GIA FacetScan question for peers

[Rhino]

Greetings fellow tradesmen,

If you happen to be reading while out here at Symposium.....

On Saturday while I was registering I happened to catch some of the things being setup and in particular the new GIA FacetScan non contact measuring device. I also noted that it does happen to be an OGI single lens system except apparently this one is built from the ground up to work off of Windows XP and off of USB 2.0 (ie. you don't need additional pci cards etc.) and it will work off of any Windows XP based computer. GIA is helping to guide the software construction to help make it more user friendly to the trade. A definite step in the right direction I think. While the OGI technician was setting up the scanner I was talking to them about the quality of the models produced by the scanner and apparently there are 2 settings. One being "standard" the other being "professional". The latter being a more lab oriented version which interested me.

2 questions I have for some of my peers who happen to be reading. Garry or Sergey, your input would be appreciated if you are.

1. It was claimed during this short meeting that the OGI scans at 400 steps/scans while the Sarin only does 160. I have no reason to doubt OGI's claim of 400 steps/scans but Garry, I know you represented Sarin at one time or perhaps still do. Do you know if this is true regarding the amount of scans/steps the Sarin DiaMension does? I always thought the Sarin scanned at least 400 steps and know that in their newer DiaVision software there are 2 settings. One for quick scans and another for slower scans at higher resolution. I've always been able to produce more accurate models with with Sarin DiaMension. Just curious if you knew how many steps/scans the Sarin DiaMension takes in its analysis?

2. Based on my experience with non contact measuring devices one of the most challenging types of diamonds for a scanner to see happens to be one with painted upper halves. It is tough for many of these scanners to resolve those facets. Garry ... do you or does anyone here have a stone in CA with painted upper halves to run on the FacetScan to test its abilities to resolve those facets?

Thanks in advance for your input.

BTW, the new OGI software DOES look very cool with lots of options, reports, web capabilities etc. but I'm just wondering if they've improved its capabilities to produce more accurate models. There's even a quick button to produce an .stl file to load into AGS PGS software.

All the best,

 

[Garry H (Cut Nut)]

I have heard good things about it too - but have not been able to test it yet Rhino.

 

[Serg]

Tests and photos on GIA Instrument booth are allowed but not for every participant of the GIA symposium.

 

[Rhino]

Thanks for the input guys. After talking with the OGI rep we''ll be getting upgraded software either during or after the show. Once we do I have stones at the store with varying degrees of girdle cutting which I''ll be testing the model making capabilities with. If you''re interested I can post the comparisons here or in email. I also got the answers I was looking for regarding the step/scans on the Sarin. In the DiaVision software which we''ve been using the DiaMension will either scan at 100 steps (fast scan) or 400 steps (slower and more accurate). I made sure the reps got it straight.

 

[Garry H (Cut Nut)]

People I know who have tested the GIA say that it was very bad at builing models, but Ogi are working to improve it and things look good.
Accuracy of painting recognition is stilll somewhat in question - but for the money it seems like a great package (free microscope and steak knives too).

The Ogi rep is Daniel - he is not the rep Rhino, he is Ogi. Nice straight forward guy - more Aussie than Israeli.

And the Sarin rep is thier chief programmer and IT developer - Avi - also a very nice and knowledgable guy. I have a lot of time for him.

All in all it is good that there are easier to use and more affordable options for many appraisers and retailers: but as Sergey would say - "for us it is not interesting"

 

[Rhino]

Understood. Yea I know Dani but I understand he is not here. Can''t recall the name of the dude who is here representing OGI but was talking with him and some of the GIA reps today and on Saturday when they were setting it all up.

Garry, it was a pleasure to see you and introduce you to my wife. It was also a great pleasure to finally meet Sergey and Yuri in person. As you typed out what you''d expect Sergey to say I can just hear him saying it exactly as you typed it, accent and all. How did you guys meet initially? If you like we can pick this up in email.

All the best,

 

[adamasgem]

Date: 8/28/2006 10:01:38 AM
Author: Serg
Tests and photos on GIA Instrument booth are allowed but not for every participant of the GIA symposium.

Hi Sergey..
I guess you were one that were not allowed

It will be interesting to compare the accuracy issues on the new scanner...

What is GIA charging for their scanner?

It will also be interesting, as Johnathon said, is their capability of scanning painted crown halfs..
All the Sarin scan I've seen on these type of stones are not very good, and Johnathon showed one from OGI which was pure junk..
The GIA scanner is probably the same thing with "accuracy" matching the Farceware rounding scheme.
.
One of the issues is how they (Sarin GIA, etc) handle bruted girdles as to constructing a series of planes to mimic the bruted girdle...

Ray tracing these type of stones is not very difficult to simulate, all you do is create a random angle of incidence/reflection when you hit the girdle instead of following the normal angle of incidence/reflection rulles.

As to the rest of Farceware(TM), I don't seeing it as a usefull tool at all..

I didn't go to the GIA symposium becuase I couldn't find my bullet proof vest.

 

[Serg]

re:Hi Sergey..
I guess you were one that were not allowed

Hi Marty

Yes. And Garry, Leonid, Yurii are not allowed too. I do not know about other

 

[denverappraiser]

Date: 8/29/2006 10:27:28 AM
Author: Serg
re:Hi Sergey..
I guess you were one that were not allowed

Hi Marty

Yes. And Garry, Leonid, Yurii are not allowed too. I do not know about other

This sounds like a badge of honor. You should be proud to be included in such good company.

I wish I was there, maybe I would get to be excluded too.

Surely they can't imagine that they can preserve a visible trade secret while exhibiting at a trade show by excluding a few famous critics. Spys are everywhere

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[adamasgem]

Date: 8/29/2006 10:27:28 AM
Author: Serg
re:Hi Sergey..
I guess you were one that were not allowed

Hi Marty

Yes. And Garry, Leonid, Yurii are not allowed too. I do not know about other

Maybe the omnipotent KING isn''t wearing any clothes and doesn''t want anyone to notice..

Sounds really like a top notch educational tax exempt institution..

You pay your conference fees and they exclude you from looking at their "latest and greatest" technology. GIA Voodoo for jewelers..

Looks like FarceWareScan(TM) will eventually join the ranks of FarceWare(TM) and Kittydock(TM).

Just don''t drink the GIA Koolaid

 

[adamasgem]

Date: 8/29/2006 10:27:28 AM
Author: Serg
re:Hi Sergey..
I guess you were one that were not allowed

Hi Marty

Yes. And Garry, Leonid, Yurii are not allowed too. I do not know about other

I figured it out from Boston, they didn''t want you to notice their latest grading improvement, consistent with the rest of their 100 million dollar a year operation

Rubber Yardsticks..

 

[CaptAubrey]

Photography and videotaping were not permitted at the symposium, I think because there was a company that had contracted to videotape the sessions and sell the tapes. There was a statement to that effect in the registration materials. I don''t think anyone was singled out.

 

[pricescope]

Here is the Registration Form that we signed at registration. Captain, could you please point me to any mention about video recordings or interviews during the event?

 

[Garry H (Cut Nut)]

Date: 8/30/2006 1:32:13 PM
Author: CaptAubrey
Photography and videotaping were not permitted at the symposium, I think because there was a company that had contracted to videotape the sessions and sell the tapes. There was a statement to that effect in the registration materials. I don't think anyone was singled out.

Two days after the event noted above, Leonid and I were interrupted while interviewing the CEO of the Jewelrs Vigilance Council inside one of the poster area in my booth, and later on, stopped from interviewing one of the directors of IGI in a public zone within the hotel. Perhaps you can show us in Leonids post above where we signed a release stating that we would not interview people at the Symposium? Frankly we were stunned.

Infact we had filmed a day or 2 before and made no attempt to be secretive or sneaky because we imagined that GIA would welcome the stories and threads pertaining to presenting the "human faces behind the people and organizations" which was our overall theme.

The GIA person in charge of the Poster presentation (who interrupted us) was sitting directly infront of Leonid and I at the opening concert / performance, and she told Leonid he could not record anything because he was putting his tripod up. He told her it was a still camera and she said "that is OK then". I pointed out the huge video camera in the bag on the floor to her and said "if he was going to record it he would use the video camera". She made no mention of any restrictions on using the video camera at other times - until she saw us 2 days later in her Poster area. Since I was asking questions while Leonid was filming it was naturally convenient that we do it at the poster area - as I was asked to attend the poster area during breaks - and that was the only time most of the people who wanted to be interviewed found convenient too.

We had even asked permission to interview one of the GIA Cut Study Team, who seemed quite keen on the idea. We asked permission to interview the cut person at a very high level, the new President Donna Baker was even CC’d and acknowledged receipt of my email.

Another GIA person thought it would be a good idea if we interviewed him and gave him the tape so he could clear it after GIA had cleared and released the story.

At no stage were we aiming to be anti GIA (other than things to do with the Diamond Dock(r) ) - they are a great org doing a huge amount of great work. In fact we can see that our DD message is getting through to some of their people. And if there was some fine tuning done to their grading and training systems as a result of our efforts then the entire scientific peer review method would indeed be alive and well.

I asked my secretary by SMS text message and she could find no mention on the registration forms about videoing or recording. They told us during presentations, and I think that it was also in the program - but the only mention was that we should not video or record any presentations - but still photography was OK. Video restrictions - if there were any seem to be very hard to find? Video interviews inside the poster regions? Outside areas specifically rented and paid for by GIA?

BTW we were not videoing, two days earlier, when one of the GIA's Directors (in a raised voice in ear shot of about a dozen people) threatened to call security and have us removed. We were simply taking photo’s of Sergey’s colored CZ’s inside Diamond Dock® - that some of you have seen these CZ’s on threads here. It was a scientific experiment to show the effects of strong lights close up to stones, vs ambient light. This was a genuine scienfic study at a real live scientific research conference.

 

[CaptAubrey]

Date: 8/30/2006 9:27:58 PM
Author: Pricescope
Here is the Registration Form that we signed at registration. Captain, could you please point me to any mention about video recordings or interviews during the event?

No, obviously there's nothing on the registration form, but I do recall seeing something to that effect in the program--which I cannot find at the moment. But, definitely there was something there. And I do recall a mention being made at some point of the fact that recordings were being made for sale afterward. That's about all I can tell you.

 

[adamasgem]

Date: 8/30/2006 9:44:31 PM
Author: Garry H (Cut Nut)


BTW we were not videoing, two days earlier, when one of the GIA''s Directors (in a raised voice in ear shot of about a dozen people) threatened to call security and have us removed. We were simply taking photo’s of Sergey’s colored CZ’s inside Diamond Dock® - that some of you have seen these CZ’s on threads here. It was a scientific experiment to show the effects of strong lights close up to stones, vs ambient light. This was a genuine scienfic study at a real live scientific research conference.

You missed a golden opportunity to make a lot of money with the ensuing lawsuit.

I would have "politely" told him/her to "try it and I''ll own everything you have".

I''m sure that the GIA board would have appreciated in the negative publicity

generated by that observant and overly protective board member, who probably sufffers from a lack of common sense and probably a severe case of rectal-cranial inversion.

 

[Garry H (Cut Nut)]

Marty I said a director, not a board member. And have you ever been aware of me having or showing any interest in lawyers other than patent attorneys?

CaptA - other than Martin Rapaport on the topic of fair trade development diamonds, I do not believe we spoke to anyone on any of the topics they presented on or about. We are simply not that rude or naive or out to make enemies - to the contrary - we (naively?) assumed that GIA would be jubilant about the way that we would have been able to present information about the industry leaders we interviewed (and planned to interview before the rug was pulled out).

Imagine now we must contact all these people and tell them that we are so sorry we wasted their time?

 

[adamasgem]

Date: 8/31/2006 2:51:55 AM
Author: Garry H (Cut Nut)
Marty I said a director, not a board member. And have you ever been aware of me having or showing any interest in lawyers other than patent attorneys?

I stand corrected

Speaking of patent attorneys

I know a decent litigator..

 

[adamasgem]

Date: 8/31/2006 2:51:55 AM
Author: Garry H (Cut Nut)
CaptA - other than Martin Rapaport on the topic of fair trade development diamonds, I do not believe we spoke to anyone on any of the topics they presented on or about. We are simply not that rude or naive or out to make enemies - to the contrary - we (naively?) assumed that GIA would be jubilant about the way that we would have been able to present information about the industry leaders we interviewed (and planned to interview before the rug was pulled out).

Imagine now we must contact all these people and tell them that we are so sorry we wasted their time?

So now you learned what omnipotence is about..

 

[Rhino]

Date: 8/30/2006 11:44:52 PM
Author: CaptAubrey

Date: 8/30/2006 9:27:58 PM
Author: Pricescope
Here is the Registration Form that we signed at registration. Captain, could you please point me to any mention about video recordings or interviews during the event?

No, obviously there's nothing on the registration form, but I do recall seeing something to that effect in the program--which I cannot find at the moment. But, definitely there was something there. And I do recall a mention being made at some point of the fact that recordings were being made for sale afterward. That's about all I can tell you.

I recall reading about this too Capt. I had my video cam with me and wanted to record a presentation particularly "The Great Internet Debate" Leonid and I were panel members of and some stuff on the display floor. The announcements were clear in the presentation rooms and I was asked politely not to video tape on the showroom floor so I didn't pursue it. I didn't view it as a big whoop particularly because the gentlemen on the showroom floor were extremely cooperative and helpful in answering all my questions and even taking suggestions & constructive criticisms from me on how to improve products they had I was familiar with. The OGI rep (Avi was his name) and the GIA reps demonstrating the FacetScan (Robin and Howard) listened to my input and noted changes I was suggesting in the software to make it a little more user friendly and were very interested in my input. I respected their open mindedness and they even gave me the most updated versions of the software upon my request right there at the show.

Garry, did you at least view the stones you wanted to under the DiamondDock to better understand their perspective and why they chose it as the CVE?

Regards,

 

[Garry H (Cut Nut)]

Exactly Rhino. We did none of those things with our video camera.

And yes, I was not able to see the 2 diamonds in Diamond Dock on the showroom floor - but both the GIA instructors who looked at the stones picked the shallow VG near Good one for brightness over the Tolkowsky in Diamond Dock, and one picked it for fire also which amazed me.

As with your experiance we think they now understand the short comings in their method. I am glad you had similar experiances.

And yes - you were right Rhino - in their new Cut training classes they now recomend using Diamond doack from the highest possible viewing angle to get the est results. As you can imagine being an owner of DD, and being experianced with colored reflectors, this of course means that most of the data from the 70,000 observations is the reason that we can hope they will change the Facetware data base to bring the center points of their Excellent grades back around Tolkowsky.

 

[adamasgem]

Date: 8/31/2006 10:23:55 AM
Author: Garry H (Cut Nut)
And yes, I was not able to see the 2 diamonds in Diamond Dock on the showroom floor - but both the GIA instructors who looked at the stones picked the shallow VG near Good one for brightness over the Tolkowsky in Diamond Dock, and one picked it for fire also which amazed me.

As with your experiance we think they now understand the short comings in their method. I am glad you had similar experiances.

And yes - you were right Rhino - in their new Cut training classes they now recomend using Diamond doack from the highest possible viewing angle to get the est results. As you can imagine being an owner of DD, and being experianced with colored reflectors, this of course means that most of the data from the 70,000 observations is the reason that we can hope they will change the Facetware data base to bring the center points of their Excellent grades back around Tolkowsky.

When I participated (in Tuscon) with their "brilliance" comparison study, which appeared to me at the time, to be fairly well designed with apparent multiple looks at the same stone mixed up with other stones, we did it in a portable booth (not the KittyDock(TM)). [ Comparisons were like A:B , B:C, A:C, C, B etc] It appeared to be a decently designed rank correlation study, with the exception that every viewer had a different look angle depending on how he/she would tilt the stone, or his/her physical stature. Back lighting was also an issue, but we did put on white lab coats.. We were doing it sitting down at a table with the tray at table height.

From your post, I am unclear on what they are doing. Stand up to grade??? Redesign the KittyDock(TM)? Start all over? Initiate a recall on all paper???

Please enlighten us...

 

[Garry H (Cut Nut)]

Date: 8/31/2006 1:34:34 PM
Author: adamasgem

When I participated (in Tuscon) with their ''brilliance'' comparison study, which appeared to me at the time, to be fairly well designed with apparent multiple looks at the same stone mixed up with other stones, we did it in a portable booth (not the KittyDock(TM)). [ Comparisons were like A:B , B:C, A:C, C, B etc] It appeared to be a decently designed rank correlation study, with the exception that every viewer had a different look angle depending on how he/she would tilt the stone, or his/her physical stature. Back lighting was also an issue, but we did put on white lab coats.. We were doing it sitting down at a table with the tray at table height.

From your post, I am unclear on what they are doing. Stand up to grade??? Redesign the KittyDock(TM)? Start all over? Initiate a recall on all paper???

Please enlighten us...

Marty if you look at the image in my first post in the FAQ thread here https://www.pricescope.com/community/threads/gia-diamond-dock-simple-summary.42538/ - one of the instructors used the highest possible angle - about the 70 on this graphic - the other used about the 75 degree position. The first also found the shallow painted stone to be more firey than the Tolkowsky. Both found the shallow brighter. The stones are the very same stones that I used in that DD article that the thread links to.

And then scroll down to where I posted the the Diamond Dock(r) manual photo''s supplied by Rhino. I imagine that you were viewing from more like a 45 degree angle - although because of your height it may have been more like 50-55 degrees?

If the majority of the observations were made at 45 to 50 degrees then I am sure you could demonstarte with your software (as AGS have) that most observers would have preferred deeper proportion sets.

 

[adamasgem]

Date: 8/31/2006 1:55:10 PM
Author: Garry H (Cut Nut)

Marty if you look at the image in my first post in the FAQ thread here https://www.pricescope.com/community/threads/gia-diamond-dock-simple-summary.42538/ - one of the instructors used the highest possible angle - about the 70 on this graphic - the other used about the 75 degree position. The first also found the shallow painted stone to be more firey than the Tolkowsky. Both found the shallow brighter. The stones are the very same stones that I used in that DD article that the thread links to.

And then scroll down to where I posted the the Diamond Dock(r) manual photo's supplied by Rhino. I imagine that you were viewing from more like a 45 degree angle - although because of your height it may have been more like 50-55 degrees?

If the majority of the observations were made at 45 to 50 degrees then I am sure you could demonstarte with your software (as AGS have) that most observers would have preferred deeper proportion sets.

I don't think the "problem" is necessarily viewing angle..
It is viewing distance

1) GIA's dome studies were done at 3, 6 and 8 inch viewing distances (1/2 dome diameter) (Unaffected by head shadow)

2) AGS uses a "normal" 10 inch visual accomodation distance

3) In their new Diamond Grading Lab Manual, GIA SHOWS viewers at the 18 to 20 inch estimated range

4) In their new Diamond Grading Lab Manual, GIA "recommends" a viewing distance of 12 to 18 inches, inconsistent with their dome studies..

5) In their fall 2004 G&G article, they said they modeled a "localized observer" viewing from 14 to 20 inches who only "detected light from within a narrow - 3 degree angular spread - area", Their Figure 10 is ambiguous.

6) In their Fall 2004 article, GIA implies their brightness metric was based on a "hemisphere" with a 3 degree viewing window, 46 degree "head shadow", but I can't find where they specified the viewing distance, i.e. 1/2 the diameter of the "dome"

The closer you get to the stone in the KittyDock(TM) (and consequently the primary light source):

a) The wider the "acceptance angle" becomes for rays exiting the stone, the larger the stone appears in your field of view, and consequently the more total energy is available to your eye

b) The larger your head "shadow" from any backlighting

c) The stronger the intensity of the reflected light from your face (comment does not apply to the dome studies, and consequently the more energy entering the stone from highangle lighting

d) As you move closer to the reflections from the KittyDock(TM), the smaller the pupil diameter may become

e) The more "visible" "pinfire" becomes and maybe the less distiction between "broadflash" and "pinfire" fire


I think these may be the primary problems with case a) probably accounting for the vast differences in "preferences"...

Case 6) above may be technically ambiguous

 

[Garry H (Cut Nut)]

They may be additional factors Marty, but I can now select lighting types where observers will prefer the shallow stone over the deep - and this angular lighting / diamond observer difference is the main variable. Trust me mate - it has become quite predictable.

BTW I am not suggesting the shallow stone is better than the tolkwsky - I am using it to predict and display the primary problem that skewed the GIA human observer testing that you and others participated in.

I agree that there are other problems (including back ground eye adaption to the bright lighting from the 18% grey tray and DD shade) - but my investigations so far lead me to conclude the main issue is the narrow and specific angle of light to diamond to observer.

This graphic from the AGS article presented in the Optics and Photonics Journal April 2003 was possibly something you worked on? It led to the selection of the 45 degree point as the red green boundary on the ASET scope. Shallower stones gather more light toward the 90 degree right side (directly over head) and deeper stones gather a relatively larger amount of light from the left side of the chart - closer to the 45 degree / horizon

 

[Serg]

Date: 8/30/2006 11:44:52 PM
Author: CaptAubrey

Date: 8/30/2006 9:27:58 PM
Author: Pricescope
Here is the Registration Form that we signed at registration. Captain, could you please point me to any mention about video recordings or interviews during the event?

No, obviously there's nothing on the registration form, but I do recall seeing something to that effect in the program--which I cannot find at the moment. But, definitely there was something there. And I do recall a mention being made at some point of the fact that recordings were being made for sale afterward. That's about all I can tell you.

re: "But, definitely there was something there."


It is not enough. Please give full link.

re:
"And I do recall a mention being made at some point of the fact that recordings were being made for sale afterward."

What are recording exactly for sale? What is connection with Leonid interview or our photos? Was anybody buy exclusive permission for interview during Symposium?

BTW. Why did GIA sell permission for sells video my report? I did not sell such permission to GIA!

 

[Serg]

re:BTW. Why did GIA sell permission for sells video my report? I did not sell such permission to GIA!


I am speaking about reports on Research conference( Not for Symposium)

 

[adamasgem]

Date: 9/1/2006 6:15:35 AM
Author: Serg


re: ''But, definitely there was something there.''

It is not enough. Please give full link.

re:
''And I do recall a mention being made at some point of the fact that recordings were being made for sale afterward.''

What are recording exactly for sale? What is connection with Leonid interview or our photos? Was anybody buy exclusive permission for interview during Symposium?

BTW. Why did GIA sell permission for sells video my report? I did not sell such permission to GIA!

You probably didn''t read the GIA legaleeeeese in what was in the microdot embedded in the first "i" of "Registration"

 

[adamasgem]

Date: 8/31/2006 4:04:04 PM
Author: Garry H (Cut Nut)
They may be additional factors Marty, but I can now select lighting types where observers will prefer the shallow stone over the deep - and this angular lighting / diamond observer difference is the main variable. Trust me mate - it has become quite predictable.

BTW I am not suggesting the shallow stone is better than the tolkwsky - I am using it to predict and display the primary problem that skewed the GIA human observer testing that you and others participated in.

Garry.. I know what you are talking about, in that higher angle lighting gives you more "discrimination" between stones, but not necessarily a overall measure of "goodness".

I showed this a couple of years back on that long thread with Sergey where we discussed and compared WLR results and chromatic flares. As you increased the angular spread of lighting from the zenith, all the WLR values mushed together and the relative WLR metric from one cut to another changed.

It is just that the viewing distance related relative metrics have not been presented anywhere to my knowledge. Since the "collection cone" changes so dramatically as you move in toward the stone, it may have more influence than one would think on perception of relative brightness..

 

[Rhino]

Date: 8/31/2006 10:23:55 AM
Author: Garry H (Cut Nut)
Exactly Rhino. We did none of those things with our video camera.

And yes, I was not able to see the 2 diamonds in Diamond Dock on the showroom floor - but both the GIA instructors who looked at the stones picked the shallow VG near Good one for brightness over the Tolkowsky in Diamond Dock, and one picked it for fire also which amazed me.

As with your experiance we think they now understand the short comings in their method. I am glad you had similar experiances.

And yes - you were right Rhino - in their new Cut training classes they now recomend using Diamond doack from the highest possible viewing angle to get the est results. As you can imagine being an owner of DD, and being experianced with colored reflectors, this of course means that most of the data from the 70,000 observations is the reason that we can hope they will change the Facetware data base to bring the center points of their Excellent grades back around Tolkowsky.

Thank you for the acknowledgment Garry.

Finally back up at work today after it all.

This was one trip I didn''t look forward to coming home from. I coulda used another week in San Diego and overall this has been one tremendous show me thinks. My only regret was not being able to spend more time with you, Leo and gang.

From what I have learned I don''t think GIA is concerned about center points on the FacetWare perse because the Ex grade does encompass quite a few different appearances which appeal to different personality types. Ie. I''ve been showing 2 Ex''s alongside each other in the recent future where the only differences are lower half length slightly altering brightness and moreso the nature of their scintillation and some folks prefer one, some the other with no dead heat on a winner in our surveys.

Interestingly while I was writing our new cut tutorial for the website last year one of the stones I used as an example there is of a former AGS Ideal which now doesn''t make AGS Ideal but would make GIA Ex. I discuss 2 different kinds of a *brightness* factor I was observing in the 2 which I had described at that time as "brightness because of contrast" and "brightness at the expense of contrast". I believe I still have that stone here too. I see a new survey coming.

Also would it be possible to get the .dmc files from the 2 diamonds Leonid inverviewed John and I with? I am very curious to know their specs.

Thanks in advance,