Hi Todd, a friend of mine recommended your diamond concierge service after you helped him buy a pair of diamond earrings for a Christmas present. I’m in the market for a diamond engagement ring and am trying to decide between several diamonds which I found on James Allen and Ritani. I noticed that each vendor seems to have their own classification of ideal cut diamond, which I assume to be the best they have to offer, so I limited my search to Ritani Reserve Ideal and James Allen True Hearts, 1.0 – 1.2 carats, H color, VS2 clarity, with an overall cut grade of AGS Ideal which you seem to prefer over GIA Excellent. Can you help me select the best option? Thanks! — David P.
Thank you for your inquiry. Of the four diamonds which you presented me with David, the hands-down winner is the 1.148 carat, H-color, VS-2 clarity, James Allen True Hearts diamond for which the hearts pattern is pictured to the left and the clarity photograph is featured at the top of this page. Quite simply this diamond has the best overall proportions of the group and the hearts and arrows pattern indicates that it likely has a higher degree of optical symmetry than the options which you suggested from the Ritani Reserve Ideal Cut Diamonds collection. I only wish that the Diamond Quality Document issued by the AGSL featured an ASET image of the diamond.
The term “ASET” is an abbreviation for Angular Spectrum Evaluation Technology which is proprietary to the American Gem Society Laboratory (AGSL) and provides insight into the different levels of brightness created by the combination of proportions and the optical symmetry of the diamond. ASET provides an insight which is invaluable to the diamond selection process as you will see by what is revealed in the Reviews of Ritani Reserve Ideal cut diamonds provided below. I don’t know why James Allen would decide not to opt for the AGSL report format which features an ASET image for a diamond which scored zero for light performance, but I wish they had ordered that version of the report for this diamond.
Working with the information that is available on this diamond, we know that the diamond has an overall cut grade of AGS Ideal-0 and that it scored zero for light performance, polish, symmetry and proportions, as indicated in the upper right corner of the flap featured on the diamond grading report. The diamond has a total depth of 61.6% and a table diameter of 56.2% with a crown angle of 34.9 degrees that is offset by a pavilion angle of 40.9 degrees with a thin to medium, faceted girdle and a pointed culet.
This particular range of proportions is recognized as being the center or “sweet spot” and is well known for producing diamonds which exhibit a high volume of light return. My guess is that this diamond will face up nice and bright and exhibit the full spectrum of sparkle that you’re probably hoping for… the primary inclusions consist of diamond crystals and groups of pinpoints size diamond crystals called clouds.
The first thing which I noticed about this 1.041 carat, H-color, VS-2 clarity, Ritani Reserve Ideal cut diamond is that the pavilion mains are pretty narrow. This is evident if you look at the blue arrows pattern visible within the ASET image provided on the AGSL Light Performance diamond grading report pictured to the left. Since an ASET image is provided for this diamond, it is also possible for us to determine that there is a bit of inconsistency in terms of the distribution of brightness along the outer edges of the diamond as indicated by the inconsistent patterning of red and green. There tend to be two lines of thinking regarding this type of thing, one camp says “Hey the diamond scored zero for light performance” and the other camp says “Yea but I’d prefer a pattern of brightness which indicates that the distribution of brightness be more even” and you can guess which one I fall into.
In addition to not being thrilled with the look of the ASET image for this Ritani Reserve ideal cut diamond, I think that a pavilion angle of 41.2 degrees is too steep and results in a lesser volume of light return than is provided by my preferred range which is between 40.6 – 40.9 degrees, as stated within the article 15 Seconds to Diamond Buying Success.
Combine the slightly steep pavilion angle of 41.2 degrees with the larger table diameter of 59.9% and the reality is that this diamond is sitting right on the outer edge of the parameters for the zero ideal cut proportions rating and I think that you could do better.
Things look a little better in terms of the consistency of the pattern of light return and brightness exhibited by this 1.143 carat, H-color, VS-2 clarity, Ritani Reserve Ideal cut diamond, but the pavilion mains still look kind of spindly and I’m not overly thrilled with the 33.9 degree crown angle, although it’s not a horribly bad offset for the 41.0 degree pavilion angle. What really kills the stone for me however is the cavity indicated on the lower plotting diagram of the lab report just below the three o’clock position.
A cavity is exactly what it sounds like, a small hole located in the surface of the diamond and if you look really close you’ll see that this one also has a feather extending out from it, which is a small fracture and since this is located along the girdle edge of the diamond, this diamond does not meet my selection criteria for proportions or inclusions despite the overall cut grade of AGS Ideal-0.
This Ritani Reserve Ideal cut diamond is so far off the mark in my opinion that I don’t even know where to begin… but since a picture is worth a thousand words, let’s start with the ASET image which I interpret as indicating that the pavilion main facets did not exhibit any contrast during the scan because they are completely missing from the image!
I’m guessing that this is due to the fact that the pavilion angle is extremely steep at 41.5 degrees, but it might actually work well with the crown angle which is very shallow at 33.7 degrees. Generally speaking, you either want everything in the middle of the range, or you want to combine steep with shallow or vice versa, but the measurements of this diamond actually hurt my head! And just look at how inconsistent the pattern of light return appears within the ASET scan… forget about it. What can I say, not all ideal cut diamonds are created equal.
Take a second to look at how the pavilion main facets represented by the arrows pattern which is visible within the James Allen True Hearts diamond pictured at the top of this page, that is how I expect the pavilion main facets to look in terms of thickness. Then take a look at the pavilion main facets appear in the ASET images featured on the diamond grading reports for the Ritani Reserve Ideal cut diamonds… do you see how narrow and thin-looking they are? In this particular instance, I’m definitely leaning towards the 1.148 carat, H-color, VS-2 clarity, James Allen True Hearts diamond because I feel that it is going to deliver a higher volume of light return and provide the contrast that I expect from a diamond of this cut quality, but I’d still like to see an ASET image for the diamond just to be sure.
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)
AGS Laboratory Introduces Advanced ASET for Light Performance
Win a $10K Diamond Ring from James Allen
French Set Halo Ritani vs Brian Gavin Anita in 2019 (which Sparkles more)
Costco Diamonds Versus Blue Nile – Which Sparkle More (and Why?)
Are Twinning Wisps in Diamond Good or Bad? (Alarming Insight)
James Allen vs Brian Gavin Diamonds (Updated 2019)
Is K Color Diamond Too Yellow? (Secret Ways to Save BIG)
One carat diamond buying guide (tips and tricks to save big)