the rough, it is placed in a special category and has many qualities besides beauty.

 These diamonds, in all their beauty, come from the depths of the earth. Fascinating geological anomalies that are merely ornaments. These strange rocks are otherworldly capsules that come from a mysterious region of immense pressure, swirling green rock, and mysterious minerals far below Earth's surface.

 Scientists from all over the world have been studying this subterranean area for decades to uncover its secrets. And interestingly, the diamonds we value the most have the most extraordinary stories behind them.

 In fact, giant rocks like Cullen are changing our view of our planet's interior.

 A rare opportunity

 Sitting in front of a microscope at the Gemological Institute of America (GIA) in 2020, Evan Smith carefully slipped rubber gloves over his fingers, and peered down through the instrument. Beneath it was a diamond the size of a walnut, worth about the size of a small country. This 124 carat diamond had a wonderful sparkle.

 Smith had already cleared several types of security to reach this point. After an iris scan and identity check, followed by locked doors, secured elevators and mysterious restricted corridors, they reached the room where they were working. While they are working, vigilant security guards are watching the live video from the video cameras in the room.

 Smith, a senior research scientist at the GIA, was examining the region of diamond from our planet's interior to see how it forms and the chemical changes that could reveal how and under what conditions the crystal formed. .

 But working on high value diamonds is a difficult process. It is usually impossible for researchers to access the largest samples. These diamonds sometimes travel the world to meet potential customers, but unfortunately never meet the scientist.

 "It's hard to get any diamond samples, and most of the diamonds she works with would probably have been thrown away," says Maya Kopelova, a professor of mineralogy at the University of British Columbia.

"Researchers have to have good relationships with companies, but they will never give you valuable samples," she says. They will never give us diamonds that are six millimeters (0.2 inches) in size or larger.

 However, accessing these diamonds is a difficult and expensive process. First, Maya Kopelova has to visit the high-security facilities where the diamonds are sorted and identify the specimens she wants to research.

 After approval, comes the paperwork. All diamonds must be transported with Kimberley Process Certificates, which prove their origin and help prevent conflict or blood diamonds from entering the market.

 However, Smith's situation is different. At GIA, they have access to one of the largest collections of diamonds on earth, with millions of gems sent to be valued so they can be insured or sold. "If you want to see something rare and unusual, this is the best place because diamonds come in all the time," says Smith.

 Smith did the same a few years ago. Together with an international team of scientists, he procured 53 of the largest, clearest and most expensive diamonds, some from the Cullen mine, and took them to his laboratory for microscopic examination.

 What Smith saw was amazing. Three-quarters of the clipper diamonds were housed in metal casings that were rust-free. This is usually not the case. While 15 found ruby, which is found only in the upper layer of the Earth's molten core.

 From this it was not difficult to deduce that these diamonds were formed somewhere between 224 and 466 miles underground. This indicates that the metal casings contained in them were free from rust due to the absence of oxygen at this location. And also that despite the extreme pressure, the rubies were also found to be intact. Common diamonds are formed at a depth of 93 to 124 miles.

 According to Smith, (common) diamonds are geologically strange minerals. We spend millions every year to extract them, more than the budget allocated for any project.

 Common diamonds are also quite different from other gemstones. No other object has come to the surface from this deep (373 miles down) in the Earth. The magma that reaches the surface also comes from 249 miles down, mainly liquid rock.

 All diamonds are at least 990 million years old, except for lab-grown diamonds. This is the time when life was emerging in its earliest form. While some diamonds started to form 3.2 billion years ago. At that time the earth was like a great raging sea.

 Once a diamond is formed, it has to face many unexpected conditions before it reaches the surface. The superheated interior of the Earth propels it upward. This process also takes millions of years.

In the 1980s, geologists noticed that some diamonds had different textures than others. In some, minerals were found that appeared to have formed under pressure greater than normal. "We started to wonder if some diamonds had grown deeper than others," says Smith.

 He noticed that some of them had a high nitrogen content, which had an effect on their crystal structure and a slight yellow or brown color appeared in it. These were type two diamonds which are very rare.

 Scientists eventually discovered the secret, and that was that they were formed at great depth. And that's why he was called 'Super Deep'. He also identified some mines where such diamonds, including Culinan, can be found. These mines are mostly in South Africa.

 But the diamonds found at depth in the last several decades were small in size and of low value. "We never gave them much importance," says Smith about them.

 But in 2020, they saw a mineral that was found only six years ago, that too in the 4.5 billion-year-old meteorite that hit the Earth in 1879. It was believed that this space rock was broken by a asteroid and fell to Earth. And the cause of its rupture was the ever-increasing pressure. The exact same pressure as is found at the center of the Earth.

 The space rock broke up into more pieces as it fell to Earth and the pieces were scattered across Queensland, Australia, many of which were collected by a geologist's widow and donated to the British Museum in London. .

 In 2014, scientists found the mineral Bridgmanite on one of these fragments. Although this mineral is abundant on Earth, it only exists under extreme pressure. This pressure is found only in the layer above the center of the earth. Such minerals break down when they reach the surface.

 Surprisingly, the 124-carat diamond that Smith studied contained this mineral, albeit in a shattered state. Even though the diamond is inside, it does not withstand the difficulties of traveling to the surface.

Ancient carbon

 According to Smith, the secret to the extraordinary properties of the world's largest and most valuable diamonds lies in the stages of their formation.

 Even the origins of ordinary diamonds are somewhat mysterious, but it is believed that they began life in the form of a fluid. More likely, it is seawater that gets trapped deep underground and then changes in temperature and pressure cause this mineral-rich water to expel dissolved carbon. This carbon crystallizes into diamond due to the great pressure in the earth's inner layer.

 But super-deep diamonds like Cullen's are a different matter. They start with carbon in the liquid metal instead of starting in water.

 "It is like molten iron mixed with sulfur and carbon," says Smith. So it's a completely different kind of fluid, but it also contains carbon. This liquid metal is affected by chemical or temperature changes, causing the carbon within it to turn into vapor.

 Since the amount of nitrogen in it is low from the beginning, it remains low even after the diamond is formed. And such a diamond is more transparent.

 In short, clipper diamonds are not only common in type and size, but their basic structure is different from other diamonds. In fact, their unparalleled size and transparency is a direct result of their process. Their discovery has revealed some of the best secrets of the earth

"I think the most important thing about these [super-deep diamonds] is the subduction zone, the process where plates or segments of the Earth's crust slide down or sideways and meet another plate," Smith says. are.'

 The earth consists of seven tectonic plates, which are floating and their mutual friction creates earthquakes on the earth.

 Super-deep diamonds can provide important information about the movement of these plates. "These diamonds tell us that this process is actually happening," says Smith.

 Apart from this, these diamonds reveal the process going on in the deepest part of the earth and also that carbon is present there, otherwise diamonds would not have been formed. But an extremely rare super-deep diamond discovered in Brazil in 2021 also hints that entire oceans may exist in the Earth's core.

 Inside this diamond is a flint box of the blue mineral ringwoodite. It is a form of olivine that forms due to extreme pressure. 2.5% water is found in such compositions.

 Scientists have long believed that most of the water on Earth's surface, whether it's in rivers, ice sheets, or lakes and oceans, is all in the submantle (the space between the Earth's core and outer layer). 

 part that is 18 hundred miles thick) came from There is no definitive word on where this water is located in the mantle, but ringwoodite suggests that it would be where super-deep diamonds are found.

 The amount of knowledge that is being gained about these super deep diamonds shows that their value must be determined not only financially, but also that without them, we would not know much about the Earth. We would have missed the information that we got through them.

 "Sure, when you're putting something under a microscope and examining it, there's an element of wonder, but when you're subconsciously aware that what you're holding is If the price is in the millions of dollars, this feeling increases even more.

 These moments happened to me too. And I thought it would be great if I could break it down and analyze it in detail. But it is obvious that this is not possible because it is such a precious thing that has remained.