Evidence of Brillianteering, Echoes of Eightstar?

[Andelain]

Looking at these IS pics, what would you expect to see in the stones? I'm expecting a lot of brilliance, all the way to the edge of the stones. What do you experts think?

 

[Karl_K]

I would expect watery scintillation.
Which is why GIA would downgrade it.
It looks like enough that AGS would also.

 

[Andelain]

I would expect watery scintillation.
Which is why GIA would downgrade it.
It looks like enough that AGS would also.

Can you explain when you say watery scintilation?

These stones are actually AGS0.

 

[Karl_K]

instead of sharp on/off scintillation the scintillation off the uppers kind of flows together giving the diamond a watery look when moved in some lighting.
Some people don't mind it but it drives me batty.
I agree with gia that its a downgrade, gia would give it a vg.

In my opinion:
Sometimes its a reasonable trade off when gia papered the vg does make for lower prices for someone looking to save some money if everything else is right.
The effect is less harmful to the appearance than other things that can drop a diamond to vg.

 

[Rhino]

instead of sharp on/off scintillation the scintillation off the uppers kind of flows together giving the diamond a watery look when moved in some lighting.
Some people don't mind it but it drives me batty.
I agree with gia that its a downgrade, gia would give it a vg.

That's an interesting yet accurate way to describe the visual effects of painting. IMO Helium Reports are best as they can give the gemologist precise degrees of painting (or digging) on either crown or pavilion.

 

[Andelain]

Ah, I see. That kind of describes what I see when I look at my larger Eightstar. I love the look. So you're saying you think these 2 stones will show some of that?

 

[Andelain]

instead of sharp on/off scintillation the scintillation off the uppers kind of flows together giving the diamond a watery look when moved in some lighting.
Some people don't mind it but it drives me batty.
I agree with gia that its a downgrade, gia would give it a vg.

That's an interesting yet accurate way to describe the visual effects of painting. IMO Helium Reports are best as they can give the gemologist precise degrees of painting (or digging) on either crown or pavilion.

I wish I had a heluim report on these, I'm really curious how much these girdles are painted. Or even if they're painted at all. I can't say who the vendor is, because I want both of your comments, but these are branded stones. And no, not Eightstars.

 

[Rhino]

Ah, I see. That kind of describes what I see when I look at my larger Eightstar. I love the look. So you're saying you think these 2 stones will show some of that?

Because of the variation in IS images and photographic setups I'd never make that assessment from others photography personally. It's possible but also may not be. A Helium Report done by a Helium Scanner or Sarin HD scanner would settle the question immediately.

 

[Karl_K]

Ah, I see. That kind of describes what I see when I look at my larger Eightstar. I love the look. So you're saying you think these 2 stones will show some of that?

The effect would be more noticeable in a smaller stone.
8* does try and lessen the effect somewhat with the choice of lowers and the angle combination.
They still drive me batty however.

 

[Andelain]

Ah, I see. That kind of describes what I see when I look at my larger Eightstar. I love the look. So you're saying you think these 2 stones will show some of that?

Because of the variation in IS images and photographic setups I'd never make that assessment from others photography personally. It's possible but also may not be. A Helium Report done by a Helium Scanner or Sarin HD scanner would settle the question immediately.

If only I had a Helium scanner. I can just imagine how much one of them things costs! I remeber that little L that you said was one of the tightest ones you'd seen. Beautiful stone!

Here's the ASETs is they help at all.

 

[Andelain]

Ah, I see. That kind of describes what I see when I look at my larger Eightstar. I love the look. So you're saying you think these 2 stones will show some of that?

The effect would be more noticeable in a smaller stone.
8* does try and lessen the effect somewhat with the choice of lowers and the angle combination.
They still drive me batty however.

I knew you hated Eightstars from your past posts. I have 2, and the rippy effect seems more noticeable in my larger one, which is 1.57 ct.

I'm really curious about how it might affect these, they're 43 points each. They're also E's.

 

[John P]

From the images you posted I suspect the top diamond would not be penalized at GIA (less than 1 degree ACP). The second diamond is more on the border, with around 4-5 degrees, which could potentially become VG. Additionally, it appears painted to 'chase-out' inclusions at 3,5,6,7,10:00. This is a guess, but based on experience and presuming your ASET cone is properly oriented with the diamond girdle.

Questions that need to have decisive answers - to know if it would be penalized at GIA:

* Are we seeing crown-only painting?
* What specific average degree? GIA permits (avg) deviation from normal indexing by a bit over 4 degrees.
* What are the other proportions?

The last question relates more to the AGS 0 rating, as slight crown painting in some deeper combos improves light performance scores.


Technically, painting & digging implications correlate to 'clicks' on a diamond cutter's tang. 1 click is equivalent to 3.75 degrees. Three clicks, or 11.25 degrees, is maximum. Most ACP in high performing diamonds is limited to under 8 degrees.

These corresponding images and grades may be useful.


The reason ASET is more helpful than IS for P&D: It clearly shows how angular spectrum in a diamond changes with severity.


From this article:
http://www.pricescope.com/journal/visible_effects_painting_digging_superideal_diamonds

 

[Andelain]

Hmmm, interesting. Makes me wish all the more I had the info.

Her's the specs on each,


Table %: 54.6
Depth %: 61.5
Crown %: 15.4
Crown Angle: 34.2
Star %: 50.0
Pav Angle: 40.7
Pavillion %: 42.9
Lower Girdle %: 76.0
Culet: Pointed
Girdle Min-Max %: 1.4 - 4.0
Girdle: Thin To Slightly Thick Faceted


and



Table %: 54.7
Depth %: 62.0
Crown %: 15.5
Crown Angle: 34.5
Star %: 50.0
Pav Angle: 40.8
Pavillion %: 43.2
Lower Girdle %: 76.0
Culet: Pointed
Girdle Min-Max %: 1.0 - 3.3
Girdle: Thin To Medium Faceted

 

[John P]

Thank you.

The numbers confirm the near-Tolk presumption, and put these diamonds in a class that's going to be robust in either system - with a possible VG (presuming crown-only) for the 54.7-34.5-40.8 based on deviation from normal indexing. I'm sure you know, Andelain, that many of the basic numbers you have are averages of multiple measurements. A .SRN or full scan would allow a manufacturing report that would be facet-by-facet. It could tell us a bit more.

I also presume you realize how extremely "nano-tech" this conversation is?

 

[Karl_K]

my quick and dirty test in near tolks if the dots of leakage near the uppers are closed in the IS it has too much painting and or digging for me to recommend it.

 

[CanuckAB]

Newbie question: Does painting/digging have to be disclosed on a AGS/GIA certificate?

 

[John P]

Newbie question: Does painting/digging have to be disclosed on a AGS/GIA certificate?

GIA adds the comment "Cut grade affected by brillianteering" if the indexing is too far from normal for EX in their metric.

AGSL scans the specific diamond, and arrives at values for the light performance grade via ray-tracing when a Platinum report is ordered. If the indexing creates a reduction in the calculated values the light performance grade is reduced.

 

[CanuckAB]

Thanks John. There's so much to learn. I may be 70 before I feel ready to buy the diamond for my RHR.

 

[John P]

Thanks John. There's so much to learn. I may be 70 before I feel ready to buy the diamond for my RHR.

You can wave this topic off for the most part. It's why I made the "nano-tech" comment above.

Some history: Diamond cutters are smart. Years ago - before GIA even enforced a cut-grade and AGS only used averaged 2D proportions measurements - crafty cutters knew how to change the angles of the upper and lower halves during brillianteering (the final stages of polishing) in order to (1) retain weight at critical points or (2) disguise a girdle in a way that the verbal description would be improved. These tricks, involving techniques called painting or digging, were described by some as "cheating the girdle."

As I recall, Garry Holloway was among the first trade voices to identify and broadcast the notion that deleterious cheating should be penalized. Prior to 2000, these brillianteering concerns were recognized, but the discussions were limited to a sub-culture of cut-conscious folks many would call pedantic.

Fast-forward to Pricescope in the early-2000s: You can find a lot of threads discussing painting, specifically, because some companies - like Eightstar mentioned here - used a technique of upper-half painting (crown only) to bring upper-girdle-facet pairs to angles that would create larger broadfire flashes at the girdle. This was seen by many as attractive, but taken too far it can reduce brightness in some lighting conditions.

Fast-forward to AGSL and GIA in 2005-2006: AGSL introduces the 3D Light Performance metric which penalizes brillianteering when the indexing creates a reduction in performance to a certain degree. The next year GIA introduced their 2D proportion-based system, which penalizes brillianteering when the indexing-average is too far from normal.

Fast-forward to now. Most major labs (GIA, AGSL, HRD, IGI) now check and penalize what used to be called "cheating the girdle." The metrics vary. In all of them a little painting or digging to chase out inclusions is permitted, and remains a common practice in mass manufacturing, but there are standards in place to penalize deleterious specimens.

The conversations about "painting" still come up here because it's still interesting for those of us in the "pedantic" cut culture. But quite frankly, in the mainstream, it's a non-conversation. In fact, you can try walking into common jewelry stores and asking them about this topic and, with few exceptions, you'll largely get stares and question marks hovering in the air.

 

[Rhino]

Newbie question: Does painting/digging have to be disclosed on a AGS/GIA certificate?

In general almost every diamond is either painted or dug to some degree and even the most conservative labs will not disclose that information. GIA will only note it on their Reports when it does in fact impact the cut grade (as John points out) but even then do not note the degree to which it has been painted dug.

The conversations about "painting" still come up here because it's still interesting for those of us in the "pedantic" cut culture. But quite frankly, in the mainstream, it's a non-conversation. In fact, you can try walking into common jewelry stores and asking them about this topic and, with few exceptions, you'll largely get stares and question marks hovering in the air.

LOL YES.

 

[John P]

In general almost every diamond is either painted or dug to some degree and even the most conservative labs will not disclose that information. GIA will only note it on their Reports when it does in fact impact the cut grade (as John points out) but even then do not note the degree to which it has been painted dug.

I'll try to stop short of sounding like a commercial for Pricescope but, as it relates to Rhino's comment, the most cut-focused sellers here are regularly patrolling their diamonds for things - like brillianteering variance - which go far beyond the assessments of even the strictest labs.

Many jewelry professionals see all GIA EX or AGS 0 as equivalent. They don't explore whether a given diamond may be close to the "minimum threshold" of a grade, whether due to proportions, cut-inconsistency, indexing-at-large or in a few spots to chase out an inclusion or overcome graining.

Does it matter? After all, some departures are so tiny that the only thing affected is pure technical craftsmanship (that's enough for me). But other departures result in visible differences. Everything exists on a sliding scale and, all else equal, a diamond with 57-35.0-41.6 proportions will be less bright than one with 55-34.5-40.8, yet both receive the "top" cut grade. Will that matter to the average person? Maybe. Maybe not. GIA takes the position that their cut metric was designed to serve the whole planet. Of course, I find there are cut-focused people on the planet. For them, Pricescope is a nice place to find - in the spirit of my first paragraph.

One soapbox footnote: Wide/permissive cut grading seems a contradiction when compared to the color and clarity grading happening in the same room; where the top grade has an extremely strict range of tolerance and little visible variance, if any, one diamond to the next.

 

[Andelain]

Thank you.

The numbers confirm the near-Tolk presumption, and put these diamonds in a class that's going to be robust in either system - with a possible VG (presuming crown-only) for the 54.7-34.5-40.8 based on deviation from normal indexing. I'm sure you know, Andelain, that many of the basic numbers you have are averages of multiple measurements. A .SRN or full scan would allow a manufacturing report that would be facet-by-facet. It could tell us a bit more.

I also presume you realize how extremely "nano-tech" this conversation is?

Oh yes, I sure do. It's also been very informative to me. I'd like to thank all of you who posted in here, I really like learning beyond the basics of diamond cut.

The comments in here pretty much confirmed what I saw looking at the IS's and ASETs of these stone, and what the online rep said when she pulled them out for a looksee. In fact, here's what was said;

Jamie : it is a really amazing stone, super brilliant and bright. Even viewing it, you have to scrutinize pretty intensely to see it.
Me : It looks like it leans toward brilliance over fire. Am I correct?
Jamie : correct
Me : That's what I thought I was seeing. That
and the E color.......
Jamie : without the small areas around the edge you're not getting as much scintillation with the colored light return
Jamie : you're right on
Me : Tell me about it's mate, http://www.briangavindiamonds.com/diamonds/diamond-details/0.427-e-si1-round-diamond-ags-c-104065662019#!prettyPhoto[gallery2]/4/
Jamie : just a moment, let me pull it
Me : OK
Jamie : ok, this one is completely eye clean. inclusions are light/white- even at 2 inches you cannot see them. Also, super super bright
Me : Which way does it lean? Brilliance or fire?
Jamie : definitely brilliance like the other one
Me : Ooooooooooo
Me :
Jamie : they do have a slight twinge of fire,
but not like what you see with most of our Signature's.
Me : interesting. I wonder why they're different. the numbers aren't that different from my fierier ones
Jamie : discussing it with Brian right now
Jamie : there are slight difference in the brillanteering
Me : Oh?
Me : How so?
Jamie : just in the style of how it was cut on the wheel. He confirmed the star and lower girdles are all in line and everything which make it the Signature brand
Me : When you mentioned brillianteering, do you mean painting like an Eight
star? Because that's what I thought of when I looked at the IS, and why I swooned.
Jamie : he did mention it was like the old style vs new style in reference to the eightstar. But, these still have some slight areas of contrast which we have for all Signature stones
Me : You know my mouth is watering over here, I have 2 Eightstars and would have a dozen more if they weren't so damn expensive!
Jamie : well, these should be close and I'm sure at a better price!

Here's the links to the stones if you want the rest of the story.....

http://www.briangavindiamonds.com/diamonds/diamond-details/0.425-e-si1-round-diamond-ags-c-104065835014

http://www.briangavindiamonds.com/diamonds/diamond-details/0.427-e-si1-round-diamond-ags-c-104065662019



And yeah, they're coming to visit me.

 

[pyramid]

Me : You know my mouth is watering over here, I have 2 Eightstars and would have a dozen more if they weren't so damn expensive!
Jamie : well, these should be close and I'm sure at a better price!

So can people still by Eightstars then, I have never seen it mentioned here for year? Where are they
available from?

 

[Karl_K]

Me : You know my mouth is watering over here, I have 2 Eightstars and would have a dozen more if they weren't so damn expensive!
Jamie : well, these should be close and I'm sure at a better price!

So can people still by Eightstars then, I have never seen it mentioned here for year? Where are they
available from?

sorta yes and no
Another company bought out 8* and sells them under the same name:
http://www.eightstar.com

 

[pyramid]

Thanks KarlK.