Need some seasoned PSers to weigh in!

[jrowinski]

I've put a diamond on hold. Would anyone care to comment on my selection? I'm having last minute doubts...

To me, this diamond looks like a good buy. Wanted to get a second opinion.

http://www.goodoldgold.com/diamond/10831/

It was listed for $7,300.

I'm sure its a rather subjective question, but given the my criteria ( 1CT, 'H' or higher, SI1 or higher, AGS0/GIA triple X) how does this diamond stack up?

This is my first diamond buying experience and so far I've learned a lot from this community, thanks again!

 

[tyty333]

Well it is an AGS000 stone so I would say its going to be a pretty nice stone.

 

[ame]

I think it looks pretty great! I personally prefer a table closer to 55, but otherwise that looks pretty great, and agreed, it's an AGS000 so that's a pretty good likelihood it's gonna knock your socks off.

 

[AprilBaby]

Gorgeous!

 

[sherryd]

The stats on that diamond are similar to mine, and all I can say is get your sunglasses out because it's bright!
Beautiful choice, please come back with hand shots!!!

 

[jrowinski]

Thanks for the feedback!

I'm pleased with the optical symmetry of the diamond, but would like to understand more about the proportions, facet proportions, and the girdle cut. What could be improved when assessing the diamonds overall appearance.

From my understanding, even though this diamond is a Ideal AGS cut, there a few more factors which will contribute to the brightness and scintillation. The crown angle isn't perfect, the table is perhaps slightly large and I don't fully understand the inconsistencies within the girdle.

Basically, I'm curious about the diamonds shortcomings and how this all translates into real world interpretation.

 

[John P]

Thanks for the feedback!

I'm pleased with the optical symmetry of the diamond, but would like to understand more about the proportions, facet proportions, and the girdle cut. What could be improved when assessing the diamonds overall appearance.

From my understanding, even though this diamond is a Ideal AGS cut, there a few more factors which will contribute to the brightness and scintillation. The crown angle isn't perfect, the table is perhaps slightly large and I don't fully understand the inconsistencies within the girdle.

Basically, I'm curious about the diamonds shortcomings and how this all translates into real world interpretation.

Hi jrowinski.

RE the bolded type: A diamond's primary measurements all work together, so there's not a "perfect" crown angle. Can you elaborate? Also, tables from 53-59 are considered small in the overall scope of industry production. Moreover, for a 34.9/40.9 diamond the choice of 57% (rather than 53-56%) creates a crown height closer to 15%, which is a target for many cut-focused cutters as it relates to balanced visual qualities in a near-Tolkowsky make. Finally, I'm not sure what inconsistencies you're spotting in the girdle; technically it's a classic Thin to Medium with high cut consistency, as seen on the Helium report... So, as a self-proclaimed cut-nerd, I'm interested in knowing what you see as shortcomings, and why.

 

[ame]

Thanks for the feedback!

I'm pleased with the optical symmetry of the diamond, but would like to understand more about the proportions, facet proportions, and the girdle cut. What could be improved when assessing the diamonds overall appearance.

From my understanding, even though this diamond is a Ideal AGS cut, there a few more factors which will contribute to the brightness and scintillation. The crown angle isn't perfect, the table is perhaps slightly large and I don't fully understand the inconsistencies within the girdle.

Basically, I'm curious about the diamonds shortcomings and how this all translates into real world interpretation.

Hi jrowinski.

RE the bolded type: A diamond's primary measurements all work together, so there's not a "perfect" crown angle. Can you elaborate? Also, tables from 53-59 are considered small in the overall scope of industry production. Moreover, for a 34.9/40.9 diamond the choice of 57% (rather than 53-56%) creates a crown height closer to 15%, which is a target for many cut-focused cutters as it relates to balanced visual qualities in a near-Tolkowsky make. Finally, I'm not sure what inconsistencies you're spotting in the girdle; technically it's a classic Thin to Medium with high cut consistency, as seen on the Helium report... So, as a self-proclaimed cut-nerd, I'm interested in knowing what you see as shortcomings, and why.

Thanks for chiming in John!

 

[jrowinski]

Thanks for the feedback!

I'm pleased with the optical symmetry of the diamond, but would like to understand more about the proportions, facet proportions, and the girdle cut. What could be improved when assessing the diamonds overall appearance.

From my understanding, even though this diamond is a Ideal AGS cut, there a few more factors which will contribute to the brightness and scintillation. The crown angle isn't perfect, the table is perhaps slightly large and I don't fully understand the inconsistencies within the girdle.

Basically, I'm curious about the diamonds shortcomings and how this all translates into real world interpretation.

Hi jrowinski.

RE the bolded type: A diamond's primary measurements all work together, so there's not a "perfect" crown angle. Can you elaborate? Also, tables from 53-59 are considered small in the overall scope of industry production. Moreover, for a 34.9/40.9 diamond the choice of 57% (rather than 53-56%) creates a crown height closer to 15%, which is a target for many cut-focused cutters as it relates to balanced visual qualities in a near-Tolkowsky make. Finally, I'm not sure what inconsistencies you're spotting in the girdle; technically it's a classic Thin to Medium with high cut consistency, as seen on the Helium report... So, as a self-proclaimed cut-nerd, I'm interested in knowing what you see as shortcomings, and why.

Thanks for chiming in John!

Hi John,

I'm still taking all this in, so bare with me.

According to the helium report, the symmetry of the crown angle was rated at a 'VG' opposed to an 'EX'. I don't really know how that translates to visual differences but was curious.

The helium thickness graph shows that the dips throughout the mains and halves aren't consistent throughout the graph. I was under the impression that a ideal classic girdle is the same thickness throughout the halves and mains all the way through the graph.

Then again, this was my first time reading a helium report. So that certainly doesn't help.

To be honest, I have no idea what i'm talking about. Everything was peachy when I was just dealing with a couple of search parameters. Now i'm concerned about buying a AGS0 thats dull in comparison to another.

How would you grade this diamonds cut overall?

 

[jrowinski]

GOG made me a comparison video of the diamond and a similar ideal. To me it almost seems like the one on the right seems brighter.

http://youtu.be/-2RfysNg7BQ

 

[JulieN]

Do you have a link to the second stone?

 

[John P]

Hi John, I'm still taking all this in, so bare with me. ...

First of all: Compliments on chasing after these details. Most people don't concern themselves with the level of cut-analysis you're wading-into, and that's fine. I enjoy this kind of conversation though because, in a pedantic way, I also like examining the whys and wherefores. With that said, a lot of what I'll lay out below is flat-out negligible in terms of visual results.

According to the helium report, the symmetry of the crown angle was rated at a 'VG' opposed to an 'EX'. I don't really know how that translates to visual differences but was curious.

That comment relates to the deviation from average, which is 0.64 of a degree. From experience, such a deviation is common in well-cut diamonds. No cut metric (AGS 0 GIA EX) would ever penalize it. In fact, in my travels I see Ideal and EX diamonds with crown angle deviations nearly 3X as wide.

You may be interested to know that 3D scanners like Sarin, Helium and Ogi produce are primarily used by manufacturers. It's extremely rare for consumers to see this level of facet-by-facet detail for a diamond (welcome to Pricescope). Go into Tiffany, Jared or your nearest HOF dealer and examine some loose diamonds. Then ask them for the 57-Facet Manufacturer's Reports and watch their eyes glaze over.

I understand the genesis of your question, as "VG" or "G" are inclined to stick out here. But, taken in context, this is like seeing a collection of extreme-extreme close-ups of your favorite supermodel. You turn a page and say "What's that scary lunar crater!?" Oh... It's nothing more than a normal pore on her face when you zoom back out to reality.

The helium thickness graph shows that the dips throughout the mains and halves aren't consistent throughout the graph. I was under the impression that a ideal classic girdle is the same thickness throughout the halves and mains all the way through the graph.

You've correctly identified the "ying" to the CA "yang" discussed above. The deviation in the crown mains will be echoed in other crown facets as a natural by-product. You can see this where the girdle and mains connect; the meet-point at 3.7% will be your shallow angle (34.85°) and the meet-point at 3.1% will be the steep one (35.49°). These echoes are also reflected in the star and upper girdle facet data on the Helium.



By the way, this is all normal. In fact this is a well-fashioned specimen. There is no such thing as a perfect "wire-frame" diamond. It's the hardest natural known substance, with soft and hard areas, crystal graining and a chaos of natural internal obstacles, undergoing white-hot polishing with a goal of being accurate at some incredible tiny level. It's astonishing that fine-make is possible.

Whenever a diamond is blocked (the mains are established) there are reasons for deviation. Some is slight, some is blatant, depending on the planners, the tools, the laborers and the material. Cases of significant inconsistency may result from assembly-line planning, average equipment and average labor. In a case like this there was clearly care in the planning and only slight deviation. Why the deviation? Perhaps an inclusion was chased out, a natural was avoided, the shape of the rough demanded it or graining pushed it that way.

It's pretty cool that the cross-worker (who cleans up after blocking) was able to manipulate the upper girdle and star facets in a way that resulted in no painting/digging problems, and - especially - preserved the H&A pattern that is present.

Setting the Helium report aside, I always like to look at the true, natural data available via computer. Those are the images, which are more reliable and telling then scanned reports, which are subject to some degree of mechanical error. In this case the images are all robust.

To be honest, I have no idea what i'm talking about. Everything was peachy when I was just dealing with a couple of search parameters.

I totally understand. It's easy to get analysis-paralysis. It may help to know that you're now at a micro-level that goes beyond practical visual influence, except in the case of resultant optical precision. Someone called this kind of dialogue "nano-tech" in the past...Great term.

Now i'm concerned about buying a AGS0 thats dull in comparison to another. How would you grade this diamonds cut overall?

As a trade member I'm not permitted to say "do" or "don't." I can say that, while videos are helpful, I don't find them decisive at all in such comparisons. My advice is to place your trust in a respected expert(s) who has the diamond(s) you're considering in-hand, then dialogue with those folks and make your decision. The most consumer-friendly sellers have liberal inspection and return periods so you're covered.

Most of all, enjoy the process - which I think you are?

 

[Tekate]

the one on the right seems equal to me but seems a teeny bit bigger.. both are stunning, gorgeous stones..

GOG made me a comparison video of the diamond and a similar ideal. To me it almost seems like the one on the right seems brighter.

http://youtu.be/-2RfysNg7BQ

 

[Christina...]

Hi John, I'm still taking all this in, so bare with me. ...

First of all: Compliments on chasing after these details. Most people don't concern themselves with the level of cut-analysis you're wading-into, and that's fine. I enjoy this kind of conversation though because, in a pedantic way, I also like examining the whys and wherefores. With that said, a lot of what I'll lay out below is flat-out negligible in terms of visual results.

According to the helium report, the symmetry of the crown angle was rated at a 'VG' opposed to an 'EX'. I don't really know how that translates to visual differences but was curious.

That comment relates to the deviation from average, which is 0.64 of a degree. From experience, such a deviation is common in well-cut diamonds. No cut metric (AGS 0 GIA EX) would ever penalize it. In fact, in my travels I see Ideal and EX diamonds with crown angle deviations nearly 3X as wide.

You may be interested to know that 3D scanners like Sarin, Helium and Ogi produce are primarily used by manufacturers. It's extremely rare for consumers to see this level of facet-by-facet detail for a diamond (welcome to Pricescope). Go into Tiffany, Jared or your nearest HOF dealer and examine some loose diamonds. Then ask them for the 57-Facet Manufacturer's Reports and watch their eyes glaze over.

I understand the genesis of your question, as "VG" or "G" are inclined to stick out here. But, taken in context, this is like seeing a collection of extreme-extreme close-ups of your favorite supermodel. You turn a page and say "What's that scary lunar crater!?" Oh... It's nothing more than a normal pore on her face when you zoom back out to reality.

The helium thickness graph shows that the dips throughout the mains and halves aren't consistent throughout the graph. I was under the impression that a ideal classic girdle is the same thickness throughout the halves and mains all the way through the graph.

You've correctly identified the "ying" to the CA "yang" discussed above. The deviation in the crown mains will be echoed in other crown facets as a natural by-product. You can see this where the girdle and mains connect; the meet-point at 3.7% will be your shallow angle (34.85°) and the meet-point at 3.1% will be the steep one (35.49°). These echoes are also reflected in the star and upper girdle facet data on the Helium.



By the way, this is all normal. In fact this is a well-fashioned specimen. There is no such thing as a perfect "wire-frame" diamond. It's the hardest natural known substance, with soft and hard areas, crystal graining and a chaos of natural internal obstacles, undergoing white-hot polishing with a goal of being accurate at some incredible tiny level. It's astonishing that fine-make is possible.

Whenever a diamond is blocked (the mains are established) there are reasons for deviation. Some is slight, some is blatant, depending on the planners, the tools, the laborers and the material. Cases of significant inconsistency may result from assembly-line planning, average equipment and average labor. In a case like this there was clearly care in the planning and only slight deviation. Why the deviation? Perhaps an inclusion was chased out, a natural was avoided, the shape of the rough demanded it or graining pushed it that way.

It's pretty cool that the cross-worker (who cleans up after blocking) was able to manipulate the upper girdle and star facets in a way that resulted in no painting/digging problems, and - especially - preserved the H&A pattern that is present.

Setting the Helium report aside, I always like to look at the true, natural data available via computer. Those are the images, which are more reliable and telling then scanned reports, which are subject to some degree of mechanical error. In this case the images are all robust.

To be honest, I have no idea what i'm talking about. Everything was peachy when I was just dealing with a couple of search parameters.

I totally understand. It's easy to get analysis-paralysis. It may help to know that you're now at a micro-level that goes beyond practical visual influence, except in the case of resultant optical precision. Someone called this kind of dialogue "nano-tech" in the past...Great term.

Now i'm concerned about buying a AGS0 thats dull in comparison to another. How would you grade this diamonds cut overall?

As a trade member I'm not permitted to say "do" or "don't." I can say that, while videos are helpful, I don't find them decisive at all in such comparisons. My advice is to place your trust in a respected expert(s) who has the diamond(s) you're considering in-hand, then dialogue with those folks and make your decision. The most consumer-friendly sellers have liberal inspection and return periods so you're covered.

Most of all, enjoy the process - which I think you are?

As always, John is the master of putting it all back into perspective.

 

[jrowinski]

Thanks for breaking that down for me, that definitely cleared up a lot of confusion. I really appreciate the craftsmanship behind the cutting process and am accepting that these are all handmade beauties which slightly deviate from one another. You're right this level of detail is simply amazing. So when viewed in that light, I'm growing content with my selection.

Looking at the Megascope graph, what would need to be improved within the diamond to see better results? Curious how that calculates those results. Likely, that is something hard to gauge?

My last question is, why does the Sarin graphic show that the '12 o'clock' arrow shaft as dark-red opposed to dark-blue like the others? Is that a contrast or leakage issue? Could that be what i'm seeing om the comparison video? Almost, seems like the left (selected diamond) in its ''7 o'clock' shaft/facets are not reflecting too well in the diamonddock.

 

[John P]

Looking at the Megascope graph, what would need to be improved within the diamond to see better results? Curious how that calculates those results. Likely, that is something hard to gauge?

I'm sure we can design a diamond that maxes out the three bars, but it may not be an improvement. It's a system with no scientific theory and no peer-review. If this is important to you I suggest you speak to the seller.

Here's a past thread with discussion and links to similar conversations.
https://www.pricescope.com/community/threads/gemex-v-megascope-technical-question.90742/

My last question is, why does the Sarin graphic show that the '12 o'clock' arrow shaft as dark-red opposed to dark-blue like the others? Is that a contrast or leakage issue? Could that be what i'm seeing om the comparison video? Almost, seems like the left (selected diamond) in its ''7 o'clock' shaft/facets are not reflecting too well in the diamonddock.

You can ignore that graphic; that portion of the scan is faulty. As I said above, look at the actual images. They are more reliable than scans. The ASET image shows no issues and can be trusted.

I like videos. I think they can communicate useful information. But I must repeat; they are not decisive for the minute comparisons you're attempting.

RE your question: I see what you're referring to, but the diamonds are not oriented the same way. Freeze it at 0:30 and you'll see three pavilion mains fully "on" and visible in the upper half of the left diamond. Meanwhile you see only two pavilion mains fully "on" and visible in the upper half of the right diamond. As a result of this orientation there is less "on" in the lower half of the left diamond, including the 7-o'clock area you mention. If you were to rotate the right diamond so that its upper-half was oriented precisely the same as the left's you'd see the 7-o'clock area reduced and the upper area increased.


On a side-note. It may be helpful to know that the precise positioning of the diamond dock's LED spotlights over the diamonds can influence them to react differently. This seller is experienced at making videos, and this one demonstrates equivalent lighting of the diamonds. But I've seen videos from other sources, and in alternate environments, where it's clear one diamond was more favorably positioned relative to the spotlights above.

Going farther, your eyes see in stereo, the camera sees in mono. There is no depth-perception here, which is tremendous in your perception of a diamond's total range of brilliance, fire and scintillation. More: Camera sensitivity, digital rendering and even your choice of computer monitor show contrast and brilliancy more muted than you will see it live. We can employ star-filters and processing in these videos to try and simulate depth and lifelike brilliancy to some degree, but it's just not the same as live stereo-vision. It's groovy. But not the same.

This is why I say videos are useful in general, such as "okay I definitely like the cushion more than the 60-60" or "wow both of those diamonds look fabulous." But when trying to assess the minutia we're discussing a mono-video cannot compete with human eyes, brain and cognitive perceptions. No worries, you've made a lot of headway. You've learned far more than you would in the majority of diamond showrooms (welcome to Pricescope). Now, at some point, your internet diamond quest requires a leap of faith...both in yourself and in the expert you choose to do business with.

Meanwhile, the NFL playoffs are imminent and my wife has come in to remind me several times that some thick ribeyes are waiting to be marinated... Mmm. I could take a video of them but I assure you, it won't be nearly as effective as providing them to your nose and taste-buds in-person.

Have a great Saturday.

 

[John P]

As always, John is the master of putting it all back into perspective.

Hi Christina

Thanks for the comment! Have a great weekend.

 

[Dreamer_D]

I just want to make one important point.

On the one hand, the level of detailed analysis that you are going into here is fun and interesting. The information John has provided is really educational. I am a cut geek. I love this stuff.

On another hand, in real life viewing, the level of detail you are going into here will not be apparent to your eye in my opinion. At all. I base this opinion on my many years buying and trading and buying diamonds.

So keep that clear in your mind. In person, in normal viewing, in a diamond 6.5mm in diameter, the two diamonds in that video will be utterly and completely indistinguishable. You can look into these really micro details. But you need to know you are doing that for fun and education -- for your mental pleasure and enjoyment -- and not to learn anything diagnostic about distinguishing this diamond from another AGS000, H&A diamond!

Selecting a diamond that is an AGS0, has great IS image, and good macro photo and HCA score means you have done all you can on paper. After that, you need to see it in person and let your eyes judge, and perhaps compare in person to 2-4 other flavours of cut (all similarly passing the rejection criteria) to see what your eyes guide your final selection. Your eyes are the only real selection criteria.

Just one opinion from a seasoned PSer