Hi Todd, I’m looking for picture perfect hearts and arrows diamonds of the highest cut quality, weighing 1.20 – 1.49 carats, D-color, and VVS-1 or higher in clarity. I have some questions about the cut quality of James Allen True Hearts diamonds, based upon a thread I found on Pricescope wherein the ideal scope images of some of their diamonds were called into question. You provided some great advice within the thread, but seemed hesitant to actually evaluate the ideal scope images; is there a reason for that? I’m considering H&A diamonds from Brian Gavin, Crafted by Infinity, and James Allen; may I ask for your top picks and a detailed analysis of the options available? — Ryan P.
Okay so the two diamonds being discussed in the thread on Pricescope and referenced as Diamond #1 and Diamond #2 are as follows:
The question being raised by the Original Poster (OP) who started the thread, pertains to the evaluation provided by the Gemologist employed by James Allen with regards to which diamond provides the best face-up light performance, and the differences between the ideal scope images provided by James Allen for each diamond.
An important factor to take note of is that neither of these diamonds are from the James Allen True Hearts collection, thus they are not likely to exhibit the same degree of optical symmetry that you should expect from a hearts and arrows quality diamond. In addition, the 0.90 carat, D-color, VS-1 clarity, round diamond from James Allen has a symmetry rating of very good, thus it should be expected that the ideal scope image is going to exhibit some inconsistency.
The reason why I did not specifically address the OP’s questions pertaining to the ideal scope images, is because forum rules prohibit trade members from providing advice which is specific to the diamonds of a featured vendor… but there is no reason why I can’t use the images here to provide my clients with guidance and insight into how to interpret an ideal scope image for a round brilliant cut diamond, especially since James Allen is one of my featured vendors.
Diamond #1 referenced in the thread on Pricescope is this 0.90 carat, E-color, VS-1 clarity, round diamond from James Allen which has an overall cut grade of GIA Excellent. The diamond has a total depth of 62.1% with a table diameter of 57% and a crown angle of 34.5 degrees with a pavilion angle of 41.0 degrees and a medium to slightly thick, faceted girdle and no culet. Based upon the numbers, this diamond should exhibit a high volume of light return and a virtual balance of brilliance and dispersion.[separator]
However buying a diamond “by the numbers” is not as easy as simply looking for GIA Excellent or AGS Ideal cut diamonds which have the right offset for crown and pavilion angle, because the measurements for crown and pavilion angle as provided on the diamond grading reports are the average measurements of eight individual measurements taken from each section, and the GIA rounds those measurements off, thereby averaging the average measurements to the extent that I find them to be more or less useless.
Let’s assume for a moment, that the average pavilion angle of 41.0 degrees stated on the lab report is the result of a tight range which consists of a high of 41.2 degrees and a low of 39.8 degrees, it would not affect the light performance of the diamond all that much because the pavilion facets which are the primary reflective surfaces in terms of light return are all cut pretty evenly… but what do you suppose happens if the variance in the angle of those “mirrors” is more dramatic, such as a low of 39.6 degrees and a high of 41.4 degrees? And take note that this would still produce an average pavilion angle of 41.0 degrees…
The answer is that when the lower girdle facets of a round brilliant cut diamond are cut too steep, they fail to catch the light which enters the diamond and direct it back up through the table facet, which is most likely why this 0.90 carat, E-color, VS-1 clarity, round diamond from James Allen appears to be leaking light through the table facet, as indicated by the light grey sections pictured along the edge of the table facet, and by how the eight pavilion main facets are failing to reflect the shadow created by the camera lens positioned overhead, thus the lack of contrast being exhibited by the arrows pattern. Notice how the arrow shafts located in the 1, 7, and 10 o’clock positions are lighter than the others?[separator]
Now look at the clarity photograph provided for the 0.90 carat, E-color, VS-1 clarity, round diamond from James Allen and notice how the arrow shafts are failing to catch the light in the three and nine o’clock positions… now do you see how some of the pavilion main facets are thicker than the others? This is most likely due to differences the indexing of the lower girdle facets which separate the pavilion main facets, and this variance in the static contrast exhibited by the arrows pattern will affect the light performance and sparkle factor of the diamond.[separator]
Now if you’re trying to figure out how a diamond that exhibits this type of difference in the symmetry of the facet shape and size could be graded by the GIA with an overall cut grade of Excellent, the answer is that the labs do not take “Optical Symmetry” into account as part of the overall cut grade… they grade “Meet Point Symmetry” which is based upon how the facet junctions align with each other from facet-to-facet and upon how the facet sections located on the upper half of the diamond, line up with those featured on the lower half of the diamond.
As mentioned previously, this 0.90 carat, D-color, VS-1 clarity, round diamond from James Allen has a symmetry grade of very good. While the ideal scope image exhibits less light leakage underneath the table facet, the arrow shafts exhibit split degrees of contrast, especially in the 9, 10, and 11 o’clock region, indicate a difference in the angle and indexing of the pavilion facets. And if that’s not enough, notice how the tips of the arrows do not align with the point where the bezel main (kite shaped) facets meet at the girdle edge of the diamond. Imagine that this diamond is a jar with facets on the lid and the jar, it’s kind of like the lid was not quite screwed on right.[separator]
In this particular instance, the size and shape of the kite shaped bezel main facets appear to be different sizes based upon the clarity photograph of this 0.90 carat, D-color, VS-1 clarity, round diamond from James Allen which the GIA gave a meet point symmetry grade of very good symmetry. Just look at the difference in the width of the opposing bezel main facets pictured in the eleven and one o’clock positions… this is most likely the reason for the very good symmetry rating, and it is clearly evident that it has an effect upon how the tips of the arrows pop.[separator]
Once again, I want to make it clear that neither of these diamonds are James Allen True Hearts diamonds, thus I don’t expect them to exhibit the same level of optical symmetry that is required for a round brilliant cut diamond to exhibit a crisp and complete pattern of hearts and arrows… but you asked me to expand on the insight which I provided on the thread featured on Pricescope, and I believe that these two diamonds present a wonderful learning opportunity for people who want to know more about the differences between diamonds with very good, excellent and ideal symmetry, as well as providing insight on how to interpret ideal scope images.
This graphic provided by Brian Gavin demonstrates how hearts and arrows patterns are created within a round brilliant cut diamond. Essentially each heart is comprised of two halves which originate from the pavilion main facet located on the opposite side of the diamond, being reflected off of lower girdle facets which are located next to each other. Any variance in the size, shape, or indexing of the pavilion facets will result in differences in the size and shape of the hearts, as well as make it appear like the tips of the hearts are bent due to the length of the lower girdle facets being different lengths, as apparent here in the hearts pictured in the relative 2 and 9 o’clock positions.[separator]
Even though the diamonds referenced above from James Allen have proportions which are generally considered to be ideal cut, it is clear that they are not likely to exhibit crisp and complete patterns of hearts and arrows, because they lack the degree of optical symmetry required to produce a true pattern of hearts and arrows.
One of the diamonds which I think might be of interest to you is this 1.224 carat, D-color, VVS-1 clarity, James Allen True Hearts diamond which has an overall cut grade of AGS Ideal-0 and exhibits a decent pattern of hearts and arrows as indicated by the photograph provided to the left. It is apparent that there are some differences in the indexing of the pavilion facets by the slight difference in the size of the hearts, as well as how the tips of the hearts twist a bit towards the bottom of the picture. In addition if you look at the left half of the table facet in the ideal scope image provided on the diamond details page, it seems like there is a little bit of light leakage underneath the table facet.[separator]
The light leakage which I’m referring to is evident on the left side of the table facet in the form of the light grey areas located along the edge of the table facet from the relative 7 o’clock to 11 o’clock position. The most likely culprit that is causing the light leakage under the table facet of this diamond, is the 43.3% pavilion depth measurement. The crown and pavilion measurements provided on diamond grading reports are based upon the average of eight individual measurements, which can be the result of a spread which is minimal or broad, e.g. a range of something like 43.0 – 43.6% which prevents the lower girdle facets from properly catching the light and reflecting it upwards.[separator]
Despite evidence that this diamond is leaking a little bit of light from underneath the table facet, it did exhibit enough brightness and contrast to earn it an overall cut grade of AGS Ideal-0 from the American Gem Society Laboratory (AGSL) under the provisions of their proprietary Light Performance grading platform which relies on Angular Spectrum Evaluation Technology (ASET) to measure diamonds for brightness, contrast, and other factors of light return… and this is something which the two ninety point diamonds from James Allen were not subjected to because they were graded by the GIA with an overall cut grade of GIA Excellent, which only takes polish, symmetry, and proportions into account, thus this diamond was subjected to a more rigorous grading platform.
This 1.224 carat, D-color, VVS-1 clarity, James Allen True Hearts diamond is easily within the Top 1% of the annual production for round brilliant cut diamonds, but clearly it could be cut a little tighter, because despite the appearance of a decent pattern of hearts and arrows, and an overall cut grade of AGS Ideal-0, it has a pavilion depth which is a bit too steep and as a result it shows signs of leaking some light from under the table facet. It is an option which is likely to be superior to a lot of the options which you’ll find out in the open market, but if you have the time and patience to wait, there are probably more precise diamonds to be found… of course, they’ll probably cost a little bit more, because higher production quality, requires more time and skill, so at the end of the day it all comes down to a matter of knowing what level of perfection is adequate for your personal preference.
The first thing that I want you to notice about this 1.208 carat, E-color, Internally Flawless, James Allen True Hearts diamond, is that the Ideal Scope image, pictured to the left, looks significantly better than the one provided above for the 1.224 carat, D-color, VVS-1 clarity, James Allen True Hearts diamond that I just reviewed. The ideal scope image shows a consistent distribution of pink throughout the diamond, indicating that the diamond is not leaking light under the table facet like the other James Allen True Hearts diamond appears to be.
This diamond has a total depth of 61.2% with a table diameter of 55.3% and a crown angle of 34.3 degrees which is offset by a pavilion angle of 40.8 degrees and it has a pavilion depth of 43.1% which is a much better average pavilion depth than the 43.3% average pavilion depth of the 1.224 carat diamond, and that is the reason the pavilion facets are catching the light properly for this diamond! Hmmm, there might be something to all this geometry!
Unfortunately if you look at the hearts pattern for this 1.208 carat, E-color, Internally Flawless, James Allen True Hearts diamond, it exhibits a fair amount of inconsistency, which is a sign that the indexing of the pavilion facets is slightly off.
Just look at how the tips of the hearts are bleeding into the arrow heads located beneath them, it’s as if there isn’t any degree of separation at all. I’m really beginning to wonder whether there is any kind of consistency within the James Allen True Hearts collection, or if diamonds are labeled “James Allen True Hearts” if they exhibit any sort of pattern at all, because this is not “Hearts and Arrows” by Japanese or HRD standards, not even close.[separator]
As far as I’m concerned, this is just another ideal cut diamond, cut to proportions which represent the center or “sweet spot” for the zero ideal cut proportions rating, which happens to exhibit some sort of hearts and arrows pattern as a result of the basic facet structure of a round brilliant cut diamond. Here again it is easily in the Top 1% of annual production, but it just goes to show you why I feel that every diamond must be considered on its own merits, regardless of brand name.
Interestingly enough, if you compare the “Hearts and Arrows” images for the 1.224 carat, D-color, VVS-1 clarity, James Allen True Hearts diamond and the 1.208 carat, E-color, Internally Flawless, James Allen True Hearts diamond carefully, you’ll notice that there is no separation between the two halves of the reflections that comprise each heart pictured within the 1.224 carat, the hearts appear as one solid heart… but the hearts shown for the 1.208 carat, appear as two distinct halves; which makes sense since earlier in this article, you learned that each heart is comprised of two halves, which are created by the pavilion main located on the opposite side of the diamond, reflecting off of two lower girdle facets… which means what? Where did the lines go that separate the two halves of each heart? Take your best guess and leave a comment below, I’d love to hear your thoughts on this.
If you’ve got your heart set on buying the finest looking hearts and arrows diamond that I’m seeing at the moment, in the range of 1.20 – 1.49 carats, D-color, and VVS-1 or higher in clarity, then my recommendation is this 1.255 carat, D-color, Internally Flawless, Brian Gavin Signature round ideal cut diamond. As you can see from the photograph featured to the left, this Brian Gavin Signature diamond exhibits a crisp and complete pattern of hearts and arrows, which is consistent in size, shape, and spacing… the diamond exhibits a superior level of optical symmetry, as a result of extremely precise indexing and alignment of the facets, quite literally in all directions, 360 degrees![separator]
The ideal scope image provided for this 1.255 carat, D-color, Internally Flawless, Brian Gavin Signature hearts and arrows diamond is quite literally picture perfect! There is a consistent and even distribution of pink that is visible throughout the diamond, and the diamond is not showing any signs of light leakage from under the table facet. This is exactly how I expect an ideal scope image to look for an ideal cut diamond which is cut to proper proportions, and cut to exhibit the highest volume of light return! This diamond features a crown angle of 35.0 degrees with a crown height of 15.2% which is offset by a pavilion angle of 40.7 degrees and a pavilion depth of 43.0% which is absolutely great![separator]
This diamond is going to exhibit a high volume of light return, with a virtual balance of brilliance and dispersion, and the 76% lower girdle facets are going to produce flashes of light (sparkle) which are bold, bright, and beautiful! It goes without saying that it has an overall cut grade of AGS Ideal-0 and that the ASET image looks absolutely amazing! I don’t know when the last time was that I saw anything close to a 1.255 carat, D-color, Internally Flawless, Hearts and Arrows round diamond, so I hope that you snatch it up before it disappears!
Todd Gray is a professional diamond buyer with 30+ years of trade experience. He loves to teach people how to buy diamonds that exhibit incredible light performance! In addition to writing for Nice Ice, Todd "ghost writes" blogs and educational content for other diamond sites. When Todd isn't chained to a desk, or consulting for the trade, he enjoys Freediving! (that's like scuba diving, but without air tanks)
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