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Crown & pavilion question

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
I’m looking at diamond with 34.9 crown angle and 40.8 pavilion angle. Can anyone tell me if those go together well? TIA for your help.
 

DejaWiz

Shiny_Rock
Joined
Apr 23, 2021
Messages
143
Typically, yes. A 40.8 PA usually pairs well with a CA between 34-35.

Any other info that you have?
- crown height percentage
- overall depth percentage
- table width percentage
- lower girdle facet percentage
- star Facet percentage
- girdle thickness


PA and CA range chart.jpg
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
I’m looking at diamond with 34.9 crown angle and 40.8 pavilion angle. Can anyone tell me if those go together well? TIA for your help.

A crown of 34.9 tells me this isn't a GIA stone. Is it AGS or IGI? If AGS, there may be a ray-traced ASET on the lab report that helps provide confirmation of light return.

The GIA equivalent is 35/40.8 and due to GIA gross rounding I've found those stones to be hit & miss. Some great and some with leakage. So I always consider it a "maybe" until I know more.

A final note: a diamond is not defined by 1 or 2 proportions, but rather all the various proportions working in harmony with each other.
 

Double E

Shiny_Rock
Joined
Jun 23, 2018
Messages
317
You've already got great tips here & would love to know more info. about your target stone :)

That said, I've got my wife a 34.9/40.8 from BGD, looks really great!
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
You've already got great tips here & would love to know more info. about your target stone :)

That said, I've got my wife a 34.9/40.8 from BGD, looks really great!

Your wife’s BGD stone is a good example of why the details matter. More precise AGS lab report without GIA gross rounding to consider, true H&A symmetrical alignment of the facets and a very experienced cutter with full array of advanced images to prove your stone is a performer.

Very risk free and beautiful.
 

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
Typically, yes. A 40.8 PA usually pairs well with a CA between 34-35.

Any other info that you have?
- crown height percentage
- overall depth percentage
- table width percentage
- lower girdle facet percentage
- star Facet percentage
- girdle thickness


PA and CA range chart.jpg

Thank you for all of the helpful feedback! Here’s more info on the diamond:
Crown percentage: 15.1
Depth: 61.9
Table: 56.6
Lower girdle percentage: 76.0
Star percentage: 50.0
I don’t see girdle thickness listed. Should I call for that info?
Thank you!
 

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
A crown of 34.9 tells me this isn't a GIA stone. Is it AGS or IGI? If AGS, there may be a ray-traced ASET on the lab report that helps provide confirmation of light return.

The GIA equivalent is 35/40.8 and due to GIA gross rounding I've found those stones to be hit & miss. Some great and some with leakage. So I always consider it a "maybe" until I know more.

A final note: a diamond is not defined by 1 or 2 proportions, but rather all the various proportions working in harmony with each other.

Thank you for the great info! Yes, it’s an AGS stone. Is it generally preferable to go with aGIA stone? I posted more details on this diamond above & welcome any additional feedback. I don’t see ray-traced ASET on the report. Should I call for that. I’ve been scouring thus forum but am still a total newbie! TIA.
 

DejaWiz

Shiny_Rock
Joined
Apr 23, 2021
Messages
143
Thank you for all of the helpful feedback! Here’s more info on the diamond:
Crown percentage: 15.1
Depth: 61.9
Table: 56.6
Lower girdle percentage: 76.0
Star percentage: 50.0
I don’t see girdle thickness listed. Should I call for that info?
Thank you!


All proportions look great!

Everything lands within super ideal ranges, which is usually regarded as even better than GIA 3x or AGS 000 criteria and constraints.

As long as the girdle thickness is listed as thin, medium, or slightly thick, then it's good to go.

Have you been able to put your own eyes on this particular diamond, yet?
 

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
You've already got great tips here & would love to know more info. about your target stone :)

That said, I've got my wife a 34.9/40.8 from BGD, looks really great!

Thank you and happy you found a great stone! This site is like diamond college:)
 

lovedogs

Super_Ideal_Rock
Premium
Joined
Jul 31, 2014
Messages
13,229
Thank you for the great info! Yes, it’s an AGS stone. Is it generally preferable to go with aGIA stone? I posted more details on this diamond above & welcome any additional feedback. I don’t see ray-traced ASET on the report. Should I call for that. I’ve been scouring thus forum but am still a total newbie! TIA.

Do you have the AGS report? Can you post it? Maybe its an older one without the ray tracing.
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
Thank you for the great info! Yes, it’s an AGS stone. Is it generally preferable to go with aGIA stone? I posted more details on this diamond above & welcome any additional feedback. I don’t see ray-traced ASET on the report. Should I call for that. I’ve been scouring thus forum but am still a total newbie! TIA.

For the best cut quality, AGS is preferred. Multiple reasons that I explained in this response recently.

Can you post a copy of the AGS lab report for us to review?

Below is a sample showing where to find the ray-traced ASET and also where to find the girdle information. Most importantly, we are looking to see what the cut grade, light performance, polish & symmetry is shown on the reports.

With AGS, the best is 0, or ideal. So in the example below all values are 0. Despite having 4 values, we frequently call this an AGS000 report indicating it has received top marks from AGS. Given the proportions you have shared I expect at a 000.

Lastly, I am curious if you are looking at an older lab report. In the upper right corner there should be a date. What does it read?

InkedInkedInkedPGR_2020-sample_LI.jpg
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
Everything lands within super ideal ranges, which is usually regarded as even better than GIA 3x or AGS 000 criteria and constraints.

What are you considering "super ideal range"? My understanding of a super ideal is:
  • AGS000 report
  • True H&A symmetry
  • Advanced images (ASET, IS & H&A) to prove performance
  • Usually branded (ACA, Signature, CBI, etc) but not always
I agree the proportions shared looked very good and would make it a candidate to possibly be a super ideal. However, we do not yet have images to confirm cut precision and/or light performance.

Having good proportions doesn't guarantee a H&A stone.
 

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
All proportions look great!

Everything lands within super ideal ranges, which is usually regarded as even better than GIA 3x or AGS 000 criteria and constraints.

As long as the girdle thickness is listed as thin, medium, or slightly thick, then it's good to go.

Have you been able to put your own eyes on this particular diamond, yet?

Girdle is thin to slightly thick. I haven’t seen it in person, but there are images online. I don’t know how to interpret them, though.
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
Girdle is thin to slightly thick. I haven’t seen it in person, but there are images online. I don’t know how to interpret them, though.

Thin to slightly thick is good.

First off, ask the vendor to place a temporary reserve on the stone you are considering. Once reserved, please share a web link so we can help you further analyze.
 

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
For the best cut quality, AGS is preferred. Multiple reasons that I explained in this response recently.

Can you post a copy of the AGS lab report for us to review?

Below is a sample showing where to find the ray-traced ASET and also where to find the girdle information. Most importantly, we are looking to see what the cut grade, light performance, polish & symmetry is shown on the reports.

With AGS, the best is 0, or ideal. So in the example below all values are 0. Despite having 4 values, we frequently call this an AGS000 report indicating it has received top marks from AGS. Given the proportions you have shared I expect at a 000.

Lastly, I am curious if you are looking at an older lab report. In the upper right corner there should be a date. What does it read?

InkedInkedInkedPGR_2020-sample_LI.jpg
 

Attachments

  • 104113759004 diamond.pdf
    490 KB · Views: 4

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
Thank you for being so incredibly helpful! I reserved the diamond & attached the report above. There is one other stone I'm considering. I hope I can provide the same info and get your knowledgeable feedback on that one as well.
 

DejaWiz

Shiny_Rock
Joined
Apr 23, 2021
Messages
143
That's an ACA diamond, so...you're golden!
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
Let us know the other one you are considering and we will weigh in.
 

DejaWiz

Shiny_Rock
Joined
Apr 23, 2021
Messages
143
What are you considering "super ideal range"? My understanding of a super ideal is:
  • AGS000 report
  • True H&A symmetry
  • Advanced images (ASET, IS & H&A) to prove performance
  • Usually branded (ACA, Signature, CBI, etc) but not always
I agree the proportions shared looked very good and would make it a candidate to possibly be a super ideal. However, we do not yet have images to confirm cut precision and/or light performance.

Having good proportions doesn't guarantee a H&A stone.


I usually base my own parameters to mirror WF ACA parameters for what I consider super ideal proportions.

Thank you for mentioning the info regarding other characteristics, such as H&A symmetry and advanced images...those are crucial pieces for glitter geeks like myself.

Screenshot_20210608-113826.png
 

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
Let us know the other one you are considering and we will weigh in.

Here is the other diamond I'm considering. It is SI1, while the other one is VS2. But this one is a little larger. I like the idea of a larger stone, but I don't know how noticeable the difference would be btwn 1.53 carats and 1.657 carats. Is it better to go with VS2, even if SI1 paperwork says it's eye clean? I welcome feedback from this group!
 

Attachments

  • 104084513005 diamond.pdf
    405.9 KB · Views: 4

swingtime

Rough_Rock
Joined
May 1, 2021
Messages
18
Here is the other diamond I'm considering. It is SI1, while the other one is VS2. But this one is a little larger. I like the idea of a larger stone, but I don't know how noticeable the difference would be btwn 1.53 carats and 1.657 carats. Is it better to go with VS2, even if SI1 paperwork says it's eye clean? I welcome feedback from this group!
 

Attachments

  • 104084513005 diamond.pdf
    405.9 KB · Views: 5

DejaWiz

Shiny_Rock
Joined
Apr 23, 2021
Messages
143
Here is the other diamond I'm considering. It is SI1, while the other one is VS2. But this one is a little larger. I like the idea of a larger stone, but I don't know how noticeable the difference would be btwn 1.53 carats and 1.657 carats. Is it better to go with VS2, even if SI1 paperwork says it's eye clean? I welcome feedback from this group!


For me, that particular SI1 has a bit too much debris under the table, just based on the magnified videos.
It may very well be completely eye-clean and any inclusions might be concealable by conscientious mounting in a setting.
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
Here is the other diamond I'm considering. It is SI1, while the other one is VS2. But this one is a little larger. I like the idea of a larger stone, but I don't know how noticeable the difference would be btwn 1.53 carats and 1.657 carats. Is it better to go with VS2, even if SI1 paperwork says it's eye clean? I welcome feedback from this group!

I really like the proportions a lot. The smaller 55.8 table, 34.5/40.8 and 76 LGF's gets me pretty revved up.

However, those black inclusions are too much for my own tastes. WF states the stone is eye clean, but I would ask them to pull the stone and confirm that. I know the videos & images are 35-40x. I also know their standard definition of eye clean is 10" away with 20/20 vision & good lighting.

I tend to be more picky and would be at least 6" from my eyeballs and twisting and rotating that stone to make sure I didn't see a speck. I don't think it will meet that type of scrutiny. Maybe unfair on my part, but I just don't like the inclusions and would likely pass on this particular SI1 as they are just too much for my own preferences.

You see this in the videos pretty clearly as well as multiple images.

1623188842776.png

1623188783868.png
 

Wink

Rough_Rock
Trade
Joined
May 24, 2021
Messages
46
To avoid violating forum rules, I will not speak about the diamond shown above.

I will say that many times, the on line AGS reports look much worse than they do in real life. Seriously, it seems the AGS does much heavier markings on their on line reports than in the ones they deliver with the diamonds.

Often, in order to know whether or not you are going to like a diamond, you must see it in real life. Many a local client of mine has ended up walking away with a "bargain" diamond because it looked so horrid on line that no one on line would even look at it.

My advice, if you are looking at a VS2 or an SI1 and are worried about it being eye clean to your eyes, talk to your sales rep and if they say it is clean to their eyes, call it in with the knowledge that you can return it if you are not happy with it.

You may be doing yourself a huge favor.

Wink
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,110
Here are a couple of alternates that you may like and is reasonably close to the $14.8k wire price of the 1.537.

WF ACA 1.601 G-SI1 @ $14,366

About $500 cheaper than the wire price of the 1.537 and right at 0.20mm better spread. Double check with WF on it being eye clean, but I think it will check fine. I might ask them if either feather becomes noticeable as you twist & rotate the stone.

FYI, the 1.601 has a little larger table and shallower depth pushing some of the carat weight in the horizontal plane to increase spread, while still staying within ideal proportions.

Looking at the video, the stone still has plenty of fire so was not negatively affected. However, it's a wise use of carat weight and IMO gives you a little more bang for the buck in that regards.

https://www.diamdb.com/compare/1.54ct-round-7.37x7.39x4.57-vs-1.6ct-round-7.55x7.58x4.6/

Capture1.PNG


WF ACA 1.627 G-VS2 @ $15,698 wire

For about $900 more than the wire price of the 1.537 you can stay in a VS2 clarity, and that same 0.20mm gain in spread. Aside from clarity, the main differences being this stone has a slightly smaller table and more depth so a little more of that carat weight is pushed in the vertical plane so while it weighs a little more it doesn't necessarily have a larger spread.

https://www.diamdb.com/compare/1.54ct-round-7.37x7.39x4.57-vs-1.63ct-round-7.56x7.6x4.64/

Capture2.PNG


One final size comparison. The 1.601 vs the 1.627.

https://www.diamdb.com/compare/1.6ct-round-7.55x7.58x4.6-vs-1.63ct-round-7.56x7.6x4.64/

Capture3.PNG
 

diamondseeker2006

Super_Ideal_Rock
Premium
Joined
Jan 11, 2006
Messages
57,598
I personally would rather have a VS2 for an engagement ring. So I'd choose the one you have on reserve or the 1.62. But if you think size is the most important factor to her, then you could go with the 1.60 that Sledge linked if the 1.62 is above budget.
 
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