Please help with these diamond angles/numbers

[Ashleigh]

My friend and her bf are ring shopping. Despite sharing my experiences with online buying with her, they've decided to shop local. She noted numbers of 3 diamonds and asked me to check the numbers of her favourite. Her favorite also happened to be the largest diamond. To me, the numbers of the biggest stone is not the best. Another looks better. I asked if she like it better due to size but she said the largest is sparkliest. Usually I'd have rejected this stone but since she set her mind on it and asked for help, can you all please help me?

Table: 56
Depth 62.6
Ca 35.5
Pa 40.8
Gia triple x

No aset, shop refuses to release gia report number for fear that she will buy it elsewhere for less. Can you please tell me how this diamond will look like with those numbers so that I can tell her? Thank you.

 

[smilligan]

The numbers don't look that great to me. Looks like a GIA steep/deep diamond. I find it kind of odd that the shop refuses to release the GIA number, but it could be common practice. IDK. I wouldn't want to buy it without first seeing the certificate, though. Also, every diamond will look amazing under jewelry store lighting. Did she take it outside or look at it by a window? I think she's probably going for the biggest size without realizing what really matters. It's almost like impulse buying. It seems like a good idea now, but you'll probably regret it later.

 

[Ashleigh]

Smilingan, thanks for the response. Do you think that is a borderline steep-deep that can still look good?

It didn't even occur to me to wonder about the shop's refusal to release the Gia report. I wonder when they deem a customer serious enough to show the report.

I'm not sure if she viewed the diamond outside of the shop but I'm certain there's no window in that shop. There're hardly any jewelry shops with windows in my country. In fact, most shops in malls don't have windows.

 

[MissGotRocks]

Steep deep diamonds usually have light leakage. Enough to matter? Well, you'd really need an IS or ASET image to tell the whole story.

 

[Evilsports]

I think I would have turned around and walked away the minute a shop refused to provide me with all of the available information at their disposal, regardless of their reasoning.

 

[Ashleigh]

I think I would have turned around and walked away the minute a shop refused to provide me with all of the available information at their disposal, regardless of their reasoning.

Actually their reasoning seems ridiculous now that I think about it. If they show her the diamond, it means it must be an in-house stone. Then how can she buy it from others?

 

[smilligan]

I think I would have turned around and walked away the minute a shop refused to provide me with all of the available information at their disposal, regardless of their reasoning.

Actually their reasoning seems ridiculous now that I think about it. If they show her the diamond, it means it must be an in-house stone. Then how can she buy it from others?

Technically, they could have ordered it in for a customer. Usually they are allowed an "inspection" period. If this was the case, she could wait for the stone to be sent back and then purchase it somewhere else. Still, if she really wanted to do that, there are other ways of finding the diamond.

 

[WinkHPD]

Fear is a strange thing. In response there are responsible, silly, and out right stupid stupid reactions.

Personally I can understand not wanting to be shopped on the net, but come on, how difficult is it to show the client a copy of the cert, with or without redacting the report number. It is not like you can stop someone from shopping you, with or without that number.

In truth, your friend already has all the info necessary to find bunches of stones that match it on the net, if she wanted to, which she does not. Obviously, she knows she will pay more, and is happy doing so for the comfort of dealing locally and establishing a relationship with a local jeweler, which I applaud.

I do not applaud the myopia of the local jeweler who is so afraid of the net that he will not even show her the certificate. This creates, to me, the definite opinion that this is NOT THE JEWELER TO DEVELOP A RELATIONSHIP WITH.

If they are this small minded and afraid on a minor issue, how will they react if there is any kind of a problem? Will they be forthcoming and make it right? Or will they try to hide it for fear it could cost them money?

As an internet jeweler who was for many years a B&M jeweler, I have to say I am sad for your friend to be receiving such shoddy service. As a jeweler, I am sad for my unknown associate for not knowing better than to try to hide from the obvious when he should be adding value by providing better education and service. He is treating her as a lowly customer, instead of a valued client.

Wink

 

[Ashleigh]

Wink, how will the stone with those specs look? She said it's sparkly and I'd have thought it'd be slightly leaky. Don't know how to answer her. I want to help her but don't want to rain on her parade in case she does end up getting that diamond. When she first asked, I told her the second diamond looks better on paper as compared to this one.

 

[FirstTimeBuyer128]

Not an expert on the market, but when I was shopping for a diamond EVERY store showed me the GIA report. I would never buy a diamond from anywhere without seeing it - seems extremely shady they won't show it to you. I would not recommend dealing with that store.

 

[John P]

Wink, how will the stone with those specs look? She said it's sparkly and I'd have thought it'd be slightly leaky. Don't know how to answer her. I want to help her but don't want to rain on her parade in case she does end up getting that diamond. When she first asked, I told her the second diamond looks better on paper as compared to this one.

Hi Ashleigh.

The non-answer is due to a lack of information: Asking a cut specialist "How is 56 35.5 40.8 going to perform?" is like asking a model agent "Hey, I heard of a guy who's 5'9" and weighs 170...would you hire him to model?" ~ While there is some basic information involved (okay, he's height-weight proportionate) there is far more missing than there is present.

Here's a bullet list:
* 56 Table... Got it.
* 35.5 CA... Well, that's an average of eight measurements. How wide is the variance? Is it 34.9-36.0? Less? More?
*** Oh, and how much rounding is involved? Is it actually a 35.7 but rounded down? That makes a difference?
* 40.8 PA... Cool, but also an average of eight measurements. Same questions as the above.
*** Oh, and again the rounding is important, if it's rounded down from 40.9 and the CA was rounded down from 35.7
* 62.6 D... Either the girdle is 2% (meaning the diamond will need to be 1.06cts to reach 6.50mm) or there's indeed some depth that got rounded down in CA and PA as hypothesized.
* What about Lower Half length? Massive impact on performance character.
* Stars too, as they pair importantly with Table and Lower Halves in terms of character.
* And while no Upper Half information is included on the report, those details are influential in terms of brillianteering and cut precision.
* Ah yes. Optical cut precision. Also relevant and impossible to give meaningful info without, IMO.

Examples: 56 35.5 40.8 62.6 could look like either of the below or a hundred more variations (I produced these on the fly).


For the record, the one on the left is AGS 2 in performance. The one on the right is AGS 3 (via PGS).
Within those numbers the actual diamond could fall anywhere between AGS 1-5 and HCA 1.7-3.8.

 

[Ashleigh]

Thank you for the answer, John. Wish I could just email her your response but she won't understand though. I didn't know the performance can range from 1-5. That's pretty wide. Think I will tell her different combinations will produce different light performance and hopefully, she will move on from this stone.

 

[WinkHPD]

Thank you for the answer, John. Wish I could just email her your response but she won't understand though. I didn't know the performance can range from 1-5. That's pretty wide. Think I will tell her different combinations will produce different light performance and hopefully, she will move on from this stone.

Ashleigh,

What is really sad is that most jewelers would not understand it either. What is really wonderful is having someone like John to lay it all out and make it look easy. When John left the music world to become immersed in the diamond world he did it completely and has since become a teacher to most of us here. Those of us who tried to help him with his first diamond purchase and who were once his teachers have long since become his students.

His answer above, shows why so many of us in the trade hold him in our highest regard!

Wink

 

[Jim Summa]

Thank you for the answer, John. Wish I could just email her your response but she won't understand though. I didn't know the performance can range from 1-5. That's pretty wide. Think I will tell her different combinations will produce different light performance and hopefully, she will move on from this stone.

Ashleigh,

What is really sad is that most jewelers would not understand it either. What is really wonderful is having someone like John to lay it all out and make it look easy. When John left the music world to become immersed in the diamond world he did it completely and has since become a teacher to most of us here. Those of us who tried to help him with his first diamond purchase and who were once his teachers have long since become his students.

His answer above, shows why so many of us in the trade hold him in our highest regard!

Wink

Well said Wink, your not too bad an educator yourself.

 

[Ashleigh]

I'm glad that PS is a place where we can all learn about diamonds from the trade experts and prosumers.

 

[travlinman561]

According to the AGSL Proportion Charts (http://www.agslab.com/docs/pbcg/AGSLProportionCharts.pdf), a 56 table, 35.5 CA and 40.8 PA lies within the ideal range (on the edge); however, this does not necessarily mean that it will score an AGS 0.

 

[John P]

According to the AGSL Proportion Charts (http://www.agslab.com/docs/pbcg/AGSLProportionCharts.pdf), a 56 table, 35.5 CA and 40.8 PA lies within the ideal range (on the edge); however, this does not necessarily mean that it will score an AGS 0.

Travlinman, I'd just note that the AGSL Proportion Charts you linked apply to their 2D proportions-based DQR (Gold report) and not the superior 3D performance-based DQD (Platinum report) which is the only report capable of given AGS "0" for performance.

No grading charts exist for the Platinum Report, since each diamond must undergo ray-tracing to see how all 57 (or 5 facets interact together specifically. The AGSL publishes cut guidelines for manufacturers but they're general. While it's possible for a diamond matching the guidelines' numbers to earn the performance grade indicated it's in no way guaranteed: The final grade depends on appropriate minors, cut-consistency, optical precision, brillianteering and finish. So the guidelines are seen as a "best case" scenario.

Below are the guidelines for 56 table, 6mm. In 3D Platinum assessment 56 40.8 35.5 is a candidate for AGS 2, and falls in a borderline area +/-.

But the main point from my post above is the fallacy of "35.5" and "40.8" as givens. We cannot know the actual numbers. "35.5" and "40.8" are averages of multiple measurements which are further rounded to an unknown degree. The actual averages could be 35.3-40.7 (AGS 0-1) 35.7-40.9 (AGS 3-4) or somewhere between. We cannot know exactly. Furthermore, without ideal-scope, ASET and such images we cannot know cut-consistency, precision or brillianteering details which also influence the final grade.

The one clue we have beyond guesswork is the 62.6 depth, which mathematically indicates either a girdle carrying some weight or angles on the steeper side (or both) making AGS 0 quite unlikely.

I hope the extra information is interesting. Cut guidelines below.


ETA: I've asked the admin to permit the graphic above to open at full size. I realize it's hard to read as-is.

 

[John P]

Thank you for the answer, John. Wish I could just email her your response but she won't understand though. I didn't know the performance can range from 1-5. That's pretty wide. Think I will tell her different combinations will produce different light performance and hopefully, she will move on from this stone.

Ashleigh,

What is really sad is that most jewelers would not understand it either. What is really wonderful is having someone like John to lay it all out and make it look easy. When John left the music world to become immersed in the diamond world he did it completely and has since become a teacher to most of us here. Those of us who tried to help him with his first diamond purchase and who were once his teachers have long since become his students.

His answer above, shows why so many of us in the trade hold him in our highest regard!

Wink

Wow. Feeling the love.

Wink are you seeking some favor from me? ...Whatever it is, you got it

I'm glad that PS is a place where we can all learn about diamonds from the trade experts and prosumers.

Touche' - And thanks too, Jim & Ashleigh.

 

[Karl_K]

My usual reply about those combinations is that the GIA numbers and grade are useless on these stones to determine how they will perform so more information is needed.

 

[John P]

My usual reply about those combinations is that the GIA numbers and grade are useless on these stones to determine how they will perform so more information is needed.

...Saying in 20 words what took me 200+

 

[Ashleigh]

My usual reply about those combinations is that the GIA numbers and grade are useless on these stones to determine how they will perform so more information is needed.

...Saying in 20 words what took me 200+

John, your 200+ post helps me better understand why having just that 4 numbers is useless. I'm sure it will benefit others in future too.

On the other hand, I can just quote Karl's post to my friend in response to her question. Thanks, Karl

John, Karl, I actually have a question on cavity in diamonds which has gotten very few response as I suppose only the trade experts have the answer. I'm really curious about my observations. Can you please take a look at that thread when you're free. Thank you.