Diamond Cut – What Is Diamond Cutting

One of the 4C standards of diamonds 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.

Diamond Cutting
Diamond Cutting

The Way Of Diamond Cut

For brilliant cutting, the standard cutting method is 57-sided cutting.

Please refer to the 4C [2] standard of diamonds for the titles of the following parts:
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 facets
Girdle: The widest part of the diamond is also the junction between the crown on the top of the diamond and the pavilion underneath. The girdle is used to fix the diamond when inlaid with jewelry.
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.

The following common cutting methods for brilliant cutting

For diamonds of the same size and clarity, apart from highlighting their classic processing techniques with inlay methods, brands have gradually used unique cutting methods to illustrate their cutting skills. Novel cutting methods can be patented. However, it is hard to say how novel it is, but it is a combination 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 sparkles, diamonds presented by different cutting methods have different levels of sparkle. 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 mechanical and technical requirements, the more expensive the price is generally. 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.

The Technology Of Diamond Cut

The first diamond to appear on the ring was a rough natural octahedron shape. From about the fourteenth century, people processed diamonds before setting them. 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. It lasted 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, Antwerp’s diamond cutter Marcel Tolkowsky published his cutting ratio based on the refractive index and dispersion rate of the diamond, which was welcomed by the general public. Although today’s brilliant cuts have been improved, most of them are still based on Based on the ratio calculated by Tokoffs. However, diamond cutting is a product of the combination of art and technology, which requires long-term accumulation of experience and talent training. Therefore, diamond cutting is mainly concentrated in those traditional cutting centers. Currently, there are four main cutting centers in the world. Mumbai in India, New York in the United States, Antwerp in Belgium, Tel Aviv in Israel. In addition, Thailand, China, Russia, and South Africa 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. That is, the “Russian workers” diamond does not necessarily mean that the diamond was produced by a Russian processing factory. 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).
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 to make the diamond radiant. 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 Indian ink to mark 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 clamp, and the saw disc rotates at a high speed 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, emerald, etc. Or other special shapes. 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 of the above processes. This depends on the characteristics of the diamond blank and the goal to be achieved. For example, the aforementioned “flat” diamond blank may not need to be split. Processing emerald diamonds does not need to go through the process of “rounding”. 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 the full brilliance 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. It is very clear to show the specific positions of the above facets of the diamond: Well, when we see this picture, we know very clearly. Some people always say why there are 57 faces and some 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 a classic lathe, which is a very classic and perfect cutting method. The value of the above 57 faces directly affects the quality of the diamond cut. Therefore, we call the diamond cut with the most standard ratio within a certain value range as “perfect cut”, that is, “IDEAL CUT”. Under the numerical standard, it 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.

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