Hi Todd, I am considering some 6 diamonds and I need some help narrowing down my choices. Could you help? Here are my choices: (1) 1.298 carat, D-color, VS-2 clarity, Brian Gavin Signature Round; (2) 1.308 carat, F-color, VS-1 clarity, Brian Gavin Signature Round; (3) 1.310 carat, E-color, VS-2 clarity, Brian Gavin Signature Round Diamond; (4) 1.41 carat, D-color, VS-2 clarity, James Allen True Hearts diamond; (5) 1.43 carat, F-color, VS-2 clarity, James Allen True Hearts diamond; (6) 1.507 carat, G-color, VS-2 clarity, Brian Gavin Blue diamond. Thanks! K.
The 1.298 carat, D-color, VS-2 clarity, Brian Gavin Signature Round with Hearts & Arrows pattern, is graded by the American Gem Society Laboratory (AGSL) with an overall cut grade of AGS Ideal-0, which is the highest rating available, and which takes Light Performance into account. The AGSL is the only top tier laboratory which employs the use of an Angular Spectrum Evaluation Tool as part of their evaluation process, it is designed to determine how the diamond is making use of the light which is available to it within the room, and demonstrate how it is reflecting that light back up towards the viewer (that’s you). The picture to the left is the ASET image for this diamond.[separator]
According to the AGSL, this diamond measures 6.99 – 7.00 x 4.32 mm, so it’s nice and round, practically perfectly round, and it has a total depth of 61.8% with a table diameter of 57% and a crown angle of 34.6 degrees which is offset by a pavilion angle of 40.9 degrees with a thin to medium, faceted girdle, so it is cut to the center range of the spectrum for the zero ideal cut proportions rating, and optimized for maximum light return, in accordance with Tolkowsky’s Diamond Design.
The diamond exhibits a crisp and complete pattern of Hearts & Arrows, which is a clear indication that the diamond exhibits exceptional optical symmetry, because the pattern only results when the facet sections of the diamond are consistently shaped, and precisely aligned three dimensionally across the diamond horizontally and vertically. Top level optical symmetry such as this, results in a higher number of virtual facets, larger flashes of light, and more sparkle.
The inclusions are indicated on the plotting diagram which appears on the AGSL Diamond Quality Document (DQD) as being crystals, a feather, and needle shaped diamond crystals. The feather is located deep within the pavilion (lower half) of the diamond, where it poses no issue, and the diamond crystals appear to mostly be located within the table facet, and they are difficult to locate using the magnification tool provided with the clarity photograph that is available on the diamond details page. This is definitely a diamond which I would choose for myself…
The next diamond that we’re going to consider is this 1.308 carat, F-color, VS-1 clarity, Brian Gavin Signature Round with Hearts & Arrows pattern, which is also graded by the AGSL with an overall cut grade of AGS Ideal-0 as determined on the Platinum Light Performance grading platform. According to the AGSL, this diamond measures 6.99 – 7.04 x 4.34 mm and has a total depth of 61.9% and a table diameter of 57% with a 34.9 degree crown angle which is offset by a pavilion angle of 40.9 degrees with a thin to medium, faceted girdle and a pointed culet. The primary inclusions are diamond crystals, and small groups of pinpoint size diamond crystals which are known as clouds, these are just tiny diamond crystals that were trapped within the larger diamond crystal as it formed, and as such, they are of no concern.[separator]
This is a photograph of the hearts pattern which is visible within this 1.310 carat, E-color, VS-2 clarity, Brian Gavin Signature Round Diamond, when it is viewed while unmounted through a Hearts & Arrows viewer. The pattern of hearts is crisp and complete, and evenly spaced, which is an indication of the superior optical symmetry of this diamond. This diamond is also graded by the AGSL with an overall cut grade of AGS Ideal-0, and has a total depth of 62.0% with a table diameter of 55.1% and a crown angle of 34.2 degrees with a pavilion angle of 40.9 degrees and a thin to medium, faceted girdle with a pointed culet. The combination of proportions and optical symmetry should produce incredible sparkle![separator]
According to the AGSL, the primary inclusions consist of diamond crystals, feathers, and needle shaped diamond crystals, all of the feathers appear to be located well within the body of the diamond, and as such, I consider them to be benign and of no consequence.
This 1.41 carat, D-color, VS-2 clarity, James Allen True Hearts diamond is a pretty rare find in terms of carat weight, there are very few ideal cut diamonds produced within the range of 1.40 – 1.49 carats, because the cutter would have been better off from a financial perspective to produce a lesser quality cut diamond which weighed more than 1.50 carats, because of the price increase which occurs between the 1.49 – 1.50 carat marks. With that in mind, there is a bit more variation in the hearts pattern than I would like to see, the biggest variation being the bending of the tip of the heart located in the nine o’clock position of the photograph to the left, as indicated by the yellow arrow.[separator]
This diamond is graded by the Gemological Institute of America (GIA) with an overall cut grade of GIA Excellent, which is the highest cut grade available from the GIA, which does not use the Angular Spectrum Evaluation Tool (ASET) as part of their evaluation process. According to the GIA, the diamond measures 7.14 – 7.17 x 4.47 mm with a total depth of 62.4% and a table diameter of 56% with a crown angle of 36.0 degrees which is offset by a pavilion angle of 40.6 degrees with a medium to slightly thick, faceted girdle and no culet.
All right, so I truly prefer to see the total depth of a round brilliant cut diamond be somewhere between 59 – 61.8% with a table diameter between 53 – 58% and a crown angle between 34.3 – 34.9 degrees, offset by a pavilion angle between 40.6 – 40.9 degrees, with a thin to medium, polished or faceted girdle, and a culet of either GIA “none” or AGS “pointed” which is the same thing…
So the total depth of this diamond is a bit deep for my personal preference at 62.4% as a result of the steep 36.0 degree crown angle and the medium to slightly thick girdle, but I’ve seen this crown angle work well with a 40.6 degree pavilion angle in the past… Realize that my selection criteria is designed to quickly narrow down the available options, but there are other combinations which produce similar volume of light return, and this is one of them.
Likewise, the total depth of the 1.308 carat, F-color, VS-1 clarity, Brian Gavin Signature Diamond referenced above is 0.01% deeper than I prefer, but it isn’t likely to have any impact upon the visual properties of the diamond because the volume of light return is primarily dictated by the offset for crown and pavilion angle which are perfect in this case. The effect of a little more total depth than I prefer, might be that the diamond faces up a little smaller in terms of the visible outside diameter, if the diamond were compared side-by-side another diamond with equivalent crown angle, pavilion angle, and girdle thickness, which happens to have a shallower total depth.
The same principle holds true for the 1.310 carat, E-color, VS-2 clarity, Brian Gavin Signature Round Diamond referenced above, which has a total depth of 62.0% which is 0.02% deeper than my personal preference, but which has a crown angle of 34.2 degrees which is offset by a 40.9 degree pavilion angle, the effect of the tenth of a degree variance in crown angle off of my preferred range is not going to be something we’ll ever be able to detect with our human eyes, and thus the difference is negligible.
Getting back to the 1.41 carat, D-color, VS-2 clarity, James Allen True Hearts diamond, the primary inclusions are indicated as being needle shaped diamond crystals, diamond crystals, and an indented natural. The diamond crystals are readily visible in the clarity photograph, which is not surprising since the size of the diamond has been blown up to the size of a tennis ball, but they all appear to be rather clear in appearance. An indented natural is merely part of the original “skin” of the diamond, which indents into the surface of the diamond, it is most likely located along the girdle edge of the diamond, and is not something which concerns me.
This is a screenshot of the video for this 1.43 carat, F-color, VS-2 clarity, James Allen True Hearts diamond, captured while the diamond was being rotated, to point out the primary inclusion which is the diamond crystal indicated at the tip of the red arrow. The diamond crystal appears to be darker in tone, and will most likely be readily and immediately visible through magnification, which is typical of the VS-2 clarity grade. Some people prefer that diamond crystals be more translucent, I don’t care as long as they are not visible to me without magnification, obviously the more translucent a diamond crystal is, the more difficult it will be to see it.[separator]
This diamond is graded by the GIA with an overall cut grade of GIA Excellent, according to the GIA, the diamond measures 7.19 – 7.21 x 4.48 mm and has a total depth of 62.2% with a table diameter of 56% and a crown angle of 34.5 degrees which is offset by a pavilion angle of 40.8 degrees with a medium to slightly thick, faceted girdle and no culet. So by now you realize that the total depth of 62.2% is 0.4% deeper than I prefer, but the good news is that the little bit of extra depth is a result of the slightly thick girdle thickness, and it isn’t going to have any real effect on the volume of light return, because the 34.5 degree crown angle is a perfect offset for the 40.8 degree pavilion angle, so it’s all good.
Last but not least, we have this 1.507 carat, G-color, VS-2 clarity, Brian Gavin Blue diamond which exhibits medium blue fluorescence, and which has an overall cut grade of AGS Ideal-0. I happen to know that the diamonds from the Brian Gavin Blue collection are produced on the same production line as his Signature diamonds, so the optical symmetry and resulting sparkle factor is going to be comparable. The photograph featured to the left, shows the medium blue fluorescence within this diamond as seen in a pitch black room, under the controlled light of a GIA Diamond Light. Most of my personal diamonds have exhibited medium to strong blue fluorescence, I’m quite fond of it.[separator]
According to the AGSL, this diamond measures 7.33 – 7.35 x 4.54 mm and has a total depth of 61.8% with a table diameter of 56.9% and a crown angle of 34.9 degrees which is offset by a pavilion angle of 40.8 degrees with a thin to medium, faceted girdle and a pointed culet.
The primary inclusions consist of several diamond crystals which are scattered about throughout the diamond, I’ve looked at them in the clarity photograph provided on the diamond details page, and in the video which shows the diamond while in rotation, and the diamond crystals appear to be translucent. By the way, if you click on the four white arrows located in the upper right corner of the video provided for this diamond, it will provide you with a larger size video, which makes it easier to see the inclusions.
All right, now that I’ve had a chance to look over all of the characteristics for the six diamonds which you asked me about, the two which really catch my interest are the 1.298 carat, D-color, VS-2 clarity, Brian Gavin Signature Round and the 1.507 carat, G-color, VS-2 clarity, Brian Gavin Blue diamond with medium blue fluorescence, because both of them meet my very strict selection criteria in terms of absolute center range zero ideal cut proportions… the other options are “close enough” but when selecting a diamond for myself, I truly tend to hold out for perfection.
I also like the fact that both diamonds are graded by the AGSL on the Platinum Light Performance grading platform, because the ASET images tell me a lot about how the diamonds are making use of the light which is available to them. In addition, the ideal scope images provide me with a clear indication as to the degree of light leakage, and I am pleased with the type, extent, and location of the inclusions.
Both diamonds are priced within a couple of hundred dollars of each other, so the primary difference between the two diamonds is the body color and a slight difference in carat weight, and the deciding factor as to which to go with is truly a matter of personal preference. Personally, I am inclined to choose the 1.507 carat, G-color, VS-2 clarity, Brian Gavin Blue diamond with medium blue fluorescence, because I think that my girlfriend would prefer the slightly larger carat weight, which is something that she and her girlfriends are more likely to see than a slight difference in body color.
But some people definitely prefer diamonds which are crisp, clean, white, in the cooler tones of D-E-F color, in which case, you might want to go with the 1.298 carat, D-color, VS-2 clarity, Brian Gavin Signature Round.
Note that you did an excellent job of selecting the diamonds which you asked me to evaluate, the reality is that all of them are within the Top 1% of annual production in terms of cut precision and optical symmetry… thus the truth is that any of them is an excellent choice, and the odds are that if we were comparing them side-by-side that the differences between them in terms of the overall volume of light return and sparkle factor would be extremely slight, but the two which I’ve selected are the best of the best, and thus they are the two that I would choose between.
If neither of those diamonds were available, then any of the others would do, but again, I would drill down the characteristics to select the best one of the options available. I hope that you find this evaluation to be helpful, feel free to contact me if you have additional thoughts or questions.
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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