The SA Cut Diamonds guide to the complex art of diamond cutting
As part of our mission to give customers a full understanding of diamonds and the strange industry that produces them, we have compiled a unique guide to the cutting process.
At SA Cut Diamonds we find that our customers always underestimate the complexity of diamond cutting. Nowhere will you find a more up-to-date explanation of this secretive and highly skilled procedure that is often passed from generation to generation.
We hope that you find this guide interesting and helpful when choosing your diamond. Many customers consider the carat, colour and clarity of their stone but ignore the 4th ‘c’ – the cut. How well your stone is made can have a far greater impact on its life and sparkle than small differences in colour or the size of imperfections that are difficult to see.
A diamond is the ultimate hand crafted product. On its way to being cut and polished every one of our diamonds has passed through many unique assessments and processes performed by professionals with minimum five year apprenticeships before being trusted with even the smallest diamonds.
Virtual diamond manufacturing tour
Diamond cutting is a multi-tiered chain system of manufacturing manned by highly skilled individuals who have been through lengthy apprenticeships before they are able to work on even the cheapest of stones. It is these artisans who determine how well a diamond is cut and in turn, how much the finished stone will sparkle.
A rough diamond can come in any shape and it is this that initially gives the marker an idea about which shape diamond will be cut. The marker must then look into the diamond using a 10x magnification loupe to pinpoint where the impurities are in order to envisage the clarity of the final diamond.
The most important tool for a marker is a very high tech piece of lazer scanning technology which, combined with advanced diamond planning software, helps the marker plan to the nearest micron the size and position of the cut diamond that can be extracted from the rough. Using this technology to pinpoint exactly where the impurities lie in the stone, and then manipulating a ‘virtual model’ of a cut diamond that is superimposed into the rough diamond, the marker can predict to the nearest 0.001 of a carat what size diamond can be cut and balance that against how many impurities will be left inside. Lazer lines are then burnt into the surface of the diamond to help guide the diamond cutters through the cutting process.
The first piece of diamond that is cut is the largest facet of the finished stone which is its table. The diamond is cut by securing it in a tang (a diamond clamp) and then rubbing it onto a spinning metal wheel (skaive) that is impregnated with diamond powder. On average 60% of the rough diamond is cut away, disappearing into dust in the air!
In the next process the stone is cut into its final outline shape. This is known as bruting and is achieved using a machine that gently rubs two diamonds together whilst rotating them until they become round. With fancy shapes, a tang is used to put hundreds of small facets on the outline of the stone (its girdle) to achieve the look of a perfectly shaped stone.
This is where the main facets are polished onto the stone, giving it the basic look of a cut diamond.
During this stage the absolute final diameter of the diamond is achieved. This is a vital stage because if the stone is overcut in this process even by a few microns it can have a huge impact on the final weight that can be achieved and, therefore, a drastic impact on the value of the diamond.
Having cut the stone to its exact outline shape and diameter the cutter now cuts all of the main facets of the stone on at their final angles. It is this stage that determines how much life the final stone will have. Remember that the reason a cut diamond sparkles is because the light that passes through the top of a diamond is reflected perfectly around the stone and then back out through the table. It is the combination of the angles of all of the facets that determines how perfectly this reflection occurs and thus whether a diamond is well manufactured. In the trade this is referred to as the cut grade and critically influences how much a diamond will sparkle.
This is the final stage of the manufacturing process where the final small triangular facets are polished onto the stone to give the diamond its true sparkle.
In between each of the processes described above the diamond passes through a quality controller who examines the stone to ensure that every facet is polished to a perfect finish and then, using a similar technology to that used by the marker, that every facet is at the perfect angle to maximise light refraction and ultimately to maximise the brilliance of the polished stone.
SA Cut Diamonds only sources its diamonds from one factory in South Africa which is renowned as one of the most technologically advanced factories in the world and only produces stones polished to the most exacting of standards.
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