Raw diamond, as they are found in the mines, does not sparkle and does not have the capabilities of reflection as we know in polished diamonds, such as those which are used in jewelry. But how does a raw, beauty-less diamond become a bright diamond, which breaks rays of light in such a wonderful and beautiful way?
The transformation process of a raw diamond into a polished diamond begins at the selection stage: this is the stage at which we look at the rough diamonds and decide which of them will be used as ornamental diamond, that will be designed for jewelry, and which will be intended for industrial use. Low-quality diamonds and diamond which shape is not suitable for polishing will be used as industrial diamonds. Some are made into diamond powder, which will eventually be used for the polishing process.
Diamonds that will be used as ornamental diamonds go through a scoring stage. This is the stage at which the shape and the flaws of the diamonds are examined, and a decision is made on the optimal cutting of the diamond (round, square, marquise…). The diamonds are not always processed as they are; sometimes a decision is made about sawing and splitting them. Sometimes during the scoring process an “opening of windows” is performed, a term that refers to little polishing at certain points in order to get a glimpse into the stone, and to plan the further work that is to be done on it. There are cases at which the shell of the stone is completely impermeable and we are not able to see what is going on inside the stone without opening of windows, and so the scorer will be able to plan further work, it is necessary to perform an opening of windows.
The scoring process is usually done with the goal of achieving the largest, cleanest and with the highest and the most valuable level of color diamonds. Actually, what happens here is a process in which we examine the raw diamond and identify flaws in order to try to get rid of them at the polishing process, and yet not to lose a lot from the diamond’s weight. In the past, this was done purely visually and using a magnifying glass and other hand tools, but in recent decades there have been very large changes in the field and now imaging devices are used to help determine the ideal way of cutting to maximize the value of the diamond.
The planning and marking of a stone in preparation for polishing or cutting is done with a special marking pen, and advanced imaging equipment, all developed by Israeli companies “Sarin” or “Ogi”. The use of laser and imaging technologies have made the whole process more accurate, with which results can be achieved that until a few years ago were considered impossible. The diamond industry has managed to increase its profitability with better utilization of rough diamonds and diamond consumers got more beautiful, higher quality and larger diamonds.
The third stage, if needed, is cutting or splitting. Cutting is done using a laser beam or a saw, and splitting is done with a barrel and a knife. Of course, laser technology allows cutting at any angle, making the process more efficient. The fourth stage is the stage of polishing which is done according to the guidelines of the scorer and the gemologist. The process of turning a raw diamond into a polished and sparkling diamond holds many challenges: first and foremost it must be remembered that the diamond is the hardest substance in nature, which makes it very difficult to work with and create smooth sides. It is also effective to the direction of polishing, and the optimal direction must be taken into account.
The development of methods for polishing
Diamond polishing is an art that takes time and professionalism. Polishing diamonds incorrectly can cause considerable damage and may create diamonds of poor quality and low value. There are different types of polishing methods that were developed over the years and have become more and more complicated. Today there are several common methods for cutting diamonds, and there are different variations of those methods:
Brilliant polishing– This polishing method was developed in 1919 by Tolkovsky, a Jewish Belgian diamond merchant and mathematician who has developed a model with 57 sides. This model of cutting marched the diamond industry one step further; it made it possible to take advantage of small diamonds. Tolkovsky’s model remains relevant to this day even though it went through changes in proportions (board size and height of the crown surfaces). This diamond cut has around and cone-like look, but it also has different variations. Variations of this method of polishing are heart, oval, pear and marquise-cut diamonds. The heart-cut diamond is a type of polishing that gives the diamond the shape of a heart. This method is not acceptable in very small diamonds because it is hard to distinguish the shape of the heart.
Emerald polishing– Emerald polishing uses parallel polished strips around a central structure of a square or a rectangle. It got the nickname “Emerald” because it was commonly used on emeralds, but it is definitely suitable for polishing diamonds. It has less sparkle compared to the “Brilliant” polishing, but it has its own uniqueness and it emphasizes to the cleanliness of the stone.Radiant polishing- A relatively new polishing method that creates an octagonal-shaped diamond, which means a diamond that has eight sides (they don’t have equal length, but the diamond is symmetrical). This diamond has 70 sides and it comes in the form of a square or a rectangle with an elegant and unique look.
Princess polishing– It is a method of cutting diamonds with 4 sides. In many cases, it allows maximum utilization of the surface area of the rough diamond. Diamonds polished this way have a great reflected ability, to the point at which small defects are swallowed up in it and are not visible.
Cutting methods of the Old World (Old Cut)
Before Tolkovsky, diamond cutting methods were very different from what we see today. They primarily were the result of technical difficulties in diamond cutting, which forced the use of much simpler mathematical models:
Point cut– Cutting method from the 14th century, sourced in Nuremberg, Germany. This cut looks like two square pyramids that touch each other at their base. These diamonds were eight sides, relatively simple a cut compared to Tolkovsky cutting.
Table cut– This is a development of the previous method, probably from the fifteenth century. This cutting is very similar to the point cut; only the vertex of the pyramid was lifted a little above its midpoint.
Old single cut – Again a polishing that is an evolution of the previous method. Very similar to the Table cut, only there are 4 more sides.
That is how the methods evolved, and we got the Peruzzi method, the Mazarin and the European style, each method an evolution of the former, only with more sides.