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Help choosing between round brilliants!


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Hello, I've made a deep dive into trying to figure out the diamond world but I'm still quite a bit overwhelmed. Here's what I'm looking for:

- Carat: 2.5 - 3 carat

- Cut: Ideally Ideal

- Color: D - I 

- Clarity: SI1 + 

Budget: $18,500 - Lab grown stones

I've been going off of random internet guides, and following generally this advice:

Recommended Diamond sizing

  • Table Percentage: 55 – 57%
  • Total Depth:

    • 60 – 61.5% (for girdle thickness between 2.5 – 3.5%)
    • 61.5 – 62.5% (for girdle thickness between 3.5% – 4%)
  • Crown Angle (CA)/ Pavilion Angle (PA)
    • For CA = 34°, PA = 41°

    • CA = 34.5°, PA = 40.6° – 40.8°

    • 35°, PA = 40.6°
  • Star Length: 50 - 55%
Lower Girdle Length: 75 – 80%

  • Girdle Thickness: Thin to medium (2.5 – 3% preferred)


And here are my options:


The number underneath is the price! Please try to ignore the strange color coding, I'm working on a fun side project to try and give each stone a score based on some of their statistics. It's not quite there yet, and very limited on how I'm calculating so I've hidden the scores.

Please let me know if you'd like videos of the stones, it's not letting me attach the videos I have currently but I will try in the next post.

Another issue I'm dealing with is that these lab-grown are from 3 different vendors, with 3 different types of upgrade programs, so there's a few other factors I'm keeping in mind, so a 1 or 2 top choices would be extremely helpful!

I'm in the process of requesting ASET for some of these, here's the ASET for the 2.73 Super Ideal G VS1:


ASET - 2-73.jpg

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The good news: on paper, all the six look very good. Take your pick.

The bad news: you are trusting the vendor that these are actually anything like the colour (and to some extent clarity) they say they are. Similarly for cut: are the measurements accurate? Probably yes (a Sarine scanner will take them accurately, if it's set up and operated properly), but I only have the dealer's word for it, not a third party's.

For example, I may be wrong, but I don't think it's possible to grow synthetic diamonds of that size in that colour - if we use the same definition of colour as GIA does. This issue is compounded when you are not dealing with one vendor but 3 - each will use its own standards.

Another issue - though that would apply to any stones, synthetic or natural - is that all of them are cut very well on paper, but we know relatively little about their real cut quality (averages of angles are good, but what's the deviation from the average?). For example, that ASET image is tilted or the diamond is wonky - which is it? (More likely the former than the latter, but...). The more information you can get on cut, and the more you are protected by a return period in which the vendor will refund 100% of your money, the better!

TL, DR: they all look good on paper; if you trust the paper, take your pick. I don't trust those papers because I'm dealing with unknown people.

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You’re assuming some facts not in evidence here.  For example, the difference between ‘ideal’ and ‘super ideal’.  Neither term is well defined and different dealers do not use the same standards. In the case of synthetics, color and clarity fall in this category as well. The graders don’t all use the same scales and they don’t all apply the scales in the same ways.

#1 Know who the labs are and have an opinion.  Personally, I like GCAL and IGI Hong Kong, in that order, but there are a lot to choose from and they are not all the same.

#2 Know and understand claims like idealness and that ASET image (It almost certainly did NOT come from the lab, which begs the question of where it did come from. As with the above, there are many different ways of taking these photos and they are not directly comparable.)

#3 Know your sources. That’s decent generic advice for shopping round brilliants, either mined or synthetic, but the internet is full of nonsense. Assign credibility to your sources, be aware of hidden agendas and ignore the charlatans.  Including us by the way.  The fact that we’re handing out free advice on the internet is a mark against, not in favor.  I’m happy to provide my agenda (this is advertising for me). Apply this standard to all of your sources. Relying on random internet guides is trouble. 

As mentioned by Davide, that ASET is either a bad example of a 'super ideal', a bad image, or possibly both. 

Edited by denverappraiser
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Thank you both so much for your input!

I want to clarify that all of the statistics are from IGI reports, not just the word of the vendor, though I am aware that IGI ratings can vary from where the diamond was evaluated. For example, some have "Ideal" in the cut, and some say "Cut: Excellent" and then write Ideal in the comments. The "Super Ideal" rating is from BrilliantEarth, as they have their own qualifications on what makes a lab diamond super ideal, even though the IGI report doesn't reflect it. I'm definitely aware of that as well but I still wanted to document that BE signified a difference in that particular diamond, even though it doesn't sway me much over the other Ideals.

All of the vendors are reputable, online sellers, I definitely appreciate the advice to be wary though. One has offered to bring 2 diamonds in and do a video call to compare, but may not be able to provide ASET which is worrisome. (waiting to hear back), the other has been very responsive and provides ASET/Video/etc.

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ASET is unusual. That's an AGS thing. AGS is unusual, and AGS lab doesn't grade synthetics at all. Certain individual dealers like it, and I like it, but there are plenty who have never even heard of it, much less are practiced enough to take good pictures. It's a whole art form.  The same holds for videos. I like them, and I'm all for asking, but it's a lot harder to do that than it looks and most dealers aren't prepared.  

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I've been trolling the lab grown world for a few years now and it is surprising that the vast majority of lab grow cutters do not cut for ideal make.  It does not make a lot of sense to me as their raw material is much more affordable and the weight loss should not be as big an issue.  I'm impressed you were able to find so many very decently cut stones. 


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