“I wanted to get your advice on this rings GIA certification. the price seems too good to be true. Is there anything you can see on the Certification that might raise some suspicion? The diamond is on Zoara’s website and is under the catalog ID # D11179161412” – H.R.
The price for the 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara is right on target, for a “GIA Excellent cut diamond” which is not actually cut to the best proportions; which is a concept that might seem confusing at first, but suffice to say that I find the parameters for the GIA Excellent cut rating to be rather broad.
Note that the same 1.21 carat, I-color, Internally Flawless clarity, round on Enchanted Diamonds, received a cut score of only 65% on their in-house proportions based grading scale, as indicated by the red arrow that appears on the graphic to the left. Since this diamond has an overall cut grade of GIA Excellent, you might be wondering how accurate is the Enchanted Diamonds cut score feature?
Well let’s take this diamond apart piece-by-piece, section-by-section, and break it down so that you can understand why this GIA Excellent cut diamond scores so poorly on the Enchanted Diamonds cut score provided on their diamond listings.[separator]
Before we get started on a more in-depth review of this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara and I explain why it only scored 65% on Enchanted Diamonds in-house cut score, I’d like to provide you with an outline of the proportions that I look for in a round brilliant cut diamond:
This extremely tight range of crown and pavilion angle, combined with the overall cut grade of GIA Excellent or AGS Ideal-0, and an exceptional level of optical symmetry, will systematically produce round brilliant cut diamonds which exhibit an extremely high volume of light return, and a virtual balance of brilliance (white sparkle) with flashes of light / sparkle that are bold, bright, and vivid.
This range of crown angle, and pavilion angle, and the length of the lower girdle facets is obviously based upon my personal preferences for how I expect a round brilliant ideal cut diamond to look; the degree of light return that I like to see in a diamond; and the type of sparkle that I prefer…
* Crown angle variances: the range stated is likely to provide a virtual balance of brilliance and dispersion, however a slightly broader range of crown angle is also acceptable, such as the range of 34.0 – 35.0 degrees, provided that the pavilion angle of the diamond is adjusted appropriately; this is a topic worthy of an entire blog post, but feel free to run options past me via my free Diamond Concierge Service.
* Pavilion angle variances: I tend to be extremely strict about the pavilion angle, since it is the surface on the diamond which is the primary indicator of light return by volume; thus I might go as low as 40.5 degrees, provided that the crown angle is a suitable offset; however I am not likely to ever recommend a diamond with a pavilion angle steeper than 41.0 degrees, not 41.1 degrees, not 41.2 degrees, my upper limit really is only 41.0 degrees!
* Lower girdle facet length variances: I personally prefer round brilliant cut diamond that exhibit broad spectrum sparkle, however you might prefer diamonds that exhibit sparkle which is more like pin-fire, as opposed to broad spectrum sparkle; in which case you can use the same proportions recommended above, but look for options that have lower girdle facets in the range of 80 – 82% instead of 75 – 78% as I prefer. Notice that my range does not include those diamonds with lower girdle facets that are 79% in length, and that is because it is essentially the transition point where things can go either way.
In order to understand why I feel the proportions of this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara are undesirable, despite the fact that the diamond received an overall cut grade of GIA Excellent from the GIA Gem Trade Laboratory, we need to determine how the proportions of this diamond would be ranked if the diamond were to be graded by the American Gem Society Laboratory (AGSL) for proportions.
To do this, we open up the AGSL Proportions Chart and wander down to the grid provided for round brilliant cut diamonds with a 61% table diameter, as indicated in the upper left corner of the graphic provided by the AGSL below.
Then you simply locate the column for diamonds with a 34.5 degree crown angle, and the line that represents diamonds with a pavilion angle of 41.6 degrees, and then draw two lines to find the axis where those two factors meet, and that indicates that a diamond with these proportions would not be graded by the AGSL as any higher than AGS-2 Very Good for proportions; which means that it could also be graded lower for overall cut grade, depending on how the diamond fared during the Angular Spectrum Evaluation Technology scan relied upon by the AGS Laboratory to determine the Light Performance of diamonds.
So perhaps you now have a better understanding of why the same 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara was listed with Enchanted Diamonds with a Cut Score of only 65%.
And I happen to concur with the Enchanted Diamonds cut score for this particular1.21 carat, I-color, Internally Flawless clarity, round on Enchanted Diamonds because if you refer to my preferred list of proportions that is provided above, you’ll see that the table diameter of 61% is well beyond my preferred range of 53 – 58%.
And while the crown angle of 34.5 degrees is well within my preferred range of 34.3 – 34.9 degrees, the crown height of 13% is extremely shallow for that crown angle; by my standards it should be closer to 14 – 15%.
And the pavilion angle of 41.6 degrees is way, way, way too steep! It is clearly way beyond my preferred range of 40.6 – 40.9 degrees, and when combined with a pavilion depth of 44.5% it is likely that light is not striking off of the pavilion facets properly, which would reduce the volume of light return significantly when compared to GIA Excellent cut diamonds that have proportions within my preferred range of selection criteria.
There is one other thing that I want to address about this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara, and that is the fact that they have the diamond listed as being a “Hearts and Arrows diamond” based upon the line that reads “Hearts & Arrows” which is highlighted by the red arrow on the graphic pictured to the left. As one of the original importers of Japanese “A” Quality Hearts and Arrows diamonds into the United States back in the mid-1990’s I happen to find the suggestion that this diamond might qualify as a hearts and arrows diamond to be patently offensive and misleading. This statement might get me kicked out of Zoara’s affiliate program, but that could be fun also![separator]
Given what I’ve already said about this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara, and what I’m about to say about what I think about the concept of hearts and arrows diamonds that they seem to be operating from, just imagine what I might say if I weren’t actually affiliated with Zoara diamonds! Oh man, the gloves could really come off them! Bah-ha-ha-ha-B-wah-ha-ha-ha !!! Numerical data, photographs, and mathematical ray tracing don’t lie! Diamond visual performance is mathematically and systematically predictable.
It goes without saying that I saved a screenshot of the definitions of H&A Diamonds provided by Zoara Diamonds in the Hearts and Arrows Diamond Buying Guide (pictured left) just in case I need it for posterity. I want to point out that almost everything that I’m about to say, has been revealed by Zoara Diamonds right here on this page! So it’s almost like I’m simply reminding Zoara of what their standards are for Hearts and Arrows diamonds, starting with “The term “Hearts and Arrows” refers to round brilliant diamonds with the facets arranged so that eight symmetrical arrows appear in the face-up position and eight symmetrical hearts appear when viewed in the table-down position.”[separator]
Now I ask you, does the hearts pattern pictured on the example of a hearts and arrows diamond provided by Zoara on their Hearts and Arrows Diamond Buying Guide, look symmetrical to you? Because I don’t see a single heart that I would describe as being “symmetrical” as compared to any of the other hearts. There are eight hearts, but not one of them matches another heart, and thus this pattern of hearts is unsymmetrical by definition, and therefore this diamond could not possibly be deemed “Hearts and Arrows” by the standard which Zoara has described above; and we’re talking “GAME OVER” if we attempt to apply my grading standards to the equation [BUZZER sound].[separator]
The only object that I see in the scope image provided by Zoara (above) as an example of what a hearts and arrows diamond is supposed to look like, that looks anything like a heart by my standards, is the one located in the relative eleven o’clock position; however all of the other “hearts” look more like lawn darts to me… and lawn darts, rabbit ears, or anything else that doesn’t clearly resemble a crisp and complete, symmetrically shaped heart, which matches all of the other hearts that are present within the diamond, does not make a hearts and arrows diamond.
And if we’re going to be technical, that split in the cleft of the heart located in the relative eleven o’clock position, that you see getting larger and larger, and which runs deeper and deeper into the hearts, as you move your eyes around the stone in a clockwise direction; and the irregularity of the lawn darts pattern pictured above, would be the result of irregularities in the length and shape of the lower girdle facets, and the indexing of those facets as they are placed around the pavilion of the diamond; but you’d probably have to be an expert on the subject of hearts and arrows diamonds to recognize something like that.
The very first line of text that appears under the heading “Hearts and Arrows” on the Hearts and Arrows Diamond Buying Guide provided by Zoara on their web site reads:
“The term “Hearts and Arrows” refers to round brilliant diamonds with the facets arranged so that eight symmetrical arrows appear in the face-up position and eight symmetrical hearts appear when viewed in the table-down position.”
So I imagine that when we look at the photograph of the “hearts and arrows diamond” that they provide above on their Hearts and Arrows Diamond Buying Guide, that they are referring to something like the hearts pattern exhibited by the 1.245 carat, I-color, VS-1 clarity, Brian Gavin Signature round diamond that is pictured to the left; because this diamond exhibits a hearts pattern that looks symmetrical to me; I clearly see eight symmetrical hearts, which are relatively even in size, and which are uniform in shape, with no bending of the tips, nor are any substantial splits visible within the clefts of the hearts; which indicates an exceptional degree of optical symmetry and diamond cut quality.[separator]
It might not surprise you all that much, to learn that the range of proportions that is an integral part of my diamond selection criteria, happens to be the range of proportions which is most likely to yield a crisp and complete pattern of hearts and arrows; when those proportions are combined with an exceptional degree of optical symmetry… because hearts and arrows diamonds don’t just happen by accident, they are planned from the moment that the diamond cutter first evaluates the diamond rough using state-of-the-art computerized diamond rough analysis equipment, and each facet must be precisely shaped, and polished on to the surface of the diamond with an extreme level of precision.
As you might imagine, there is also state-of-the-art diamond analysis software available that makes it possible for diamond buyers to use the proportions of a diamond like this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara to estimate the light return and visual performance of a diamond, using mathematical ray tracing analysis. This software will not only accurately predict how light will travel throughout the diamond, but also where it is likely to exit the stone, and how the diamond is likely to look when viewed through the reflector scopes used to grade cut quality.[separator]
Most of the vendors who I work with who sell Hearts and Arrows super ideal cut diamonds, provide actual photographs of the diamond as seen while unmounted through the various reflector scopes that we use to judge diamond cut quality, such as an ASET Scope, an Ideal Scope, and a Hearts and Arrows Scope; however Zoara did not provide these images on the diamond details page for this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara, they merely referred to the diamond as a “Hearts & Arrows” 3X “Triple-X cut” diamond; so I thought that it would be interesting to see what the program thinks a round brilliant cut diamond with the following proportions would look like:[separator]
And honestly I have to admit that the diamond is likely to exhibit a better pattern of lawn darts than I initially anticipated, this is the computer rendered image of what the 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara is likely to look like when viewed while unmounted through a hearts and arrows scope. Interestingly enough, this image is not that much different from the image provided by Zoara in their Hearts and Arrows Diamond Buying Guide, I wonder what the proportions and overall cut grade for the diamond happen to be?[separator]
Doh! That’s not good… but it is actually what I expected to see, because of the 41.6 degree pavilion angle and the 44.5% pavilion depth combined with the 13% crown height, and the 61% table diameter. Yes-sir-eee Bob, that diamond is leaking light BIG TIME, as is indicated by the bright white “ring of death” that is visible within the table facet of this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara. The arrows pattern looks more like ping-pong paddles, and there is way too much green around the edge of the stone; and practically zero contrast.[separator]
But this really should not be all that surprising, since the clarity image of the diamond provided by Zoara for this 1.21 carat, I-color, Internally Flawless, GIA Triple Excellent, Hearts and Arrows diamond, exhibits practically zero static contrast. Is it any wonder why this diamond got a cut score of 65% on the virtual listing that I found for this stone with Enchanted Diamonds? It’s a DOG, DOG, DOG, and we’re not talking purebred; I don’t care what it scored at the GIA, I’d love to see this diamond be submitted to the AGS Laboratory for grading under the guidelines of their Light Performance based diamond grading report, which relies upon Angular Spectrum Evaluation Technology (ASET) because we already know that the best it can score for proportions is AGS-2 Very Good, and it would have actually scored AGS-5 Fair on the original proportions based grading scale introduced by the AGSL in 1996.
If you have a keen eye, you might notice that the same white “ring of death” is clearly visible in this computer generated rendering of what 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara is likely to look like when viewed through an Ideal Scope, based upon the proportions provided on the GIA diamond grading report. Compare that to the examples provided on this Ideal Scope Reference Chart and let me know what you think. When I look at the reference chart, the closest match that I see falls under the category of poor light return.[separator]
The image of what a hearts and arrows diamond is supposed to look like, is provided as the main image on the Hearts and Arrows Diamond Buying Guide featured on the Zoara web site. Notice how the arrows pattern that is visible within the diamond pictured in the middle is dark in tone, this indicates that the diamond exhibits a very good degree of static contrast.
I’ve already expressed how I feel about the precision of the “hearts pattern” pictured above, and I probably don’t need to point out that the tips of the arrows are bending in different directions on the arrows pattern pictured to the right… but Zoara Diamonds is absolutely correct in their understanding that the arrows pattern of a hearts and arrows diamond should exhibit a high degree of contrast.
So why does the arrows pattern of this 1.21 carat, I-color, Internally Flawless clarity, round diamond from Zoara look white in this clarity photograph? You get two points if you recalled that I mentioned earlier that the combination of the 41.6 degree pavilion angle and the 44.5% pavilion depth was probably preventing light from properly striking off of the pavilion facets! And do you see how the arrows pattern looks like ping-pong paddles in the clarity photograph provided by Zoara? Ding, Ding, Ding, two points for the mathematical ray tracing software for rendering this puppy up right! There just might be something to the concept of buying diamonds based upon proportions and reflector scope images.[separator]
Now I’m not saying that Zoara does not have any Hearts & Arrows quality diamonds in their inventory that might meet my selection criteria, but they certainly didn’t provide me with the data necessary to make that determination on this particular diamond. I had to fire up a very expensive computerized ray tracing proportions analysis program, and have it calculate the proportions, and estimate how the diamond is likely to appear when viewed through an ASET Scope, an Ideal Scope, and a Hearts and Arrows Scope.
But vendors like Brian Gavin Diamonds, and High Performance Diamonds, who both specialize in true Hearts and Arrows quality diamonds, provide all of the reflector scope images that I need to determine the degree of optical symmetry exhibited by every hearts and arrows diamond in their inventory. So when I look at the details page for this 1.221 carat, I-color, VS-2 clarity, Crafted by Infinity super ideal cut diamond, I can clearly see by the image provided to the left, that it exhibits a crisp and complete hearts pattern; and the arrows pattern is clearly visible in the ASET Scope and Ideal Scope photographs; and their diamonds exhibit incredible static contrast.[separator]
Needless to say, Brian Gavin Diamonds and High Performance Diamonds tend to be the vendors who I refer most often to clients who are looking for the superior light performance and sparkle factor that is provided by a true hearts and arrows diamond, which is cut to the range of proportions that is outlined in my article 15 Seconds to Diamond Buying Success, with an overall cut grade of AGS Ideal-0 and which exhibits the degree of optical symmetry that I insist upon when buying diamonds for inventory.
All right, this article took a lot longer to write than I originally anticipated, so I’m not going to run through every statement made by Zoara within their Hearts and Arrows Diamond Buying Guide that I disagree with; but suffice to say that a few of my friends who live with me here in the outer realm of the universe where Hearts & Arrows Diamonds are considered to be the very, very best, took a look at that page today and laughed their asses off. Perhaps we’ll revisit this subject another day when the holiday season is not in full swing…
Thanks for submitting this diamond for review via my free Diamond Concierge Service, I’ll send you some links to some diamonds from Zoara and other vendors that I do feel are worthy of your consideration, but won’t publish them here so that you can have first crack at them.
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