Our exclusive Diamond Cut Evaluation Index is designed to rate round ideal cut diamonds certified by the GIA. The calculation evaluates the diamond’s light performance with the help of a proprietary algorithm developed by us through extensive scientific research.
Each stone is evaluated in six categories:
- visual inspection
- microscopic examination
- optical index calculation
- market availability
- ring design comparability
- comparative pricing
We evaluate the cut grade of any modern round brilliant based on its GIA data. The index is measured on a scale of 0 to 100. Grades within 5 points are nearly identical and do not indicate any advantage over one another. In practice, the maximum grade rarely exceeds 96-97.
We do not recommend choosing a diamond based solely on the index. Each stone has its own character and beauty. A diamond with a lower index might seem more attractive to some people.
We do not recommend choosing a diamond based solely on the index. Each stone has its own character and beauty. A diamond with a lower index might seem more attractive to some people. The Diamond Cut Evaluation Index comes in handy when you need to break a tie between otherwise identical ideal-cut round diamonds.
The calculation is based on the stone’s table and height percentage and crown and pavilion angles measured by the GIA and printed on the certificate.
The great majority of round brilliants score way below 50. Only a small fraction of round diamonds receive “excellent” -cut, -polish, and -symmetry grades from the GIA. These XXX diamonds score above 50.
A tiny percentage of XXX diamonds with a score of 75 or more are called “super-ideal.” It is not an official term but a part of the trade jargon.
Anyone can request an evaluation of a stone. It is free for clients, but we limit the number of times the reading is done. To discourage multiple requests for evaluations without an intent to buy, we may require a retainer.
Affiliated retailers enjoy free access to the data as well. To find out whether you are an affiliated retailer, please call us.
To find out the score, submit a list of up to five certificate numbers under consideration. In most cases, we can return the results in just a few hours.
Only GIA-graded round brilliants with XXX grades are eligible for the evaluation. Grades and measurements by gem labs other than the GIA are inconsistent and unreliable. Therefore, we strongly advise buying GIA-certified diamonds only.
The index is not a reflection of the stone’s beauty. A human eye cannot distinguish between two diamonds with a close score.
The index is designed to highlight the minute differences in the cut. In combination with the slight price differences, it can help to spot the most attractive stone.
The index is a simple way to break a tie between several nearly identical stones without becoming a gemologist. It will save your time trying to make sense of contradicting and often misleading information found online to pick one diamond.
We will work with you directly and supply the best-looking and best-priced diamond on the market. After all, we guarantee to match or beat the lowest diamond price.
When we hand-pick diamonds for you, we do not rely on the index; we go much deeper. First, we inspect potential diamonds using our exclusive 23-point evaluation system. Then we examine the spreadsheet to spot better-priced stones. Once the work is complete, you get the last say which stone you want.
The Fake Calculator
Holloway Cut Advisor (HCA) is a web-based honeypot collecting personal information under a diamond evaluating system’s guise. The HCA is designed to spy on consumers and to channel potential buyers to affiliated dealers.
- – NOT recognized by any gemological lab in the world
- – NOT used by professionals
- – NOT supported by the scientific community
- – NOT subject to a peer review
Just like the two swindlers in “The Emperor’s New Clothes,” the HCA plays on people’s pride and intellectual vanity by selling a “diamond score” that no one can see.
The imposters, in this case, are the Australian diamond broker and his Russian sidekick. Garry Ian Holloway and Sergey Sivovolenko worked out a scam to substitute the established diamond grading system with their own cockamamie scheme. One is a self-proclaimed diamond guru; the other is a crackpot operative of notorious Russian tech start-up Octonus Software.
They acquired the US patent 7,251,619 for “a computer-implemented system for gem evaluation, and assessment of a diamond appearance based upon the determined values of attributes contributing to the visual appeal and/or the established rating value.”
Sounds like a load of BS? You bet it is!
Not surprisingly, the HCA calculator is hosted by the Pricescope. The Pricescope, for those not familiar with this notorious troll-farm, is a public forum used by a closely-knit group of diamond and gem dealers to promote their own interests.
The HCA creators say they can rate a diamond’s “visual appeal” using a proprietary system. Despite their claim, the HCA is neither groundbreaking nor independent or unbiased. It has no scientific base. HCA is a trap for anal-retentives who think they can outsmart the system.
All ideal cut diamonds look exactly the same; a regular person cannot tell them apart. The subtle differences do not make one superior to another. They are equally beautiful. The Holloway Cut Adviser (HCA) is billed as a diamond-cut calculator. It takes a diamond’s metrics such as total depth, table size, and crown angle. The diamond’s pavilion angle determines 90% of the score.
The calculator also requires a diamond’s weight, measurements, and certificate number. This additional information is collected purely for marketing purposes, and it is not used in the calculation.
Diamonds are scored on a scale from 0 to 10 — the lower the number, the higher the score. Yet, the highest score is not zero but 1.0. Anything less than 1 is also undesirable. The calculator is currently limited to three calculations free of charge; after that, it demands payment.
ASET (which stands for Angular Spectrum Evaluation Technology) is a highly questionable method of measuring a diamond’s “light return.” According to the AGS (American Gemological Society), the test can tell a bad diamond from a good one. In reality, the ASET is used for malicious attempts to misrepresent an inferior diamond by drawing away attention from its inflated color and clarity grades and focusing instead on a whimsical diamond’s “light performance.”
ASET was invented and is performed by the AGS lab. The mind-bending colored stains that would make Hermann Rorschach proud are prominently featured on every AGS diamond certificate. No other labs except AGS perform, use, or recognize this so-called “test.”
Using ASET on any antique cut diamond is like giving a prostate exam to a woman. It makes no sense and serves no purpose.
Reputable jewelers do not use ASET. No Jewelry Trade group recognizes ASET as a legitimate diamond evaluation tool. It’s a scam perpetrated by AGS in their effort to undermine GIA supremacy in the field of diamond grading. A small group of dealers congregating around a fake “consumer” website called Pricescope uses ASET as a marketing tool to sell AGS-graded diamonds.
Much like Turkish coffee reading, ASET requires charismatic storytelling and vivid imagination. To test a diamond, you will need to get the ASET gizmo from AGS or eBay for a fraction of the AGS price.
The cone is colored in a bright green and pink color. The diamond is placed on a clear tray (included) sitting on a light source (your cell phone). Look through the magnifier peephole, and you see the stone in psychedelic colors.
Those who fall for the ASET scam are consumers who trust penpals on the web forums more than they trust qualified and experienced jewelers and diamondaires.
The third stage of every con job is to encourage the victim’s greed. An AGS jeweler does it by hinting that the ASET test uncovered the diamond’s “hidden value,” which ultimately impairs the cheapskate’s rational judgment. It’s an easy racket – the customers have no clue what they are looking for when they stare at the ASET pictures.
When the diamond is lit up from behind, the three colored bands are reflected by the diamond’s facets. You can see the mosaic of colored reflections through the ASET peephole. Depending on their angle, facets reflect the colors of the cone’s wall. According to the AGS, this kaleidoscopic pattern represents a map of a diamond’s “light performance.”
Here is what the colors mean according to AGS pseudoscientific gibberish:
- White is “bad.”
- Green is “sort of bad, but we can twist it around.”
- Red is “good.”
- Blue is “we haven’t decided yet.”
All diamonds leak light. There is nothing wrong with it. The light typically dissipates sideways or goes through the stone. Only poorly cut diamonds leak an excess of light that is a cause for concern. A diamond with an excellent cut by GIA, by definition, reflects all the light necessary to have exceptional brilliance and fire.
AGS claims that the ASET evaluates the “light performance.” Are you buying a Ferrari or a diamond? There is no performance in diamonds, just like there is no performance in paintings. It’s either a well-cut gem or junk not worth consideration. The subtle differences between ideal-cut diamonds should not be evaluated. They are a beautiful scope of diversity, each triple-X diamond slightly different yet as perfect as any other.
There is no science behind ASET; it’s a diamond marketing tool. Of course, they will dispute this and tell you that it is a product of decade-long research, but can you trust the lab that routinely over grades diamonds? I certainly would not.
The ASET was initially intended for “analyzing” round diamonds. Once AGS dealers sensed an opportunity, the racket was extended to fancy shapes as well. Using a round ASET cone on a fancy-shaped diamond is as ridiculous as jamming a square peg into a round hole. Three-card Monte con can be played with any deck of cards.
The effect of the mounting
The difference between good ASET and bad ASET is so minor that it pales in comparison to other factors, such as the dramatic effect a mounting has on the stone. A setting that holds the diamond significantly alters the stone’s optical properties. Even the top stone set into a low-end ring will look dull and less brilliant.
GIA ideal cut diamond (XXX grade) is enough to guarantee a spectacular-looking diamond. You are better off putting more thoughts into the setting.
Regarding the use of the term Hearts and Arrows:
The “Hearts and Arrows” cut is defined as a round brilliant showing a specific pattern when viewed through the “Idealscope” gizmo. All ideal cut diamonds display symmetric patterns, but only one is considered to be superior. The Japanese obsession with quality and precision resulted in diamonds cut so exactly that the shadows of facets produce defined kaleidoscopic patterns.
A small gismo was devised to aid the observation of this effect – the pattern of eight distinct chevron-shaped spots and eight elongated spots visible when the stone is flipped upside down. The original Japanese name “Swords and Shields” was eradicated and replaced by the sugary “hearts and arrows.”
We use only “ideal cut” diamonds, defined as stones with an Excellent cut grade by the Gemological Institute of America. All Ideal cut diamonds display a radiating pattern similar or identical to Hearts and Arrows.
Whether you call it Hearts and Arrows or Swords and Shields™ as we prefer, it simply means that the diamond has an exceptional symmetry.