“What is artistic cutting and how to evaluate it?”
Some aspects of the evolution of stone cutting
Slide 1: Enough has already been said about quality cutting. I think everyone already understands what quality cutting is. But the quality scale isn't discrete—it's continuous, and several questions arise. How does a quality cut differ from a high-quality cut? How and by what basic criteria can we evaluate quality to determine with a high degree of certainty how good a cut is? How can we define a reasonable limit in the pursuit of perfect cutting and meticulous evaluation? Why are today's cutting quality assessment systems imperfect? How can we make cut quality a real factor in determining a stone's price? Detailed answers to each of these questions deserve a separate presentation. Allow me, to the best of my limited abilities, to provide a brief overview of these topics.
Slide 5 (Commercial polishing – average) I'll start with what we have today. Currently, the GIA's diamond grading system is considered the standard in the market; others reproduce it with some changes or additions. Part of this system is the cut grade, which consists of three criteria: brilliance, proportions, and finish. There are five grades for each criterion — from "poor" to "excellent." Strictly speaking, each grade covers a certain range on a continuous scale of quality. For example, the "Very Good" grade includes all intermediate values — from "Not quite very good" to "Almost excellent." Slide 4 (Commercial polishing – good) However, the boundary values of each such range are very conditional and depend more on the lighting conditions and the expert's mood than on the objective characteristics of the stone. For example, are two scratches on the facets already "Good" or still "Excellent"? What if there are four scratches? And what if four are tiny and two are large? And how large are they? And so on.
Slide 3: Then other questions arise: which criteria should be considered more important? Which cut is of higher quality: one that is proportional but with poor polishing and uneven facets, or one that is symmetrical, with mirror-like facets, but with a window? And even simpler: what is better - G-VG-Ex or VG-VG-VG? And what about asymmetrical shapes?
Just yesterday, these questions remained unanswered. Or rather, they simply didn't arise. Even in the strictly regulated diamond market, where every possible variety of cuts is squeezed into a few standard shapes, cut quality has virtually no impact on price. And the Rapaport table, the de facto global price standard, considers only three of the four Cs: carat, color, and clarity. Of course, there are always exceptions. Just as in the diamond market there's Sir Gaby Tolkowsky, whose cut is never the same, so in colored stones there's, say, Michael Daiber, whose every stone is a masterpiece. But these drops don't yet constitute a storm, although they foreshadow one.
Slide 6: Evolution is irreversible. It has many paths, but only one direction. The gap between the quality of jewelry craftsmanship and the stones used in them is becoming increasingly obvious today. With the development of technical means and equipment for cutting, it becomes possible to produce higher quality stones without significantly increasing labor costs. More and more enthusiasts are emerging who are ready to create beautiful stones. And – most importantly! – buyers are appearing who are willing to pay more for superior products in which exquisite design and impeccable execution are harmoniously combined with the perfection of the stone cutting.
Slide 7 But where is the reasonable limit to this perfection? Once upon a time, jewelers managed without any optical instruments at all. Then magnifying glasses came into use – with increasingly higher magnification. Now more and more craftsmen are starting to use microscopes. But, it would seem, why use expensive equipment and technologies; why spend time polishing each prong under a microscope if the consumer won't even see the difference? The classic advertising question: "If you can't see the difference, why pay more?" But something is driving jewelers to acquire microscopes. Why did ancient weavers make 600 stitches per square centimeter, even though the eye can only see about eighty?
Slide 8 I often hear questions like, "Who needs such polishing and such precise facet cutting? Nobody will even see it anyway!" But that's not true. Our eye is a perfect optical instrument. It sees many details that the brain doesn't have time to process consciously, but which act on a subconscious level, creating an impression. Sometimes, of two very similar stones, one won't even attract attention, while the other will make you want to pick it up and never let go. That's how the body responds to its harmony. And harmony, and its consequence – the impression it creates – is a serious enough argument for increasing the price.
Slide 9: So how exactly do we assess the quality of a cut when we're talking about such high levels – the levels of tomorrow? We, dear fellow gemologists, must know the answer to this question today.
Slide 11 When I defined my place in the market segment of custom artistic gemstone cutting, of course, I had to think about how to confirm the merits of high-quality cutting. My cut grading system was based on the judging criteria of cutting competitions held by the American, Australian, and Russian guilds of gem cutters. This system has similarities with others, but also significant differences. Its essence also boils down to evaluating symmetry and polishing, although the "Proportions" criterion was excluded. Indeed, why confine craftsmen and consumers within the framework of standards if the cut design may предусматриate something different? Moreover, this applies not only to the shape of the stone, but also to its height. For example, I came across a ring from the SCAVIA company with a royal sapphire, the length and width of which were 10 millimeters each, and the height of the pavilion was 14! This height was emphasized by flat vertical aquamarine inserts under the prongs – and both the ring and the stone looked wonderful! Instead of "Proportions," the criterion "Optics" was introduced, covering undesirable optical effects caused by improper cutting. The "Symmetry" criterion was also transformed: instead of the overall symmetry of the stone, pairs of facets symmetrical relative to one or two axes are evaluated in accordance with the stone's design.
Slide 13: So-called "Finishing" is given closer attention. It is divided into three criteria: a) integrity of the facets – assessing the presence of polishing defects, additional facets, and inclusions reaching the surface; b) integrity of the edges – the presence of chips and lack of sharpness; c) integrity of the vertices – again, the presence of chips and failure to meet at the points where they are intended by the design. Here, a meeting point is understood as a point where four or more facets converge. All defects are counted and summarized in a table, then – taking into account the assessment of symmetry and optics – an overall score is calculated on a 100-point scale with accuracy to the third decimal place.
Slide 14 The result obtained allows us to classify this stone into one or another quality class of cut. This classification is still provisional; it still needs to be tested by time and market conditions. Currently, it includes three quality classes, each of which is divided into three subclasses. For the two lower classes — Commercial and Quality — the subclasses are designated by numbers (Commercial-2, Quality-1), while the subclasses of the highest class — Elit — have their own names: Elit-Premium, Elit-Extra, and Elit-Ideal.
Slide 16 To confirm that a stone belongs to a particular quality class, both traditional methods (various expert opinions, certificates) and unconventional ones can be used, such as marking the stone's surface. This technology was recently developed by our specialists. Slide 17 Unlike other methods (such as Forevermark), where a concentrated ion beam graphitizes a surface area, which is then etched to create a relief image, this technology involves embedding plasma particles into the surface layer of the stone, without damaging the surface, but only locally changing the optical density of the medium. As a result, the refractive index changes, and the pattern becomes visible when light is reflected from the facet by an external source. The intensity of the irradiation can be adjusted so that the mark can have varying brightness – from clearly visible to practically invisible, noticeable only when water condensation forms on the surface (Breath-test, as jokingly called by Dr. Shigley from GIA).
Slide 18: A weak point in certification is the inability to confirm the certificate's correspondence to a specific stone, especially for standard cut shapes. Photographs in certificates cannot be used for precise identification, nor can dimensions and weight. Therefore, such a practically invisible mark that does not damage the stone and does not affect its gemological characteristics is perhaps the most convenient means of identifying a certified stone today.
But let's return to the topic of gemstone cutting. Elite-grade cutting is almost absent from the market today. But this is not because no one wants to buy it due to the high price. Slide 2 In almost any market, including the jewelry market, there are niches for different price categories of goods, which may not differ significantly in appearance. There is a niche for "commercial" quality goods of artisanal production, there is one for high-quality factory-made products, there is one for well-known brands, and there is one for unique masterpieces of the highest quality. The difference in prices is significant. The market for cut gemstones is no exception.
Slide 19 Let me reiterate: evolution has many paths, but only one direction. How difficult the path of evolution for faceted stones will be depends largely on us. If we ourselves believe, and then can convince market participants – both sellers and buyers – that a different approach is needed to the quality of cutting for simple jewelry inserts, which serve only as a means of decorating the product and realizing the author's design, and for stones, most often expensive ones, which serve as the basis for forming that design. Slide 10 (A Drop of Compassion) Agree, it's nonsense when the base – the most important thing around which the entire product is built – sharply contrasts in quality of execution with the product itself, and not for the better. And it is we, as gemologists, who need to explain why it is necessary to pay for the quality of the cut and how to correctly assess this quality. Today, cutting brands have already appeared on the market. In the New World, these are Michael Daiber, Dalan Hargrave, John Dyer, Jeff White, Tomo Karino. In Europe, masters from Idar-Oberstein traditionally set the tone, and in Asia, the baton has already been picked up by companies such as Nomad, Vitalit, Leopard Gems… For now, they simply produce high-quality cuts, empirically increasing the price of the stones. But it will be a great help to them if we offer them a convenient and effective mechanism for calculating and justifying the price of the cut. Slide 20
