Let's Play Detective ... your vote/input appreciated

[Rhino]

Ok... prosumers and consumers. Here is an interesting diamond to learn from.

Person comes on the forum looking for a diamond. They want a diamond that will qualify as top optics in the most conservative labs (GIA/AGS).

Assuming polish/symmetry are both Ideal/Excellent what would your counsel be?

In the graphic you have a live ASET image, a computer generated ASET image (based on an HD scan), the proportions of the diamond and its HCA score. I want to know your answer and why.

If you have questions feel free to ask.

Kind regards,
Rhino

 

[mwilliamanderson]

It looks like perfection to me! Is this a trick question?

 

[ame]

I chose option two, and my only legit reasoning is that GIA has bizarre criteria. The angles to me scream AGS Ideal, though I'd obviously prefer a smaller table

 

[MissGotRocks]

I'm thinking it would pass in both labs but I'm guessing that AGS would like to see a better pavilion angle - more like 40.8 or 40.9 with that crown angle.

 

[Christina...]

Proportions appear to be in range for top cut from both labs. I'm not seeing any red flags from either ASET. You mentioned that consumer wants top optics...does this include top optical symmetry....HA? If this is important to the consumer I would advise requesting a hearts view of the stone. If not I would suggest that the stone was worth a closer examination and suggest that they contact the vendor for a gemological assessment...because I know Jon and other vendors will catch whatever it is I am missing.

 

[diamondseeker2006]

I'd have to know the clarity. And I'd also like to see the magnified image of the stone.

 

[Rhino]

Proportions appear to be in range for top cut from both labs. I'm not seeing any red flags from either ASET. You mentioned that consumer wants top optics...does this include top optical symmetry....HA? If this is important to the consumer I would advise requesting a hearts view of the stone. If not I would suggest that the stone was worth a closer examination and suggest that they contact the vendor for a gemological assessment...because I know Jon and other vendors will catch whatever it is I am missing.

A kind thanks for the votes and input so far. Good question Christina. Hearts & Arrows pertains to the level of craftsmanship we typically refer to as Optical Symmetry and at this point in time is not graded by GIA or AGS. So, in accord with their grade settings and also for the sake of this example it doesn't need to be H&A.

Kind regards,
Rhino

 

[Rhino]

I'd have to know the clarity. And I'd also like to see the magnified image of the stone.

Muahahah! I like the way you think Watson... woops... diamondseeker! While it is true that there are other gemological features about a diamond that CERTAINLY does impact it's optics and transparency it's not the clarity in this scenario. In fact this particular diamond is a VVS2.

 

[Supersleuth50]

Two GIA/AGS diamonds of the same graded colour will look to most people as if they are the same colour.
Two GIA/AGS diamonds of the same graded clarity will look to most people very similar in clarity when they look at them under x10.
Two GIA/AGS diamonds of the same graded size will look to most people as if they are of a similar size.
Two GIA/AGS diamonds of the same graded cut can look, even to the most casual of observers, very different from each other.


Why is this? A diamond is like a kaleidoscope and a tiny change in angle can result in a different looking diamond with a different pattern and size of sparkle and therefore a different appearance. It can also cause light performance to vary.

When GIA and AGS grade their diamonds they do not guarantee that their ideal cut diamonds are the best performing diamonds. In fact, some of them will be better than others. Equally, there are diamonds that are outside the excellent cut category that are fantastic performers.

If you were to ask me to recommend a diamond to someone without seeing it beforehand I would get a AGS Ideal cut with a good Holloway Score. This wouldn't guarantee me a top performing diamond but it would maximise my chances of getting one. I would choose AGS over GIA because its criteria aren't as wide and therefore the probability of a good diamond increases. Gary Holloway invented the Holloway score and his score favours the diamonds that he likes. But he is an experienced gemologist and so I think using the Holloway score would be very useful.

What I would prefer to do, in a perfect scenario, would be to order several AGS/GIA diamonds, all excellent cut, all good Holloway scores, to look at. In addition I would like the gemologist to send me a 'wild'card', a top performing diamond outside these stringent criteria. This is because I think that there is the occasional amazing diamond that on paper isn't so good but in reality is a wonderful surprise to everyone. An excellent gemologist would spot this and send it to me. I would then examine all the diamonds and choose the one that sparkled most pleasingly.

In your scenario you haven't told me that I'm not allowed to look at it. I have therefore decided that I haven't enough information. I would expect this diamond to be pretty good but there is always a possibility that I might be unlucky. I want the person to be happy and admire my diamond-choosing abilities. I would therefore look at the diamond with my own eyes before making a recommendation.

Hope that this is helpful. If you feel like sending me a wild card diamond I would be happy to look at it.

 

[Supersleuth50]

I would also consider hearts and arrows diamonds although one of labs has looked at this and has not found that people prefer them particularly. Again it's about maximising the chances of choosing a great diamond.

Not all hearts and arrows diamonds look alike either so I'm still back to 'not enough information' and 'I need to look at it'.

Best wishes,

SuperSleuth

P.S. My diamond is a hearts and arrows diamond. I find I like order and disorder. I quite like crushed ice radiants too.

 

[Ashleigh]

My impression is that GIA has greater tolerance of combinations falling into their Excellent category hence this diamond will make their Excellent grade. On the other hand, 34 crown is usually paired with 40.8 pavilion, 36 c with 40.6 p, which was what I was looking for. I recalled telling you I couldn't find that combo though. 34 c should be paired with 40.7 p at least (I suppose) to make their Ideal grade. So I don't think this diamond will make their Ideal grade unless they round pavilion up to 40.7. I think GIA does more rounding than AGS?

Btw, does 34.5-35 c paired with 40.6 p give great fire assuming 55-56 table and 60-62 depth? I am not concerned about the GIA/AGS grade nor HCA score. What effect does 41 p have on diamond given 55-56 table, 60-62 depth? 41p must be paired with what crown? I'm onto my next upgrade despite the last upgrade only a few months back. Thank you.

 

[Christina...]

Proportions appear to be in range for top cut from both labs. I'm not seeing any red flags from either ASET. You mentioned that consumer wants top optics...does this include top optical symmetry....HA? If this is important to the consumer I would advise requesting a hearts view of the stone. If not I would suggest that the stone was worth a closer examination and suggest that they contact the vendor for a gemological assessment...because I know Jon and other vendors will catch whatever it is I am missing.

A kind thanks for the votes and input so far. Good question Christina. Hearts & Arrows pertains to the level of craftsmanship we typically refer to as Optical Symmetry and at this point in time is not graded by GIA or AGS. So, in accord with their grade settings and also for the sake of this example it doesn't need to be H&A.

Kind regards,
Rhino

I responded using my kindle last night and for some reason the fact that this was poll didn't show at the top of my screen so I assumed you were just asking if we felt the stone was a safe option for the consumer. In fact Ame's response confused me, I was thinking WTH is option 2?

I actually do have a question for you now....is this stone similar to the one that was being discussed on another thread recently? I don't think that it is the same stone...proportions are different, but I'm guessing that this one may be as mysterious as that particular one? In which case, I'm going to change my initial thought that both would receive EX/ID from both GIA and AGS to that this particular stone is NOT a GIA EX candidate, but would be an AGS0 candidate. Though I still couldn't tell you why the downgrade by GIA, according to Octonus this stone would qualify for EX.....but not AGS0, so..... So now that I realize this is a poll asking a specific question, I will now official place my vote.

 

[Rhino]

Proportions appear to be in range for top cut from both labs. I'm not seeing any red flags from either ASET. You mentioned that consumer wants top optics...does this include top optical symmetry....HA? If this is important to the consumer I would advise requesting a hearts view of the stone. If not I would suggest that the stone was worth a closer examination and suggest that they contact the vendor for a gemological assessment...because I know Jon and other vendors will catch whatever it is I am missing.

A kind thanks for the votes and input so far. Good question Christina. Hearts & Arrows pertains to the level of craftsmanship we typically refer to as Optical Symmetry and at this point in time is not graded by GIA or AGS. So, in accord with their grade settings and also for the sake of this example it doesn't need to be H&A.

Kind regards,
Rhino

I responded using my kindle last night and for some reason the fact that this was poll didn't show at the top of my screen so I assumed you were just asking if we felt the stone was a safe option for the consumer. In fact Ame's response confused me, I was thinking WTH is option 2?

I actually do have a question for you now....is this stone similar to the one that was being discussed on another thread recently? I don't think that it is the same stone...proportions are different, but I'm guessing that this one may be as mysterious as that particular one? In which case, I'm going to change my initial thought that both would receive EX/ID from both GIA and AGS to that this particular stone is NOT a GIA EX candidate, but would be an AGS0 candidate. Though I still couldn't tell you why the downgrade by GIA, according to Octonus this stone would qualify for EX.....but not AGS0, so..... So now that I realize this is a poll asking a specific question, I will now official place my vote.

 

[gemmyblond]

OK, I'll take a shot at this (and hope to learn!)...I'd want to know the carat weight, first and foremost. The graphic says that Spread is (only) VG. This could lead one to suspect that perhaps the stone was cut to make a certain weight and faces up on the small side for that ct wt.
I'd also want to check for painting/digging out of the girdle (espec in light of the above) as a technique to make a given weight. (I don't know how to check for this using scans...). So I'd want to see the stone in person too.
Finally, I thought I read somewhere on PS that a quite low HCA score isn't necessarily great, but I honestly can't recall much beyond that (which may not even be accurate).

Thanks for posting the query - hope I can learn a bunch from where this goes!

 

[Dreamer_D]

Is the buyer looking for an H&A stone?

I can't read the proportion scan, can you report it larger?

 

[Laila619]

A 34 crown with a 40.6 pav is not my favorite. Too shallow of a crown with that pav angle; there could be obstruction issues. I would advise that person to keep looking.

 

[Sidius]

I'm by no means an expert, I've only been on here and researching diamonds for about a month lol. I voted not enough information. If we're basing it strictly on the first post, as someone else noted, there's no clarity grade (although we do know now that it's a VVS2) and no color grade. The ASET look good to someone who doesn't have much experience with them and the HCA score is pretty exceptional. I would think without more information that it would get an AGS0 rating, but again, I'm no expert.

 

[Rhino]

OK, I'll take a shot at this (and hope to learn!)...I'd want to know the carat weight, first and foremost. The graphic says that Spread is (only) VG. This could lead one to suspect that perhaps the stone was cut to make a certain weight and faces up on the small side for that ct wt.
I'd also want to check for painting/digging out of the girdle (espec in light of the above) as a technique to make a given weight. (I don't know how to check for this using scans...). So I'd want to see the stone in person too.
Finally, I thought I read somewhere on PS that a quite low HCA score isn't necessarily great, but I honestly can't recall much beyond that (which may not even be accurate).

Thanks for posting the query - hope I can learn a bunch from where this goes!

Good questions gemmyblond.

This particular diamond does happen to weigh 1.21ct so the cutter wasn't necessarily looking to break a particular threshold in relation to "magic numbers" for the weight.

It is also important that the PS community understand that the HCA penalizes diamonds with a "Very Good" spread as opposed to "Excellent" that are 110% perfectly fine. It is an extremely ridiculous downgrade in the HCA system because this diamond happens to have a depth of 60.7%. Many perfectly fine diamonds have depths that reach into the 61 and even low 62% depth ranges. GIA/AGS will begin penalizing diamonds with depths at or approaching the 63% zone.

Your request of wanting to know painting/digging is valid as well perhaps for another future post but it's not the case in this particular diamond. You can see evidence of painting/digging data via ASET (not IdealScope and most red reflectors) but you can see the precise degree of painting/digging critically in Helium Reports.

Thank you for your comments/questions/votes and participation.

 

[Rhino]

Is the buyer looking for an H&A stone?

I can't read the proportion scan, can you report it larger?

1. Nope. Doesn't need to be H&A. Only that the optics safely pass GIA Ex and AGS Ideal for cut.

2. Sure. I had uploaded the graphic in another thread without the poll which I requested to be deleted and it appears this graphic does not come through in the full resolution I had made it in. I'm reuploading with a new file name so hopefully this will work.

{edited to add ... woof I see it didn't work} I'll upload proportions for ya though so its more readable.

 

[Rhino]

Two GIA/AGS diamonds of the same graded colour will look to most people as if they are the same colour.
Two GIA/AGS diamonds of the same graded clarity will look to most people very similar in clarity when they look at them under x10.
Two GIA/AGS diamonds of the same graded size will look to most people as if they are of a similar size.
Two GIA/AGS diamonds of the same graded cut can look, even to the most casual of observers, very different from each other.


Why is this? A diamond is like a kaleidoscope and a tiny change in angle can result in a different looking diamond with a different pattern and size of sparkle and therefore a different appearance. It can also cause light performance to vary.

When GIA and AGS grade their diamonds they do not guarantee that their ideal cut diamonds are the best performing diamonds. In fact, some of them will be better than others. Equally, there are diamonds that are outside the excellent cut category that are fantastic performers.

If you were to ask me to recommend a diamond to someone without seeing it beforehand I would get a AGS Ideal cut with a good Holloway Score. This wouldn't guarantee me a top performing diamond but it would maximise my chances of getting one. I would choose AGS over GIA because its criteria aren't as wide and therefore the probability of a good diamond increases. Gary Holloway invented the Holloway score and his score favours the diamonds that he likes. But he is an experienced gemologist and so I think using the Holloway score would be very useful.

What I would prefer to do, in a perfect scenario, would be to order several AGS/GIA diamonds, all excellent cut, all good Holloway scores, to look at. In addition I would like the gemologist to send me a 'wild'card', a top performing diamond outside these stringent criteria. This is because I think that there is the occasional amazing diamond that on paper isn't so good but in reality is a wonderful surprise to everyone. An excellent gemologist would spot this and send it to me. I would then examine all the diamonds and choose the one that sparkled most pleasingly.

In your scenario you haven't told me that I'm not allowed to look at it. I have therefore decided that I haven't enough information. I would expect this diamond to be pretty good but there is always a possibility that I might be unlucky. I want the person to be happy and admire my diamond-choosing abilities. I would therefore look at the diamond with my own eyes before making a recommendation.

Hope that this is helpful. If you feel like sending me a wild card diamond I would be happy to look at it.

Good input SS. It would be an internet purchase and you can't see the diamond before you pay for it (unless of course you travel to the store that has it).

 

[nowicanseethemoon]

I haven't a clue, but I enjoy reading everyone's posts and learning more. Modern diamonds are still a mystery to me.

 

[Rhino]

Let's try this Dreamer.

 

[GamGam]

Jon,
I have a stone with identical numbers, and it is graded GIA EXcellent!! And I think it would not get the top rating from AGS. However, the stone I own is absolutely beautiful. Very firey and brilliant with no obstruction. Mine is 1.58 weight and VS1 clarity (7.52x7.54x4.57)and I color. When I'm at the basketball arena, it is a pyrotechnics show! I couldn't be happier with it.

GamGam

 

[Supersleuth50]

Hi Rhino,

I would just maximise my chances of an excellent stone. AGS, good Holloway score, Hearts & Arrows, nice angles, reasonable clarity and colour. Then I would tell the buyer to get the stone on approval, put it on the house insurance, take it from room to room to see it in different lights, take it to a reputable jeweller/gemologist and put it on the table and say, "Can you match this?". I'd then get the buyer to look at their diamond and compare it with lots of other diamonds and choose their favourite.

This is good advice. In the end we should respect the knowledge but people need to buy the diamonds tey like the most.

By the way, the stone may be too big. I suspect that for round brilliants the Goldilocks zone for diamonds complementing the average woman's hand is around 0.7 carats. Much above this size and the diamond could take over.

 

[Supersleuth50]

As always, a little bit too abrupt. There are beautiful stones of every size. Just me being opinionated, as usual.

 

[diamondseeker2006]

If you stick around here a little more, Supersleuth, you will find that the "goldilocks zone for complimenting a woman's hand" is quite a bit above .7! That is a nice size, but many will disagree that larger stones are in any way gaudy or not complementary to the wearer!

 

[diamondseeker2006]

JON! The girdle thickness is the problem, right??? That would kick it into GIA very good????????????????

 

[Christina...]

If you stick around here a little more, Supersleuth, you will find that the "goldilocks zone for complimenting a woman's hand" is quite a bit above .7! That is a nice size, but many will disagree that larger stones are in any way gaudy or not complementary to the wearer!

Totally agree!

 

[Rhino]

Alright ... first, here's how it fares in the AGS system.

Amongst 29 votes garnered thus far 14 of them voted with confidence that it would make AGS Ideal.

There were 2 options that supported this, namely those answers "Safely AGS Ideal but not GIA Ex" and "Safe bet in both labs".

Truth is it doesn't qualify for AGS Ideal.

Here are the PGS results below. You'll note the primary hit is in the metric of "contrast" with secondary hits in "brightness" and "dispersion".

You may be thinking how can such a seemingly perfect ASET result take a hit in contrast? Fact is AGS considers two "contrast" readings that are not reflected in the ASET imagery you see online both with black backgrounds as well as the illuminated background we use in our own photography. ASET's you see that are online only take into account a 30 degree angular spectrum for head/body shadow.

In AGS' system there is an assessment for a 30 degree spectrum obscuration (covering the high angles of 75-90 degree spectrum, seen as blue in the ASET) and there is also an assessment for a 40 degree angular spectrum that consumers generally never see covering an 80-90 degree angular spectrum.

It is within that 40 degree angular spectrum wherein this diamond takes a hit in the optics, thus causing it to get a "1" in Light Performance deduction.

Why is this important? Even if a consumer utilizes a 30 degree angular spectrum as opposed to 40 in their everyday viewing habits, and the diamond can look perfectly fine to those folks ... the diamond will not fetch top value if it is not AGS Ideal but AGS 1 in Light Performance. Plain and simple. Later I'll post the GIA results.

If ya'll have any questions feel free to ask.

Primary question to our readers ... What does this teach you?

 

[pyramid]

Maybe it teaches us, that we are paying for something we can't see like vvs2, D, and 1.00carat as opposed to 0.99, but this
is the Cut version of it.

So the AGS ideal cut is elusive unless you are buying one as it has a secret that only a diamond dealer like Rhino would know of,
given that people looking for education are going quite happily along with the Asset scope picture not knowing there is a higher
level which should be thought about OR has the AGS discovered something more desirable for better light performance.

Is it a cheat, and not important?