钻石的鉴赏-英国Essay范文－r51due

英国essay论文精选范文：“钻石的鉴赏”，这篇论文讨论了钻石。世界上近200种宝石中，钻石非但因其坚硬和无与伦比的美丽独占鳌头，而且在自然界中也最为稀少，因此被誉为“宝石之王”。衡量一颗钻石品质的标准主要有四个维度，即重量、净度、色泽和切工，也就是通常所说的“4C标准”。

Nearly 200 kinds of gems in the world, diamonds are not only due to their hardness and unparalleled beauty come out on top, but most rare in nature, it was hailed as the "King of gems". Despite thousands of years of history of human civilization, but was found and an initial understanding of diamonds only hundreds of years really uncover the mystery of diamond internal time is shorter.

Diamond is the world's most ancient gemstone, diamond, after pondering it get that finished and diamond is a natural substance, is the original stone diamond. The youngest diamond has more than 35 million years. Diamond was the hardest stones on Earth. Diamond formation in the 150~200 kilometers below the surface of the vast majority of the world's regions, why is that? As we all know, deeper into the higher pressure and temperature inside the Earth. For example 30-kilometer near deep temperatures hundreds of degrees Celsius, more than 10,000 atmospheres pressure if deep 100-kilometer, into a temperature 1000 ℃, 30,000 atmosphere. It is often said that toughened, diamond formation than the harsh harsh far more than a thousandfold! As long as millions of years ago, early Earth was born, 150~200 km of the mantle from the surface, there are up to 1000 ° c and 1300 ° c high temperature, about 45,000 to 60,000 atmospheres. Under the environment of high temperature, high pressure and oxygen, carbon atoms crystallize becoming precious diamonds.

Another major reason why diamonds are extremely rare, extremely rare carbon deep in the Earth. We know that most of the chemical elements that make up Earth is oxygen, followed by Silicon, aluminum and iron. The 4 elements 87% per cent of the Earth's total mass; 3 elements combined with calcium, sodium, potassium, total 96%. The remaining 4% are all other elements, including the carbon. Composition of the Earth's elements, more massive elements gathered in the center of the Earth. The element carbon is lighter, concentrated near the surface, which basically does not have carbon deep in the Earth. Since the birth of the Earth 4.6 billion years ago, carbon within an extremely rare, so not many diamond raw material within the Earth. Diamond deep in the Earth where the raw materials come from? Through isotopic analysis of forming the diamond material, at least in part, is a legacy of organic carbon. This means that, in the hundreds of millions of billions of years of sediment to the bottom before plankton) remains, with the movement of tectonic plates, them from the sediment were taken to the Interior of the Earth, where it is possible to form a diamond. This condition is very rare, so limited diamond is extremely rare earth formed billions of years.

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Diamond deep in the Earth for millions of years, have been waiting for the opportunity to come into the world. Violent volcanic eruptions, make it all possible. The kimberlite pipes of volcanic eruptions has developed a unique, magma, as well as a lift, carrying the 150-kilometer deep in diamond and other rocks and minerals, up through the Earth's mantle, breaking the crust, come to the surface.

Concentrated in underground 150-kilometer deep formed of diamond, to became human can utilization of diamond, it also must overcome series adverse factors: If magma cycle will diamond with to deeper of parts, diamond will into free of carbon Atomic; if Dang diamond and volcano magma with rose Shi slow cooling, diamond will into graphite; if diamond was magma from Shang mantle dramatic eruption to surface, fast cooling Shi, it is may real was human using. Even so, not all diamonds are to become a jewelry diamonds. Experienced mining of the ore body, still need to go through multiple processing selection before they can obtain rough diamond. Only 20% of rough diamonds for jewelry purposes around the drill blank, and most can only be used for cutting, grinding and polishing and other industrial uses. It has been roughly estimated, to get a 1-Carat Diamond, at least 250 tons of ore mining, mining rate is fairly low; if you want to pick out diamonds from the polished diamond, that ratio is the great disparity of the two.

Looking for diamond deposits, not as exciting as the legendary, careful not to fall down you will find a diamond deposit. Find diamond deposits tend to take decades, even centuries of effort and labor is expensive. Such as the former Soviet Union Siberia primary gold

Search diamond deposits, since 1913, after 18 years of hard work, can be found in Botswana "Euler" original deposit, at a cost of $32 million, after 12 years of struggle to dig out; in recent years, the Canada primary diamond deposit found in the Northwest, are going through hard efforts of several generations of geologists, found only at a cost of at least hundreds of millions of dollars.

Mining of diamond deposits, can be said to be a huge, but care and solicitude. Mining process, the need to fully exploit the ore containing diamonds, but also cautious to ensure that ore, diamond stone particles intact. Whether open pit mining, underground mining, is a momentum and a vast array of engineering, human and material inputs is unimaginable.

Diamond processing complex, the amount of work. Carefully mined ore after crushing and sorting is not just like any other metal deposits, can be put into large quantities of smelting, but rough diamonds-by-grain meticulously analyzed to confirm cutting programme to ensure its weight, clarity and style. This often requires physical and optical properties of the diamond itself have a full understanding, who has considerable experience. General steps are: design lines, splitting drilling, sawing drilling, drilling, drilling, cleaning grinding and classification. And that many small programs are also included in each step. Each small step is required superb technology and rich experience. Take for instance the kulinan of the world's largest diamond, the original stone weighed 3106 carats, 3 experienced, skilled craftsmen, working 14 hours a day, total took 8 months, will split it into 4 large diamonds and 101 small diamonds. Some of the world famous diamond processing, often only designed to spend months, even his 1-2 time.

According to Belgium Antwerp Diamond High Council said, to 250 tons of rock, sand and gravel processing may get a 1-Carat Diamond embryos, embryo 1 Carat diamonds by cut, can only hold weight of 40%~50%. 1 Carat equals 0.2 grams, 250 ton is equal to 250 million. In addition, diamonds mined most of poor quality, can only be used as an industrial abrasive or drill bit. Often used as a gemstone diamonds diamond ore could not be one-seventh. Real diamond to reach our consumers, even rarer. According to some preliminary statistics, a diamond from its mining, sorting, processing, grading, marketing, and finally sold to buyers, some involving more than 2 million people, a diamond ring is a natural God and more than 2 million people crystallization, the precious diamond is among them.

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