Hi Todd, that is a really useful blog [referencing my post Online Options for UK Diamonds] and I thank you from myself and probably many others. After looking through the James Allen, Blue Nile And Brian Gavin sites, I found several options within my budget of $3,000.00 can you look them over [links below] and give me some insight as to which would be your preferred options? Also, how easy would it be to have a stone set if I ordered it as a loose diamond and either took it to a local jeweler or decided upon the James Allen setting but didn’t want any of their stones? Kind regards and thank once more. You have no idea how useful it is to be able to discuss things with such an experienced and enthusiastic person! — Richard T.
Thanks Richard, I’m so happy that you enjoyed my blog post about buying a diamond from the United Kingdom, and I’m more than happy to help you sift through all of the options… Let’s face it, after 25+ years working as a diamond buyer, it only takes me a few seconds to consider all of the data provided on a diamond grading report, and a diamond details page, and I’m pretty sure that you don’t want to spend the next three weeks trying to become an expert in diamonds.
Note: Blue Nile changed the format of how deep links were created when they switched their affiliate network from GAN to CJ, and thus the original links to the following diamonds were broken and have been replaced with links directed to their diamond search engine, which is fine since these options have probably sold by now. Please use my free Diamond Concierge Service if you would like me to help you find the best options currently available, but the information that can be obtained by reading the article is still applicable even if the diamond details pages can not be accessed.
Pictured to the left is the GCAL diamond grading report for this Blue Nile Signature Diamond weighing 0.54 carats, F-color, VS-2 clarity, which is currently selling for $2,227.00 and is also accompanied by a GIA diamond grading report which indicates that the diamond has an overall cut grade of GIA Excellent. According to the GIA, the diamond measures 5.21 – 5.24 x 3.22 mm and has a total depth of 61.7% with a table diameter of 57% with a crown angle of 35.5° with a pavilion angle of 40.6° and a medium to slightly thick, faceted girdle and no culet.[separator]
The first thing which I noticed is that the proportions of the Blue Nile Signature Diamond described above, does not meet my selection criteria for the proportions of a diamond, which are as follows:
Total depth between 59 – 61.8%
Table diameter between 53 – 57.5% (maybe 58%)
Crown angle between 34.3 – 34.9 degrees
Pavilion angle between 40.6 – 40.9 degrees
Girdle thickness between 0.7% thin to medium, possibly slightly thick
Culet size: GIA “none” or AGS “pointed” (same thing)
Overall Cut Grade: GIA Excellent, or AGS Ideal-0 (preferred)
The inspiration for the range of proportions which I rely upon to select diamonds which exhibit maximum light return, is based upon Tolkowsky’s Diamond Design, which provides the formula for optimizing a diamond for brilliance and dispersion. I relied on this formula when I was the diamond buyer for Nice Ice, to narrow down the list of diamonds which I was considering with the intent of bringing them in for physical evaluation, to improve the odds of finding diamonds which met my expectations for light return, and visual performance, and to cut down on the cost involved with shipping diamonds back and forth.
So while it is quite likely that the Blue Nile Signature Diamond described above, exhibits pretty nice light return, it’s unlikely that I ever would have brought it in for physical evaluation, because I personally don’t like the combination of a 35.5 degree crown angle being offset by a 40.6 degree pavilion angle. I feel that a 35.5° crown angle is too steep, especially when it is combined with the extra height created by a girdle edge which is medium to slightly thick… so this is not my kind of stone, but that’s not to say that it’s not beautiful, it probably is… but I’d hold out for something cut a bit tighter.
This Blue Nile Signature Diamond, weighing 0.54 carats, E-color, VS-1 in clarity, is an option which I like a little bit better… According to the GIA, the diamond measures 5.21 – 5.24 x 3.23 mm and has a total depth of 61.7% with a table diameter of 56% and a crown angle of 34.5 degrees which is offset by a pavilion angle of 41.0 degrees with a medium to slightly thick, faceted girdle and no culet. The diamond has an overall cut grade of GIA Excellent and exhibits medium blue fluorescence.[separator]
Did you happen to notice that the pavilion angle is one tenth of a degree steeper than my preferred range of 40.6 – 40.9 degrees? That’s not so far off, the reality is that the range which I designated represents the ultimate sweet spot in terms of proportions, but there are other combinations of measurements which produce similar levels of light return, and one tenth of a degree is not a deal breaker in my opinion.
I like how this diamond looks on paper, the primary inclusions are just a couple of diamond crystals, and I’m a big fan of medium blue fluorescence, and think that it will make this E-color diamond look absolutely dreamy! This diamond is currently priced at $2,445.00 and I think that it’s a really good option!
This 0.50 carat, VS-2 clarity, D-color, Blue Nile Signature Diamond, is graded by the GIA Laboratory with an overall cut grade of GIA Excellent, and is accompanied by a GIA Diamond Dossier, which does not provide a plotting diagram… so while it tells us that the primary inclusions consist of crystals and feathers, it does not provide us with insight as to the number, location, size, or extent of those inclusions.[separator]
Thankfully the clarity photograph which is provided on the supplementary GCAL diamond grading report, provides us with the clarity photograph that appears above. Now the clarity photograph is not very large, but I have highlighted what I believe to be the feather, with the red arrow which appears in the relative one o’clock position of the upper half of the diamond, which is pictured on the left. The feather doesn’t look too bad, and the diamond crystals don’t seem to be all that noticeable.
According to the GIA, this diamond measures 5.08 – 5.11 x 3.14 mm and has a total depth of 61.7% with a table diameter of 56% and a crown angle of 35.0 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 you know that the 35.0° crown angle is two tenths of a degree steeper than I prefer, but it’s not so bad, because the 40.6° pavilion angle is on the shallower side of my preferred range, so they kind of offset the difference.
This 0.54 carat, VS-2 clarity, D-color, Blue Nile Signature Diamond, is graded by the GIA Laboratory with an overall cut grade of GIA Excellent, and measures 5.29 – 5.33 x 3.23 mm with a total depth of 60.7% and a table diameter of 56% with a crown angle of 34.0 degrees and a pavilion angle of 40.8 degrees with a thin to medium, faceted girdle and no culet. The overall cut grade is GIA Excellent, and the primary inclusions are indicated as being needle shaped diamond crystals and feathers.
All right, this diamond is accompanied by a diamond grading report which is in dossier format, so there isn’t a plotting diagram that is going to provide us with any insight as to the inclusions… that’s something that drives me nuts! And the clarity photograph provided on the GCAL diamond grading report is so small, that I can’t locate or identify the inclusions… and I don’t like not being able to judge the size, extent, or locations of feathers, because a “feather” is a minute fracture, and some are fine, and others are not.
Obviously the crown angle of this diamond is a bit shallower than I prefer, but it’s going to have great light return because of the 40.8° pavilion angle, the crown angle is primarily going to dictate the nature of the light return, not the volume… so if I had to guess, this diamond will exhibit a little more brilliance than fire. It should be a very pretty diamond, which exhibits lots of white sparkle, but not being able to identify the extent of the feather bugs me… so I’m inclined to pass on it, until we have more information (which I can get if it’s really of interest to you).
This 0.55 carat, D-color, VS-2 clarity, Blue Nile Signature Diamond is a WINNER! According to the GIA it measures 5.29 – 5.31 x 3.27 mm with a total depth of 61.7% and a table diameter of 55% with a crown angle of 34.5 degrees offset by a pavilion angle of 40.8 degrees with a thin to medium, faceted girdle and not culet, with an overall cut grade of GIA Excellent. So we finally have an option which actually meets my selection criteria for proportions, polish and symmetry![separator]
Essentially this diamond has been optimized for maximum light return, it’s going to be a bright, white, vibrant looking diamond! The primary inclusions are indicated as being crystals, which most likely are just tiny diamonds that were trapped within the larger diamond crystal as it grew, no big deal, especially in a VS-2 clarity grade diamond.
This 0.57 carat, D-color, VS-2 clarity, Blue Nile Signature Diamond, doesn’t really grab my attention… It’s graded by the GIA with an overall cut grade of Excellent, it measures 5.31 – 5.35 x 3.29 mm with a total depth of 61.7% and a table diameter of 57% with a crown angle of 35.0 degrees and a pavilion angle of 40.8 degrees with a medium to slightly thick, faceted girdle and no culet. By my standards, the crown angle is a little steep, and it’s not a great offset for the 40.8 degree pavilion angle, so this is not a diamond that I would bring in for evaluation, but it’s still cut to the Top 2% of all the round brilliant cut diamonds that are produced in the average year… so it’s a pretty nice stone, it’s just not “Nice Ice” material.
Part of my decision is based upon the variance of the hearts pattern that I see within the pavilion view clarity photograph that is provided on the GCAL diamond grading report, there is also a lot of twisting in the hearts, which is an indicator of azamet shift. Now I haven’t really discussed this with any of the Blue Nile diamonds up to this point, because I don’t expect to find Hearts & Arrows quality diamonds on their web site, but this one seems to exhibit a little more variance than expected, so I’m inclined to pass on it… maybe it’s just because I really like the look of the 0.55 carat, D-color, VS-2 clarity, Blue Nile Signature Diamond that we discussed just before this one.
This 0.61 carat, F-color, VVS-2 clarity, Blue Nile Signature Diamond is another WINNER! It’s graded by the GIA with an overall cut grade of GIA Excellent, and measures 5.47 – 5.51 x 3.35 mm with a total depth of 61.0% and a table diameter of 55% with a crown angle of 34.5 degrees and a pavilion angle of 40.8 degrees with a thin to medium girdle and no culet. And it exhibits medium blue fluorescence, which I happen to be a big fan of. The primary inclusions are indicated as being diamond crystals in the form of pinpoints and needles, nothing to be concerned about. And the hearts look pretty consistent, with very little twisting, so I like the look of this one, it’s definitely a contender!
Now we’re going to take a look at the first diamond which you selected from James Allen, and I have to admit that I’m a little bit confused because everything that we’ve looked at up until now, was in the color range of D-F which is considered to be colorless. But this next diamond is an I-color diamond, so it’s like we just switched gears, there is going to be a distinct visual difference between the tonal value of a D-F color diamond and an I-color diamond, it’s kind of like the difference in tonal value between a sheet of Kodak Photo Paper and a plain white sheet of copy paper… one is not better than the other, it’s a matter of personal preference, it just kind of caught my attention.
This 0.51 carat, I-color, VVS-2 clarity, James Allen True Hearts Diamond is graded by the GIA with an overall cut grade of GIA Excellent. It has a total depth of 61.1% and a table diameter of 57% with a crown angle of 34.5 degrees with a pavilion angle of 40.8 degrees with a thin to medium, faceted girdle and no culet, so it’s cut to the range of proportions that I rely upon to ensure that my clients buy diamonds which have been optimized for maximum light return. The primary inclusions consist of clouds, pinpoints, and indented naturals, none of which are a concern. The diamond exhibits a very good pattern of Hearts & Arrows, with minor variations in size and shape.[separator]
This diamond is definitely a contender, it’s going to exhibit great light return and a lot of sparkle! The only concern that I have with this diamond is the color, but only because everything else that you’ve looked at up to this point was D-E-F color.
This 0.506 carat, F-color, VS-2 clarity, James Allen True Hearts Diamond is more in line with the other options which you asked me to consider, it’s back up in the colorless range. One of the things which I really like about this diamond is that it’s graded by the AGS Laboratory on their Platinum Light Performance grading platform, with an overall cut grade of AGS Ideal-0, which is the highest rating available. One of the advantages is that this report provides us with an image of the diamond showing the results of the Angular Spectrum Evaluation Tool analysis, which is the red, blue, and green image located in the center of the lab report pictured to the left. The combination of the ASET image and the Hearts & Arrows image provided on the diamond details page, enables me to judge the optical symmetry of the diamond, this is going to be a very vibrant and sparkly diamond![separator]
According to the AGSL, the diamond measures 5.08 – 5.11 x 3.15 mm and has a total depth of 61.9% which is just a hint deeper than my preferred range of 59.0 – 61.8% and not enough to disqualify the diamond; it has a table diameter of 57.2% and a crown angle of 34.4 degrees which is offset by a pavilion angle of 40.9 degrees with a thin to slightly thick, faceted girdle and a pointed culet, which is all good.
My only concern, is that if you look at the feathers indicated in the eleven o’clock and relative 2:30 positions on the upper plotting diagram presented on the AGS Diamond Quality Document (DQD) they look kind of ominous, clustered together, stacked on top of one another, it kind of makes me itch… yet at the same time, I don’t see them plotted on the underside of the diamond, so they’re not running through the stone, it’s one of those things which I tend to avoid as a diamond buyer, but which probably has no effect upon the durability of the diamond… it’s one of those “mind clean” things.
This 0.522 carat, E-color, VVS-2 clarity, James Allen True Hearts Diamond is an excellent option! It is graded on the AGSL Platinum Light Performance grading platform with an overall cut grade of AGS Ideal-0 and it exhibits a really nice pattern of hearts and arrows! According to the AGSL, the diamond measures 5.16 – 5.19 x 3.19 mm with a total depth of 61.6% and a table diameter of 56.7% with a crown angle of 34.7 degrees which is offset by a pavilion angle of 41.0 degrees and a thin to medium, faceted girdle and a pointed culet. So you probably noticed that the pavilion angle is one tenth of a degree steeper than my preference, we discussed this concept previously and it still applies.[separator]
According to the AGSL, the primary inclusions consist of pinpoint size diamond crystals and feathers, and it is these inclusions that are disrupting the hearts pattern in the photograph above… this is not a bad thing, I’m just explaining what is affecting the hearts pattern because people tend to wonder about this. The reason the inclusions are visible in this photograph is that the scope which enables us to view the hearts and arrows pattern of a diamond, incorporates a 3x magnifying lens.
The last diamond which you asked me to look at Richard, is this 0.61 carat, D-color, VS-1 clarity, James Allen True Hearts Diamond, and it has a crown angle of 35.0 degrees which is offset by a pavilion angle of 40.8 degrees, which we know is not my favorite, but it’s not bad either. The diamond has a total depth of 61.2% and a table diameter of 56% with a thin to medium, girdle edge and no culet, with an overall cut grade of GIA Excellent. The pattern of hearts and arrows looks pretty good, it’s not perfect, but it’s not terribly imperfect either.
Since you mentioned Brian Gavin in your initial inquiry, I decided to poke around his web site a bit and see what might be available, because I’m truly partial to the overall cut quality and the visual performance which results… Here’s what I found:
This 0.522 carat, F-color, VS-1 clarity, Brian Gavin Signature Diamond is an excellent option that meets my selection criteria, for all factors including the overall cut grade, and the optical symmetry of the diamond, which has a direct affect upon the light return and sparkle factor of the diamond. It exhibits a crisp and complete pattern of Hearts & Arrows, looks great when viewed through an ASET Scope, looks great through an Ideal Scope, and fits within your desired price range!
According to the AGSL, the diamond measures 5.16 – 5.18 x 3.17 mm and has a total depth of 61.4% and a table diameter of 57.7% and a crown angle of 34.9 degrees with a pavilion angle of 40.8 degrees with a thin to medium, faceted girdle and a pointed culet. The primary inclusions are small crystals, needles, feathers and pinpoints.
This 0.534 carat, E-color, VS-1 clarity, Brian Gavin Signature Diamond is as equally impressive! It has an overall cut grade of AGS Ideal-0, exhibits a crisp and complete pattern of hearts and arrows, and looks great when viewed through an ASET and Ideal scope. According to the AGSL, it measures 5.21 – 5.23 x 3.22 mm with a total depth of 61.6% and a table diameter of 55% with a crown angle of 34.9 degrees which is offset by a pavilion angle of 40.7 degrees with a thin to medium, faceted girdle and a pointed culet. The primary inclusions are just a few diamond crystals, nothing to worry about. This diamond also fits within your price range.
All right, we’ve run through all of the characteristics, discussed the effect that the proportions have upon the light return of the diamond and talked a little bit about the importance of optical symmetry as it applies to the sparkle factor of a diamond. With that in mind, if I were buying a diamond for myself, I’d most likely buy one of the Hearts & Arrows options from Brian Gavin, simply because I know that a precise pattern of hearts and arrows, combined with tight proportions, and an overall cut grade of AGS Ideal-0, produces a vibrant looking diamond which exhibits lots of light return and incredible sparkle!
Very few of the options from Blue Nile are truly tempting to me, primarily because I know that the diamonds lack the optical symmetry that is provided by the Brian Gavin and James Allen options, here again, I feel that the presence of a crisp and complete pattern of Hearts & Arrows is a critical factor to the visual performance of a round brilliant cut diamond. For one thing, the crisp arrows pattern will create contrast in the diamond, and contrast enables our eyes to better see the beauty of a diamond, or at least I like a diamond with a lot of contrast in it, and you may prefer a diamond with less contrast… it’s all a matter of personal preference. But of all the options available from Blue Nile, I like these the best:
The options which I find of interest from James Allen are the 0.51 carat, I-color, VVS-2 clarity, James Allen True Hearts Diamond, but I’m concerned that the color is going to be a bit warmer than you want, simply because every other diamond which you asked about is higher in color. I also like the look of the 0.522 carat, E-color, VVS-2 clarity, James Allen True Hearts Diamond
I hope that you find this evaluation to be as helpful as the first one which I wrote for you Richard, and by all means, invite you to continue to ask any questions which pop into your head as you go through the diamond selection process… I think you’ll find that some retail jewelry stores are willing to set diamonds which were not purchased from them, especially if you’re buying a setting from them, but other jewelry stores will not be willing to assume the liability that goes with setting a diamond. So you’ll need to ask around and find a jeweler who is willing to take on the project, and if you’re intent on one of the Brian Gavin Diamonds, I’d recommend sending them an email with links to the settings which you shared with me and ask them if they offer anything similar.
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