Please help with ASET scan of princess

[stormtrooper]

Hello all,

This is a repost with a new title so people can quickly help, I''m hoping

.

I (along with the help of a friend) have been searching for a princess cut diamond for an engagement ring for my girlfriend for the past few months. I think I have a pretty good candidate currently, but have a couple of concerns that I hope to get some opinion on.

Here is the diamond information:
Shape: Princess
Carat: 1.32
Color: E
Clarity: VS1
Depth %: 71
Table %: 67
Crown %: 12
Girdle: M
Measurements: 6.18-5.98X4.27
Polish: Excellent
Symmetry: Excellent
Culet: None
Fluorescence: None

My concern is on the ASET scan of the diamond. As you can tell from the ASET scan, there is leakage in the center of the table. I have been told that it should not be too much of an issue because the leakage is only noticed when magnified. I just want to see what others think. I have seen a lot of ideal scope pictures, and most princess cuts do have some leakage in the center, just perhaps not this much.

Another concern that I have is the almost "inverted" light return nature of the diamond. Most ASET and ideal scope scans that I have seen tend to have relatively strong light return on and around the "rays" that trace from the center to the corners. But as noted on the ASET scan, the "rays" going from the center to the corners seems to be weaker light return while the area between the rays tend to have strong return. Is this an issue?

I''ll thank all in advance for any and all feedback!

Thanks!

 

[Regular Guy]

ST,

Surprised someone hasn''t come along already to help.

Until someone does (and this post will pop you to the top again), I might like to see some more red...but I don''t think, as Garry sometimes says...you have a train wreck. If it were me...I''d select, using this tool, among AGS0 options...but that may be taking a too conservative approach.

Hopefully, you''ll get more informed feedback.

 

[stormtrooper]

Thanks Ira.

I have searched for stones with AGS reports only...unfortunately it appears that manufactures will only send the stone to AGS when they are expecting a 0 grade, so there are not many of them out there.

I think it is ironic that when AGS spends the time and resources to come up with a grading system that would enable better performance indication of a stone, they end up perhaps loosing business because vendors are afraid of sending it to AGS because they are afraid of getting a none 0 grade.

Oh well...

 

[Garry H (Cut Nut)]

Date: 11/16/2007 8:52:08 AM
Author:stormtrooper

Hello all,

This is a repost with a new title so people can quickly help, I''m hoping

.

I (along with the help of a friend) have been searching for a princess cut diamond for an engagement ring for my girlfriend for the past few months. I think I have a pretty good candidate currently, but have a couple of concerns that I hope to get some opinion on.

Here is the diamond information:
Shape: Princess
Carat: 1.32
Color: E
Clarity: VS1
Depth %: 71
Table %: 67
Crown %: 12
Girdle: M
Measurements: 6.18-5.98X4.27
Polish: Excellent
Symmetry: Excellent
Culet: None
Fluorescence: None

My concern is on the ASET scan of the diamond. As you can tell from the ASET scan, there is leakage in the center of the table. I have been told that it should not be too much of an issue because the leakage is only noticed when magnified. I just want to see what others think. I have seen a lot of ideal scope pictures, and most princess cuts do have some leakage in the center, just perhaps not this much. one of the reasons I do not like the AGS system is they do not place enough emphasis on dark zones - this is what the leakage in the center can look like. however this one is too small to bother you, and if you rotate it the way I suggest ASET should really be used as shown in the ASET reference section on ideal-scope.com, then I suspect each eye will not see the leakage, and the result will be a pleasant confusion in your mind of dark and bright adding to contrats perception.

Another concern that I have is the almost ''inverted'' light return nature of the diamond. Most ASET and ideal scope scans that I have seen tend to have relatively strong light return on and around the ''rays'' that trace from the center to the corners. But as noted on the ASET scan, the ''rays'' going from the center to the corners seems to be weaker light return while the area between the rays tend to have strong return. Is this an issue? You could find stones with a little more red than this one, but it is at least a 9.8 out of 10, and once it is dirty, the cards all fall down anyway. Your task of finding a keeeper is accomplished if everything else is to your liking

I''ll thank all in advance for any and all feedback!

Thanks!

 

[stormtrooper]

Gary,

Thanks for clearing things up. Really appreciate it!

I think the only thing left is the girdle. It is from thin to medium. It''s going to be set in a 4 prong style e-ring, so I''m a little skittish.

Thanks!

 

[Garry H (Cut Nut)]

If it is GIA thin I would be worried

If it is AGs thin to medium it should be OK

an appraiser or insurance policy can help you further

 

[stormtrooper]

Gary,

Can you please clarify why GIA thin would be more of an issue than AGS thin?

I think I have read on the forum that GIA actually measures the thinner part of the girdle and the thin rating should be the min on the girdle.

GIA
Thin 0.12 - 0.15 mm
Medium 0.15 - 0.20 mm

AGS
Thin 0.51 - 1.2%
Medium 1.21 - 1.7%

That is what I got from a previous post. Not sure how those numbers correlate.

Thanks!

 

[Garry H (Cut Nut)]

Re - missed it earlier
Another concern that I have is the almost "inverted" light return nature of the diamond. Most ASET and ideal scope scans that I have seen tend to have relatively strong light return on and around the "rays" that trace from the center to the corners. But as noted on the ASET scan, the "rays" going from the center to the corners seems to be weaker light return while the area between the rays tend to have strong return. Is this an issue?

There are definitely different patterns.
Some have a more even sparkle across the stone, and others have more intense sections, with big red or blue diagonal features in the ASET.
Which is best?
I do not know. It can be personal taste - the corner to corner flashes will probably make the stone appear larger and squarer. The less intense version you posted probably has more of a pinfire appearance.

Either way - we are talking about the taste now. When you see regular parcels of goods from Israel and India, as I do, I have very high ideal-scope rejections, and then the stones that pass the ideal-scope - about half those get rejected with the ideal-scope: Why?

A few are rejected because of bad symmetry of patterns, although it has to be pretty bad to actually make avisual difference.

A few are rejected for having too much green, especially near the edges, and not enough red and blue (These ones can look super in GIA''s Diamond Dock when viewed from the way they conducted their round brilliant survey)

A few are rejected because when they are tilted, they show large leakage zones near the table edge. These generally have big tables.



BTW

Date: 11/17/2007 10:59:57 AM
Author: stormtrooper

Gary,

Can you please clarify why GIA thin would be more of an issue than AGS thin?

I think I have read on the forum that GIA actually measures the thinner part of the girdle and the thin rating should be the min on the girdle.

GIA
Thin 0.12 - 0.15 mm
Medium 0.15 - 0.20 mm

AGS
Thin 0.51 - 1.2%
Medium 1.21 - 1.7%

That is what I got from a previous post. Not sure how those numbers correlate.

Thanks!

Read http://www.adamasgem.org/cut.html#girdle
AGS now use a % rule measured at the thick part with mentions of thin, but they are always % based. A 10ct AGS medium stone has a GIA very thick girdle

 

[stormtrooper]

Thanks Gary. I am hoping to get a chance to see the stone in person next week, once I get a confirmation on the girdle, that is. I will make sure to check the performance of the stone at various tilt angles.

But on the girdle thickness, as I read the article you linked, it would seems to me that the GIA grading of thickness is better than AGS? I would think a constant thickness measurement would be better than a percent one, where the percent is dependent on the size of the diamond. But perhaps a constant percent gives better light performance?

I think my main concern is chipping of the stone. Will a GIA thin girdle rating be prone to chipping? 0.12mm seems awfully thin to me.

Thanks!

 

[Garry H (Cut Nut)]

All princess''s are many times more prone to chipping because of the diamond crystals natural cleavage direction and the fact they have 4 pointy bits.

An appraiser can help you make that choice, or ask the vendor open ended questions "if you were wearing this diamond would you insure it against chipping" etc

You seem pretty smart - I am sure you can work out what to do. You also know the wearer and have some control of the setting type.

I would not set it in a high 4 prong setting though

 

[stormtrooper]

Ok, had a chance to talk to the vendor, and they don''t seem to be too concerned about the thin girdle rating. Of course, they recommended insurance just to be sure. I did receive pictures of all 4 corners from them and as they mentioned, the difference between a thin rating and a medium rating is slight.

I think I''ll let this brew overnight and then see if I will move on it or not tomorrow.

Thanks for all the help Garry. Really appreciate it!

Here is one of the pictures of a corner.

 

[Garry H (Cut Nut)]

Date: 11/19/2007 11:42:19 PM
Author: stormtrooper

Ok, had a chance to talk to the vendor, and they don''t seem to be too concerned about the thin girdle rating. Of course, they recommended insurance just to be sure. I did receive pictures of all 4 corners from them and as they mentioned, the difference between a thin rating and a medium rating is slight.

I think I''ll let this brew overnight and then see if I will move on it or not tomorrow.

Thanks for all the help Garry. Really appreciate it!

Here is one of the pictures of a corner.

Helpful vendor

Yes, it is just thin, not knife edge.
I like to have the points polished off. But I am a bit anal.

Insure it with a good policy

 

[stormtrooper]

Ok, here is an update on the diamond searching quest and some more questions...

Got to sit down with a local appraiser and got to view the diamond in person. Just viewed it under office florescent lighting, and it seems to sparkle quite a bit (I know, don''t cringe at newbie descriptions of diamond performance). Got to review some of the features under 40x. Nothing out of the ordinary...did find out that there is a small cloud inclusion near the edge of the girdle (knew there was one, but can''t see it on the scanned copy of the grading report, only noticed it on the original). Appraiser didn''t really try to find it though...said that it will be hard to find and it won''t be visible to the eye and it probably won’t affect durability.

Appraiser also don''t seem to be too concerned about the thin-medium girdle, but did recommend V-prongs for protection of the corners and of course, insurance.

Paid a little bit more for a full 3D Sarin scan (BTW, anyone want to create a virtual gem model for me??

).

The 3D scan revealed that one side of the diamond have 4 triangle facets, but the other 3 sides only have 3. This means that the stone is only symmetric on one axis. I didn''t know GIA would still give an "excellent" grade to the symmetry if the diamond had extra triangle facets like that.

Overall it was a pleasant experience with the appraiser. I think I got most of my questions answered.

So the long winded post questions are: Anyone see any concerns with the diamond? Is it safe to proceed?

Thanks!

 

[JohnQuixote]

Date: 11/26/2007 7:47:02 PM
Author: stormtrooper

Nothing out of the ordinary...did find out that there is a small cloud inclusion near the edge of the girdle (knew there was one, but can't see it on the scanned copy of the grading report, only noticed it on the original). Appraiser didn't really try to find it though...said that it will be hard to find and it won't be visible to the eye and it probably won’t affect durability.

Did your appraiser show you the inclusions in darkfield lighting? That's my favorite part of grading.

Date: 11/26/2007 7:47:02 PM
Author: stormtrooper

Paid a little bit more for a full 3D Sarin scan (BTW, anyone want to create a virtual gem model for me??

).

The 3D scan revealed that one side of the diamond have 4 triangle facets, but the other 3 sides only have 3. This means that the stone is only symmetric on one axis. I didn't know GIA would still give an 'excellent' grade to the symmetry if the diamond had extra triangle facets like that.

It’s great that your were provided with a 3D scan.

One observation though: Non-contact scans are not always accurate, especially when reading complex shapes and slight angular changes. We have the very top of the line Sarin and even it has difficulties sometimes - though technology is constantly improving. This is why extra facets and symmetry variations are graded with the human eye under magnification during clarity and finish evaluation. Did your appraiser take zoomed photos?

 

[stebbo]

Date: 11/26/2007 7:47:02 PM
Author: stormtrooper
...
Paid a little bit more for a full 3D Sarin scan (BTW, anyone want to create a virtual gem model for me??

).
...
Thanks!

Post the Sarin and someone or I will knock one up for you.

 

[stormtrooper]

Date: 11/26/2007 8:45:59 PM
Author: JohnQuixote

Did your appraiser show you the inclusions in darkfield lighting? That''s my favorite part of grading.

Unfortunately not. Didn''t know if that could have been done...I obviously didn''t know enough to ask for that sort of grading also...

Date: 11/26/2007 8:45:59 PM
Author: JohnQuixote
It’s great that your were provided with a 3D scan.

One observation though: Non-contact scans are not always accurate, especially when reading complex shapes and slight angular changes. We have the very top of the line Sarin and even it has difficulties sometimes - though technology is constantly improving. This is why extra facets and symmetry variations are graded with the human eye under magnification during clarity and finish evaluation. Did your appraiser take zoomed photos?

Not sure if I named the facets correctly...here is a screen capture of the 3D view from sarin file.

 

[stormtrooper]

Date: 11/26/2007 9:12:13 PM
Author: stebbo

Date: 11/26/2007 7:47:02 PM
Author: stormtrooper
...
Paid a little bit more for a full 3D Sarin scan (BTW, anyone want to create a virtual gem model for me??

).
...
Thanks!

Post the Sarin and someone or I will knock one up for you.

Thanks Stebbo!

What information do I need to post? I can''t post *.srn files. Extension is not allowed.

 

[Garry H (Cut Nut)]

You should be able to save it - you might need to give the rest of it a very distinctive name.

Or email it to me - I am not that hard to find

 

[Paul-Antwerp]

Date: 11/26/2007 8:45:59 PM
Author: JohnQuixote

Date: 11/26/2007 7:47:02 PM
Author: stormtrooper

Paid a little bit more for a full 3D Sarin scan (BTW, anyone want to create a virtual gem model for me??

).

The 3D scan revealed that one side of the diamond have 4 triangle facets, but the other 3 sides only have 3. This means that the stone is only symmetric on one axis. I didn''t know GIA would still give an ''excellent'' grade to the symmetry if the diamond had extra triangle facets like that.

It’s great that your were provided with a 3D scan.

One observation though: Non-contact scans are not always accurate, especially when reading complex shapes and slight angular changes. We have the very top of the line Sarin and even it has difficulties sometimes - though technology is constantly improving. This is why extra facets and symmetry variations are graded with the human eye under magnification during clarity and finish evaluation. Did your appraiser take zoomed photos?

Very true, John, that Sarins have a serious difficulty in scanning parts of fancy shapes. We found it to show constant errors in the crown area of princess-cuts.

In the pavilion-area however, they generally are rather correct. In this case, I think it is very clear that one side has 4 chevron-facets, while the other sides have only 3. This is a very common practice in commercially produced princess-cuts, and I am not surprised to see this. One can also easily verify this with a loupe.

Unfortunately, it is not part of symmetry-grading in a lab. I am not even sure that it is downgraded within AGS-symmetry-grading. However, it creates an optical asymmetry, and I personally do not like this at all. But we will probably have to await the results of some scientific study on scintillation, in order to truly appreciate the value of optical symmetry.

Live long,

 

[stebbo]

Date: 11/26/2007 9:31:18 PM
Author: stormtrooper

Thanks Stebbo!

What information do I need to post? I can''t post *.srn files. Extension is not allowed.

Yeah, you''re right. Maybe Andrey can enable srn if he''s reading.

In the meantime, change the file extension to .gem to bypass the ban if you haven''t found Garry''s email.

 

[stormtrooper]

Date: 11/27/2007 5:41:00 AM
Author: stebbo

Yeah, you''re right. Maybe Andrey can enable srn if he''s reading.

In the meantime, change the file extension to .gem to bypass the ban if you haven''t found Garry''s email.

Thanks Stebbo.

I have attatched the renamed (from SRN to GEM) file in this message.

I think I found Garry''s e-mail...so I mailed it to Gary also.

Thanks for the help!

 

[psadmin]

Hi Guys,

The sarin extension is now enabled.

let me know if you guys find any difficulties with it.

Andrey
PS Admin

 

[stebbo]

Attached.

 

[JohnQuixote]

Date: 11/27/2007 3:56:05 AM
Author: Paul-Antwerp

Very true, John, that Sarins have a serious difficulty in scanning parts of fancy shapes. We found it to show constant errors in the crown area of princess-cuts.

In the pavilion-area however, they generally are rather correct. In this case, I think it is very clear that one side has 4 chevron-facets, while the other sides have only 3. This is a very common practice in commercially produced princess-cuts, and I am not surprised to see this. One can also easily verify this with a loupe.

Unfortunately, it is not part of symmetry-grading in a lab. I am not even sure that it is downgraded within AGS-symmetry-grading. However, it creates an optical asymmetry, and I personally do not like this at all. But we will probably have to await the results of some scientific study on scintillation, in order to truly appreciate the value of optical symmetry.

Live long,

In the big picture I agree. Labs approach this much the same way as they do “superideal” versus “ideal” in rounds, making no distinctions. In the future the lab we feel is most likely to develop criteria for OS will be the AGSL (our opinion anyway).

I had something different in mind when Stormtrooper referred to extra facets. Also, I’m still not convinced to trust a scan over actual inspection. We have a photo looking through the crown of this diamond. No pavilion photo (Stormtrooper, any chance?). What we see through the table is nice symmetry in each quadrant. What do you think, Paul?

 

[Paul-Antwerp]

I have to agree with you, John, up to a certain level.

When we look at the side-view of one of the corners in a previous post, you can see that there are 4 chevron-lines on both sides of that corner.

Live long,

 

[JohnQuixote]

I forgot we took those photos Paul.

In fact, there are four chevrons on all corners. See below. Photo C is not clear, but the others are. So, where the scan diagram shows 3-chevrons on 3 sides it's actually a 4-chevron stone. It is possible to select different crown-pavilion combinations in the scanning software during setup which may have been the issue here?

As for uniformity; the photos show seven out of eight positions matching. The left side of photo C is unclear but by deduction we’re inclined to think the last one matches too... We may be wrong of course, as we don’t have the stone in front of us. Stormtrooper you may be able to make your own assessment with a loupe?

 

[JohnQuixote]

I put the scan diagram (with colored-in mains) next to the 40X photo. We’re seeing the pavilion through the table in the actual photo so it''s not definitive, but this further implies that the actual stone has consistent chevrons while the scan diagram does not.

In any case Stormtrooper, this minutia makes no difference in the beauty of the stone, which you have in your hands. We’re happy to investigate though, and hope this is helpful.

 

[stormtrooper]

Date: 11/27/2007 5:37:15 PM
Author: JohnQuixote
I put the scan diagram (with colored-in mains) next to the 40X photo. We’re seeing the pavilion through the table in the actual photo so it''s not definitive, but this further implies that the actual stone has consistent chevrons while the scan diagram does not.

In any case Stormtrooper, this minutia makes no difference in the beauty of the stone, which you have in your hands. We’re happy to investigate though, and hope this is helpful.

John,

Actually, the stone is on its way back to WF to be mounted. I also just spoke to Jamie and informed her to move forward with the purchase.

Thanks for looking into the extra facet issue...it does appear that the scan is in error. Interesting to note that the scan has all the facets with somewhat wide ranging angles (no 2 are close to indicate a simple miss scan). Perhaps you can snap a quick picture of the pavilion before it gets mounted to confirm.

And please thank Jamie for me...she has been putting up with me for the past couple of months. She probably will need a vacation after this is over

 

[stormtrooper]

Date: 11/27/2007 10:12:01 AM
Author: stebbo
Attached.

Thanks Stebbo!

Garry sent me a model also.

I am grateful for all the help from everyone. There is no way I would have made such a purchase online without this forum...

...I''m starting to think of mischievous things that I can do with the animation of the virtual gem...

Thanks all!!

 

[stormtrooper]

Folks,

Due to the wonderful help that I received from this community, I am now engaged!

Fiance loves the ring. She can''t stop waving it in front of me for some reason...

Thanks all that help! It is greatly appreciated!