What is a Precision Cut Gemstone, and Why is it Important?
Not many people are aware of the differences between precision cuts gemstones and other native cut stones. Nonetheless, with a bit of knowledge, those differences become noticeable. This article is aimed at helping you spot the difference between a precision-cut gemstone & a native cut gemstone and highlight the importance of precision cuts.
Precision cut machines were only recently introduced, and since, they have revolutionized the world of gem cutting. These machines allow the cutter to unveil the beauty hidden beneath the surface of any stone. The results are astonishing. Over 95% of colored gemstones are still cut using traditional machines and technology despite this technology being readily available.
The refractive index is an angle of the stone that corrects the bend of the light when it passes through. Using the correct refractive index allows the light to reflect back 100% and fully exit the top of the stone or the table, and thus, giving the stone the highest possible shine.
Because many native cut gemstones are cut using old technology, they cannot achieve the same brilliance, as they cannot cut the stone at the correct refractive index. This incorrect refraction index means the stones appear dull and lifeless, as they will only reflect a fraction of the light. These stones may be cut deeper to retain weight, as gemstones are sold by carat weight. While other times they are cut too shallow, and light passes straight through the stone.
There are several factors a gem cutter must take into consideration when cutting a stone. All these factors will help optimize the beauty and value of the stone. Every natural gem is unique in color, clarity, size, and other physical characteristics. Therefore, not every gem can be cut the same, nor can they be precision cut, as each gemstone requires special attention and treatments to elevate it to its true potential beauty.
Achieving the most beautiful stone is a delicate balance between the ideal cut and how all the above factors impact the potential beauty of the stone. Every cutter is looking to optimize the beauty and value of the final product, even if it isn't easy to achieve.
Precision Cut vs Native Cut Gemstones
Most colored gemstones, especially three out of the four precious stones (ruby, sapphire, and emerald), are rare. Some are so rare that there are only a few examples in the world. Besides their rarity, the percentage of high-quality pieces extracted from any mine is small compared to the whole yield. Therefore, finding a high-quality colored gemstone is a rarity and one that should be treasured.
It is because quality colored gemstones are so rare that cutters try to preserve as much of the rough material as possible. The per-carat value of these stones is extraordinary, thus saving just half a carat can significantly change the value of that stone and the reputation of the cutter.
Perfection In Cut
However, to achieve this preservation of rough material, the cutter will have to sacrifice other factors. For example, the shape of the finished stone will be based on the profile of the rough material. That is why it's extremely rare to find large colored gemstones, as they tend to yield ovals, cushions and pear shapes. There is also a massive risk of bad cutting. Any bad cutting can affect the beauty, and thus the value, of the finished stone.
Many people in the industry use the term Native Cut to refer to cutting ills that can result from an overenthusiastic attempt to preserve carat weight. It is also used for stones that are cut with more rudimentary machinery than precision cut machines. One of the most frequent flaws of this form of cutting is known as windowing. This is when a stone is cut with a shallow pavilion and a large face or table, allowing light to pass completely through the stone and leaving an area of faded color in the center of the stone. Because light passes through and doesn't reflect, these gems are dull and lifeless, lacking brilliance.
The cut of a diamond is significant. However, it is less so in colored gems. What matters most in the world of colored gemstones is the other three of the four Cs on which a stone is valued (color, cut, clarity, and carat). They are valued on color and clarity above all else. The cut should only enhance these two aspects of the stone. Therefore, the cut of a colored gemstone can be adequate. Adequate means that the stone is cut with the correct proportions and a centered culet, and there should be no signs of windowing or extinction.
Extinctions are dark areas in the stone where no light is reflected.
Precision cut machines allow precise control over each facet of the stone and its angles. These machines produce excellent results and require less skill from the cutter, as the digital machine will do the work. But make no mistake, precision cutting cannot compensate for low-quality rough material. Everyone in the industry knows that an adequately cut gem from finer material will be higher in value than a precision cut from inferior material.
Cutters will sometimes purchase gems that are poorly cut but are high-quality material. They do this when they believe the stone can be salvaged, thus improving the brilliance and removing any windowing, bringing the stone closer to its potential beauty. The main issue with re-cutting a stone is that some weight will inevitably be lost.
Buying a recut stone will always be more expensive, but buying a poorly cut gemstone will undoubtedly lead to disappointment. A high-quality precision cut gemstone will always be a good investment and will hold its value so long as it is kept in good condition.