Diamond processing: the preparation process from rough to millions of diamonds

Diamond processing

One of the 4C standards is cut, which is for brilliant cut diamonds. When other factors are the same, the diamond value of the brilliant cut process is regarded as the highest. So how many cutting methods are there for diamonds? Here is a brief introduction to the methods

Please refer to the 4C standard of diamonds as follows:

CROWN: The part above the diamond is called the crown, including 1 table (TABLE), 8 star faces (STAR ​​FACET), 8 kite faces (BEZEL FACET) and 16 upper waist faces (UPPER GIRDLE FACET) ), a total of 33 faceted waist circumference (GIRDLE): the widest part of the diamond is also the junction of the crown above the divided diamond and the lower pavilion. The waist circumference is the place where the diamond is fixed when the jewel is set. Pavilion (PAVILION) The part below the diamond is called the pavilion, which is the part from below the waist to the tip of the diamond. Including 16 waist faces (LOWER GIRDLE FACET), 8 pavilion facets (PAVILION FACET) and 1 bottom cusp face (CULET), a total of 25 facets; because diamonds do not have a cusp face, so there is no point The diamond pavilion on the bottom has only 24 facets, and the total number of facets is 57. However, with the development of cutting technology, more and more surfaces can be cut, and it is generally believed that the more cutting surfaces, the more shining. I have seen 74 facets, 88 facets and the most cuts of 200 facets, but they are very rare. For some rare cutting methods, the jewelry will usually show the corresponding certificate.

F color octahedron

The following common cutting methods for brilliant cutting

For diamonds of the same size and clarity, in addition to highlighting their classic processing techniques with inlay methods, brands have gradually used unique cutting methods to develop their own cutting skills. Novel cutting methods can be patented. For example, the picture below is the cutting method called LUCIDA that TIFFANY obtained a patent in 1999. TIFFANY and CARTIER have introduced their own patented cutting methods. However, it is hard to say how novel it is. Failure to observe is the integration of some of the above cutting methods, and the requirements for the cutting machine are very high. But there is only one purpose, the pursuit of different brilliance, the degree of brilliance of diamonds presented by different cutting methods are different. Whether to choose the brighter the better, such as the bright type, or the more restrained one, such as the square type, it depends on the individual. orientation. However, from a price perspective, the higher the demand, the more expensive it is. The 200-hedron is much more expensive than the 57-hedron. In the value of diamonds, the pursuit of processing technology depends on personal positioning.

Polyhedral crystal


The first diamond to appear on is a rough natural octahedral shape. Since about the 14th century, people have processed diamonds to a certain extent

Diamond-level cutting process

Later inlaying, early cutting craftsmen managed to sharpen the diamonds; table cutting appeared in the fifteenth century, and rose-cutting began to appear in the sixteenth century, and this cutting style continued until the nineteenth century. The emergence of brilliant cut is a major advancement in diamond cut, which gives diamonds a better brilliance and fire. In 1914, the diamond cutter Marcel Tolkowsky published his cutting ratio according to the refractive index and dispersion rate of the diamond, which was welcomed by the general public. Although today's brilliant cut has been improved, most of it is still based on support. Based on the ratio calculated by Coffs. However, diamond cutting is a product of the combination of art and technology, requiring long-term accumulation of experience and talent training, so diamond cutting is mainly concentrated in those traditional cutting centers. Currently, there are four main cutting centers in the world. India, New York, Antwerp, Israel. In addition, Thailand, China, and Russia are also developing into major diamond processing and cutting centers. Every dazzling diamond needs careful cutting and processing to make it release its due luster and brilliance. This is also the perfect combination of man and nature. However, the usual terms in the industry "Russian workers", "Belgian workers" and "Indian workers" have no direct source relationship with the above cutting centers. It is processed, but it implies that the cut of this diamond is perfect. (The relevant content will be introduced in the 4C evaluation section).

pro 1

A rough diamond does not look conspicuous. It must be carefully cut and processed to become the sparkling diamond that we are used to seeing. Therefore, the workmanship of diamonds directly affects the value of diamonds, as detailed later. The most ideal cutting effect is of course to maintain the maximum weight of the diamond, minimize blemishes, and fully demonstrate the beauty of the diamond in order to make the diamond. The general cutting process includes the following steps:


This is the first step in diamond cutting. The rough is inspected and the diamond surface is marked. The people who do this work have rich experience and proficient in processing technology. The ultimate goal is to produce the largest, cleanest, and most perfect diamond to reflect the value of diamonds as high as possible. The liner must pay attention to two points: that is, to keep the maximum weight as much as possible, but also to minimize the inclusions. The liner uses a magnifying glass to study the structure of the rough diamond. In the case of large diamonds, this work may take several months, while for ordinary diamonds, it takes several minutes. However, no matter how small the rough diamond is, every diamond must undergo a detailed inspection to make a correct judgment.

The liner uses ink to mark on the diamond blank, indicating that the diamond blank is to be divided along this line. It is usually possible to draw a line along the diamond's natural grain direction as much as possible.

Splitting and sawing

Splitting: The splitter puts the diamond blank with the drawn line on the frame, then cuts a dent along the dividing line with another diamond, and then puts the square knife on the dent, and beats it by hand. When the knife is struck with appropriate force, the diamond will be split into two or more pieces along the grain direction.

Sawing: Most diamonds are not suitable for splitting. At this time, they need to be cut with a saw. Since only diamonds can cut diamonds, the saw blade is a phosphor bronze disc coated with diamond powder and lubricant on the edge. The diamond is fixed on the top and the saw disk is used to cut the diamond. The introduction of modern laser technology into diamond cutting greatly improves the processing efficiency of diamond blanks.

Forming: The sawn or split diamonds are then sent to the rounding department for rounding and forming, that is, according to the design requirements, the diamonds are made into common cut flower shapes such as round, heart, oval, pointed, and other shapes, or other shapes. Special shape. Since diamonds are the hardest natural substance recognized by mankind so far, only diamonds can polish diamonds, and the hardness of diamonds is slightly different in all directions. Therefore, you must rely on experience to grasp the basic shapes of diamonds: trigonal, octahedron, dodecahedron and crystal characteristics. The general method is to turn the diamond blank on a high-speed rotating lathe, and then use the diamond on the other arm to round the rotating diamond blank.

Starting polishing

On a cast iron disc coated with diamond powder and lubricating oil, the car grinds out all the petals (facets), so that the diamond emits a seductive brilliance. The grinding process is usually to make 8 large faces on the bottom layer first, and then make 16 facets. Add a sharp bottom, a total of 25 facets, correct the wrong, and extend the triangle facets, kite face and waist facets, a total of 33 facets, such a round diamond has a total of 58 facets, If there is no culet facet, there are 57 facets in total.

Not every diamond blank has to go through all the above processes. This depends on the characteristics of the diamond blank and what it wants to achieve.

Diamond polishing process

Depending on the goal, for example, the aforementioned "flat" diamond blank may not need the process of splitting, and for processing diamonds, the process of "rounding" may not be necessary. However, for any rough diamond, there are two processes that are indispensable, which are "scribing", "petaling, polishing". The position and angle of the petals produced by a finely cut diamond are accurately calculated, so that the diamond emits the greatest brilliance. It can be seen that cutting the hardest gemstone in the world-diamond, not only requires advanced equipment, but also requires the cutter's rich experience, high sense of responsibility and full attention to release all of the diamond. A diamond in the jewelry counter may have traveled through many countries. It has been processed, inlaid, and made by several people before it becomes a diamond jewelry. With the advancement of science and technology, the introduction of laser technology and electronic computer technology can make the design and cutting of drill blanks more accurate.

Standard test

Although round diamonds are the most common cutting method on the market, sometimes it feels a bit monotonous, but round diamonds are the most brilliant shape of all cuts, so round diamonds are the best! So, do you know how many faces a standard round diamond has, which faces are there, and what kind of cut is the best?

Standard Round Brilliant

The most common forms on the market include: 1 table top, 8 kite facets, 8 star facets, 16 waist upper facets, 16 waist lower facets, 8 main facets at the bottom, and a pointed base with or without , A total of 57 or 58 facets. The following picture clearly shows the specific positions of the above several faces of the diamond: Well, we can see this picture very clearly. Some people always say why some are 57 and some are 58 faces? In fact, it is very simple. It lies in the sharpest point of the diamond-the Culet culet. Generally speaking, diamonds smaller than 5 carats have no culet, so the Culet culet on the certificate is None or Very small, etc. That is, the bottom tip is not or is so small that it can be ignored, that is, 57 faces. In order to protect the diamond from damage, large-grained diamonds generally have a flattened culet, so there is an extra side, that is, 58 sides. Many people often think that the more facets a diamond is, the better. In fact, this is not the case. There are many cuts of diamonds, especially special-shaped diamonds, which can extend many facets. Not all facets are better with more facets. As a round diamond, the standard brilliant cut (57-58 faces) is also classical, which is a very classic and perfect cutting method. The value of the above 57 faces directly affects the quality of the diamond. Therefore, we call the diamond cut with the most standard ratio within a certain value range as "perfect cut", that is, "IDEAL CUT". Diamonds are under such numerical standards. Can emit the most perfect light! Therefore, such diamonds are the most worthy of collection and investment and the most expensive under the same circumstances as other 3Cs.

Cutting street

This inconspicuous old industrial district has a 400-year-old super diamond cutting center with annual sales of more than 20 billion U.S. dollars. In Nieuwe Uilenburger, a featureless, indescribable old and new Amsterdam neighborhood, the car stopped just like that. "Here." The driver said simply. He added another sentence when I got off the car: "I hope you brought enough money. The person who was confused by marijuana during the tour lacked reaction to this cold humor, and walked to a low-key but well-guarded one. The doorway. The clerk on the other side of the glass door nodded at me, got up and pressed a series of numbers estimated to be a password on a small control panel. The glass door outside opened, and I stepped in and met the first Two glass doors. At this time, the outside door closed again. The staff member pressed a set of numbers or letters on the control panel, and the second door opened. I walked into the real room and subconsciously breathed a sigh of relief. "Welcome to Gassan Diamonds, we will have someone to accompany you to visit our diamond processing workshop later. "Another employee walked down the dark aisle and said. Five minutes later, I finally reached a certain level inside the diamond center (the stack of stairs and the marijuana smoke I inhaled made me dizzy), and glanced at it. In the past, it was a small room separated by frosted glass. The staff who accompanied me led me into one of them. A lady in black with considerable "tonnage" was already seated in the room, like a 3 carat diamond. Majesty. "I will briefly explain to you the classification and grade of diamonds. "The big-tonnage lady first took me to review the 4C standards of diamonds, namely carat, color, cut and clarity. Any combination of these four standards will greatly affect the value of a diamond." For example, a white diamond. (Wesselton) will be several levels higher than the price of a light yellow diamond (Cape), but if its clarity is only the worst grade of PIQUE 3, the price will drop significantly. A high-quality Wesselton white diamond ( Top Wesselton), a perfect 1 carat diamond, the price will be the same size, clarity (Crystal) geometric level, because there is a probability problem-you can find a diamond with perfect 4C, chance not much. "

Diamond old mold

The unquestionable authority of pricing is an important reason why the 400-year-old Gassan diamond has become Amsterdam's annual reception of as many as 350,000 tourists. Gassan, along with other large diamond processing and dealers, has enabled Amsterdam to be the largest and most important in the diamond trading industry with annual sales of at least 20 billion U.S. dollars. "On diamond trading, the only one that can match us is Antwerp. We are the sister center of diamond trading," said the big-tonnage lady. This is all thanks to the Jews who brought diamond cutting technology to Amsterdam when it was destroyed in Antwerp in the 16th century. You should have guessed by now that the predecessor of Gassan Diamonds, BOASBROTHERS, was founded by the Jewish family, who built the company into the largest diamond cutting center in Europe in the 19th century. Even during World War II, due to the wealth of diamond cutting and subsequent exchanges, the Nazis had tolerated Jewish control of the industry for most of the time. Today, Gassan is still in the hands of the grandson of the founder's family.

Until now, it is cutting technology that makes Amsterdam invincible in the global diamond industry chain. Walking into Gassan’s diamond processing workshop, it’s not difficult to see that the diamond cutting techniques that have been used since ancient times are still influencing today. There are no high-tech machines with buttons everywhere, no computer screens, and some are magnifying glasses and look very heavy. Tool. You might even think that the lighting here is a bit inadequate, but those cutting technicians who carefully examine their expensive works with a magnifying glass don't seem to take it seriously. Perhaps what came to mind at this time was Max Bauer’s description of the city in 1896: a huge industry employing up to 12,000 people (only cutting technicians), cutting diamonds from around the world abruptly from India. The throne of the capital has been taken over, and the city has as many as 70 advanced diamond cutting centers that use steam as the power of abrasive tools.

Use cutting standards to control pricing power

What is the significance of maintaining the commanding heights of cutting technology now? Remember in 2009, the world's two largest cut diamond trading companies, EDT and De Beers, successively launched two diamond certification standards, "Blue Flame" and "Eternal Mark", which applied brand-new cutting technologies? "The upgrading of cutting technology, for non-technical products such as diamonds, the most important significance is the price change." An insider from the diamond brand Tesiro under EDT told me. Of course, this price change is going upward. However, EDT and De Beers are unwilling to comment on whether such price increases are supported by costs. "When you sell all the old standard diamonds, or no longer sell the old standard diamonds, then the market can only accept the price of a new generation of diamonds, and the new cutting standard is the perfect reason De Beers needs." The person said. This may explain why Amsterdam, which has no advantage in the diamond industry chain, can stand up in Europe and even the world. The United Kingdom, South Africa, and Canada share the diamond ore under the banner, while the Russians hold the potential. In the diamond mine with the highest output, Indians and Chinese are increasingly becoming the largest buyers of diamonds, while Jews do not even need Israel as their base camp because of Amsterdam.

If you are curious, the diamond cutting industry in Amsterdam still employs 8,500 people, scattered in 80 workshops, but all of them are members of the diamond cutting technicians union, which is maintained by strict regulations. A C in the 4C standard is still firmly in the hands of the Dutch, and this C is one of only two objective standards in the 4C standard. "So, do you want to buy a diamond ring? The diamond processed by Gassan has 121 facets, which is a popular item on the market." The large-tonnage lady drew me back from distraction. I looked at the 25,000 euros diamond ring I picked up for a while, but fortunately I still reacted and rejected it in time. The big-tonnage lady shrugged, apparently she had already seen that I was a messy waiter

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