Is there a way to tell if this GIA EX would qualify as an AGS000?

[sslkrissi]

Hello,
I have just read a bunch of threads which discuss how GIA is much less strict in their grading standards than AGS is. So, my question is... is there any chart or calculator that I can enter the specs of this stone in to find out of it would be considered an AGS000? When I enter the info into the HCA, it comes out as a 1.6 which is clearly within the area outlined for an AGS ideal candidate. Is that sufficient?

The specs are listed in this previous post: https://www.pricescope.com/community/threads/please-help-is-there-any-reason-not-to-buy-this-diamond.81605/

Thanks

 

[honey22]

Yep, the HCA is what you are looking for. If it falls into the white box (not dotted lines, these are GIA) it will be AGS Ideal.

ETA - I just had a think (sorry, bad headcold today and not totally with it

)

It will be AGS Ideal cut wise, but I am not sure if that's enough to earn if a 0 for light performance from AGS. I am sure someone else will chime in to help you.

It will certainly be a gorgeous stone, but if you want the cream of the crop, you should try and get an IS image and post here. That will really tell whether it's going to be super duper.

 

[Sparkalicious]

sslkrissi - I found a couple of websites that might be able to help you discern if your diamond is AGS0 or AGS000

Click here and here is some info from the Good Old Gold website. Your diamond numbers definitely appear to fall within AGS0 range.

eta * If you are concerned about whether or not to exclude this diamond, according to the Holloway Cut Advisor, it is does fall right within both the AGS Ideal and GIA Ex ranges and scores 1.6 Excellent. Definitely worth further consideration...
Excellent for Light Return, Scintillation and Fire and Very Good for spread (diameter for weight).

I hope that that helps!

 

[sslkrissi]

Date: 3/27/2008 12:13:49 AM
Author: honey22
Yep, the HCA is what you are looking for. If it falls into the white box (not dotted lines, these are GIA) it will be AGS Ideal.

ETA - I just had a think (sorry, bad headcold today and not totally with it

)

It will be AGS Ideal cut wise, but I am not sure if that''s enough to earn if a 0 for light performance from AGS. I am sure someone else will chime in to help you.

It will certainly be a gorgeous stone, but if you want the cream of the crop, you should try and get an IS image and post here. That will really tell whether it''s going to be super duper.

Thanks for the help! I did post the IS image in my previous topic which I pasted the link to above. I just don''t know exactly what I should be looking for in the image, to tell whether it is a keeper or not.

 

[sslkrissi]

Date: 3/27/2008 12:26:59 AM
Author: Sparkalicious
sslkrissi - I found a couple of websites that might be able to help you discern if your diamond is AGS0 or AGS000

Click here and here is some info from the Good Old Gold website. Your diamond numbers definitely appear to fall within AGS0 range.

eta * If you are concerned about whether or not to exclude this diamond, according to the Holloway Cut Advisor, it is does fall right within both the AGS Ideal and GIA Ex ranges and scores 1.6 Excellent. Definitely worth further consideration...
Excellent for Light Return, Scintillation and Fire and Very Good for spread (diameter for weight).

I hope that that helps!

Those two links were pretty helpful. What I am taking from the second link is the following: In order for a stone graded by GIA to meet the standards of a AGS000, it would need to have both an Excellent rating in Polish and an Excellent rating in symmetry, as well as fall within these specifications:

CA: 33.7-35.8
PA: 0.0-89 (?)
Culet: 0.0-3.8
Table: 52.4-57.5
Girdle: 0.5-3.0

So, I guess that means that if this stone had been graded by AGS, it would have been an AGS000. Yeah!

 

[Sparkalicious]

You''re welcome!

Just to clarify the ranges ... according to the AGS standards of an "Ideal Cut" the specs, as stated on the GOG link, should fall within the following:

Total depth: 59.9 - 62% (says 63% but most PS''ers would probably debate that getting a bit too deep)
Table %: 53 - 57.5%
Crown angle: 33.7 - 35.8 degrees
Pavilion angle: 40.5 - 41.5 degrees
Crown height: 14.4 - 16.2%
Pavilion depth: 42.2 - 43.8%

It''s also important to note that the Crown and Pavilion angles should be complimentary. This is where the HCA can be a helpful tool.

Your diamond does indeed sound as though it will be gorgeously bright and sparkly!

 

[strmrdr]

There are only 2 ways to tell if it is an AGS0 in light performance, an AGS report with cut grade or a full 3d scan entered into the AGS software.
However the AGS cutting charts and or experience can be used too tell if its an AGS0 "candidate" and it is.
The AGS box on the hca is based on the cutting charts.
It would likely get AGS0 in light performance from AGS.

 

[WinkHPD]

RE: Is there a way to tell if this GIA EX would qualify as an AGS000?

Yes, have it sent to AGS.

While this diamond will be a candidate as others have correctly said, it also must pass muster on all cut related factors to qualify. AGS is much stricter on polish and symmetry than GIA so this is an unknown when trying to determine if your gem will get the coveted AGS 0 cut grade.

Ideal Light Performance 0 (judged by diamond-specific ray tracing, not two-dimensional proportions)

Ideal Proportions Factors 0 (this is now weight ratio, durability, tilt/girdle reflection, etc.)

Ideal Finish 0 (this is polish and symmetry – the lowest score is reported)

It sounds like the diamond being discussed passes muster on items one and two and it would remain only to be seen if it also passed the Ideal Finish test. That we can not tell you without examining the gem in person. Please not though, that even if this stone ended up an AGS 1 because of finish, it would still be a beautiful gem.

Wink

 

[sslkrissi]

Date: 3/27/2008 1:15:37 AM
Author: Sparkalicious
You''re welcome!

Just to clarify the ranges ... according to the AGS standards of an ''Ideal Cut'' the specs, as stated on the GOG link, should fall within the following:

Total depth: 59.9 - 62% (says 63% but most PS''ers would probably debate that getting a bit too deep)
Table %: 53 - 57.5%
Crown angle: 33.7 - 35.8 degrees
Pavilion angle: 40.5 - 41.5 degrees
Crown height: 14.4 - 16.2%
Pavilion depth: 42.2 - 43.8%

It''s also important to note that the Crown and Pavilion angles should be complimentary. This is where the HCA can be a helpful tool.

Your diamond does indeed sound as though it will be gorgeously bright and sparkly!

I must have missed the part where they discuss depth.... it was kinda late when I was reading it last night. Anyhow, this stone is a 62.2 in depth, so I think it may be a little on the deep side, but still ok according to what you have posted. Thanks

 

[sslkrissi]

Date: 3/27/2008 1:15:48 AM
Author: strmrdr
There are only 2 ways to tell if it is an AGS0 in light performance, an AGS report with cut grade or a full 3d scan entered into the AGS software.
However the AGS cutting charts and or experience can be used too tell if its an AGS0 ''candidate'' and it is.
The AGS box on the hca is based on the cutting charts.
It would likely get AGS0 in light performance from AGS.

Can the vendor that I purchase the stone from perform the full 3d scan that you are referring to?

 

[sslkrissi]

Thanks for the info! Do you have any idea how much that would cost and how long it would take? Is this something that people often do, or do you think that most people just trust the GIA certificate? This is so hard when you don''t get to see the diamond in person before buying!

 

[Rhino]

Just a note about the link that was made to our old "classic" site.

That information is outdated and is not on our current website. AGS ideal used to be able to be determined by certain sets of numerical proportional data within a given set of tolerances (you see at that link). While there is still numierical data consulted to determine the current AGS Grade it is impossible to determine without an actual and accurate 3 dimensional scan of the diamond and processed through their proprietary PGS software along with examinations of polish and symmetry and as Wink pointed out actually done by AGS if one desires an actual AGS lab graded diamond.

Just recently we examined two diamond with virtually identical numerical data. One was an AGS 3 and one was AGS 0 based on the model.

Peace,

 

[strmrdr]

Date: 3/27/2008 11:26:14 AM
Author: sslkrissi
Thanks for the info! Do you have any idea how much that would cost and how long it would take? Is this something that people often do, or do you think that most people just trust the GIA certificate? This is so hard when you don''t get to see the diamond in person before buying!

not worth it.
Just get an IS image(which you did) it tells more than the cut grade anyway when combined with some knowledge about troublesome combos is better anyway.
Yours isn''t a troublesome combo....

 

[lovehersomuch]

i was quoted for an 1.23ct AGS000 by Bill Pearlman and it scored a 2.3 on the HCA. A GIA Excellent that i was looking at got a 1.5 on the HCA yet Bill Pearlman said that the GIA stone is more like an AGS1 because GIA''s grading scale is much broader. why would an AGS000 score 2.3 on the HCA? I have the certs and can post the numbers later today...

 

[strmrdr]

Date: 3/27/2008 5:26:11 PM
Author: lovehersomuch
i was quoted for an 1.23ct AGS000 by Bill Pearlman and it scored a 2.3 on the HCA. A GIA Excellent that i was looking at got a 1.5 on the HCA yet Bill Pearlman said that the GIA stone is more like an AGS1 because GIA''s grading scale is much broader. why would an AGS000 score 2.3 on the HCA? I have the certs and can post the numbers later today...

by having a 41.1 pavilion most likely.
HCA is overly harsh on pavilions over 41 sometimes.
Post the numbers for both....

 

[lovehersomuch]

Date: 3/27/2008 5:29:33 PM
Author: strmrdr

Date: 3/27/2008 5:26:11 PM
Author: lovehersomuch
i was quoted for an 1.23ct AGS000 by Bill Pearlman and it scored a 2.3 on the HCA. A GIA Excellent that i was looking at got a 1.5 on the HCA yet Bill Pearlman said that the GIA stone is more like an AGS1 because GIA''s grading scale is much broader. why would an AGS000 score 2.3 on the HCA? I have the certs and can post the numbers later today...

by having a 41.1 pavilion most likely.
HCA is overly harsh on pavilions over 41 sometimes.
Post the numbers for both....

AGS000:

1.213
G, SI2, No Fluorescence
Depth: 61.8
Table: 56.9
Crown: 34.8
Pavillion: 40.9
Culet: 0

1.20ct, G, SI2, GIA, EX/EX/EX, No Fluorescence,

Depth: 61.2
Table: 56
Crown: 35
Pavillion: 40.8
Culet: 0

 

[strmrdr]

Date: 3/27/2008 9:27:38 PM
Author: lovehersomuch


AGS000:

1.213
G, SI2, No Fluorescence
Depth: 61.8
Table: 56.9
Crown: 34.8
Pavillion: 40.9
Culet: 0

1.20ct, G, SI2, GIA, EX/EX/EX, No Fluorescence,

Depth: 61.2
Table: 56
Crown: 35
Pavillion: 40.8
Culet: 0

you must have entered the numbers wrong it gets a 1.9

 

[lovehersomuch]

Date: 3/27/2008 9:33:02 PM
Author: strmrdr

Date: 3/27/2008 9:27:38 PM
Author: lovehersomuch


AGS000:

1.213
G, SI2, No Fluorescence
Depth: 61.8
Table: 56.9
Crown: 34.8
Pavillion: 40.9
Culet: 0

1.20ct, G, SI2, GIA, EX/EX/EX, No Fluorescence,

Depth: 61.2
Table: 56
Crown: 35
Pavillion: 40.8
Culet: 0

you must have entered the numbers wrong it gets a 1.9

maybe.. but still the AGS000 gets a lower score then the GIA excellent....

 

[strmrdr]

Date: 3/28/2008 12:33:51 AM
Author: lovehersomuch

maybe.. but still the AGS000 gets a lower score then the GIA excellent....

lower score doesnt mean better however...

 

[whatmeworry]

Date: 3/27/2008 12:19:02 PM
Author: Rhino
Just a note about the link that was made to our old ''classic'' site.

That information is outdated and is not on our current website. AGS ideal used to be able to be determined by certain sets of numerical proportional data within a given set of tolerances (you see at that link). While there is still numierical data consulted to determine the current AGS Grade it is impossible to determine without an actual and accurate 3 dimensional scan of the diamond and processed through their proprietary PGS software along with examinations of polish and symmetry and as Wink pointed out actually done by AGS if one desires an actual AGS lab graded diamond.

Just recently we examined two diamond with virtually identical numerical data. One was an AGS 3 and one was AGS 0 based on the model.

Peace,

Which one was better looking in your opinion?

 

[lovehersomuch]

Date: 3/28/2008 12:36:19 AM
Author: strmrdr

Date: 3/28/2008 12:33:51 AM
Author: lovehersomuch

maybe.. but still the AGS000 gets a lower score then the GIA excellent....

lower score doesnt mean better however...

why is that?

why use the HCA then???

 

[Lorelei]

Date: 3/28/2008 10:26:50 AM
Author: lovehersomuch

Date: 3/28/2008 12:36:19 AM
Author: strmrdr

Date: 3/28/2008 12:33:51 AM
Author: lovehersomuch

maybe.. but still the AGS000 gets a lower score then the GIA excellent....

lower score doesnt mean better however...

why is that?

why use the HCA then???

Because it is an elimination tool rather than a selection one. The HCA can''t physically see the diamonds, what it can do is predict how well a given set of proportions can potentially work together, with diamonds which score under 2 being worth further evaluation by other means such as Idealscope, skilled vendor evaluation. Once you get a score under 2, then the HCA''s job is done.

 

[Rhino]

Date: 3/28/2008 12:42:57 AM
Author: whatmeworry

Date: 3/27/2008 12:19:02 PM
Author: Rhino
Just a note about the link that was made to our old ''classic'' site.

That information is outdated and is not on our current website. AGS ideal used to be able to be determined by certain sets of numerical proportional data within a given set of tolerances (you see at that link). While there is still numierical data consulted to determine the current AGS Grade it is impossible to determine without an actual and accurate 3 dimensional scan of the diamond and processed through their proprietary PGS software along with examinations of polish and symmetry and as Wink pointed out actually done by AGS if one desires an actual AGS lab graded diamond.

Just recently we examined two diamond with virtually identical numerical data. One was an AGS 3 and one was AGS 0 based on the model.

Peace,

Which one was better looking in your opinion?

Hey WMW,

The "0" was. I was also able to record the differences in appearance between the 2 as well. The 3 had more darkness under the table facet.

 

[Rhino]

Date: 3/29/2008 6:27:33 AM
Author: Lorelei

Date: 3/28/2008 10:26:50 AM
Author: lovehersomuch

Date: 3/28/2008 12:36:19 AM
Author: strmrdr

Date: 3/28/2008 12:33:51 AM
Author: lovehersomuch

maybe.. but still the AGS000 gets a lower score then the GIA excellent....

lower score doesnt mean better however...

why is that?

why use the HCA then???

Because it is an elimination tool rather than a selection one. The HCA can''t physically see the diamonds, what it can do is predict how well a given set of proportions can potentially work together, with diamonds which score under 2 being worth further evaluation by other means such as Idealscope, skilled vendor evaluation. Once you get a score under 2, then the HCA''s job is done.

Hi Lorelai,

lovershersomuch has a very good point. I field emails daily by folks questioning the optical appearance/performance of diamonds that constitute some of the rarest diamonds in the world (H&A types) that score over a 2 on the HCA. I got tired of fielding so many of them that I wrote an article covering what, in my professional opinion are both the strengths and the weaknesses of this technology. You may want to read it for a balanced view of how much it can or can''t be trusted. Professionally speaking, I know if I used it to eliminate diamonds the way consumers do on this forum there are many people here who would have passed up perfectly beautiful and rare diamonds.

Garry is aware of this flaw and I believe has commented along those lines on the forum before. Most people forget its strictly a predictor because I can show you diamonds with a score over 2 that are brighter than diamonds with a score of 1.

 

[Lorelei]

Rhino I appreciate your taking the time to post, but I don't think I made myself clear.

What I was trying to say ( not very well evidently

) was that once you had a diamond that scored under 2, the HCA's job was done in as much as that it was limited as to what else it could tell you about a diamond's performance/ appearance/ personality. I didn't mean that diamonds in some cases scoring over 2 weren't worthy of consideration, I have one myself and have seen some other stunners that scored well over 2, but that the HCA can only give limited info on any given diamond. I know with some of the in house diamonds listed anyway, that the cut info given such as IS images, photos, other technologies and vendor evaluation by a person such as yourself, can mean that the use of the HCA isn't strictly necessary, and I was thinking more of the HCA use for ' virtual ' diamonds, where it's use can be invaluable, to weed out amongst the hundreds of diamonds on the listings.

Also as I have said before, I try hard to help folk in not judging a diamond too harshly, by throwing it out if the numbers don't quite fit certain supertight ranges, as I personally feel there is a bit too much of a tendency to do this, and that the new posters may miss out on a potentially gorgeous diamond they could be very happy with, even if not cut to super strict standards, or just outside of. I have one myself and it is PLENTY beautiful, and I get compliments all the time, and joy every time I look at my finger. Some may think it barks on paper but it is actually a fabulous stone. So I try to find out what posters actually want, and help them find it.

I was trying to help the OP by letting him know that a lower score didn't necessarily mean one diamond was better than another when using the HCA. But I appreciate thoughtful input from an expert such as yourself, if I am not explaining something as well as I should!

BTW I haven't seen this article you wrote Jon, if you could point me to it, I would be very interested to read it!

 

[Allison D.]

It's been noted here on PS several times that the HCA doesn't "pick" diamonds, nor should it be used for such.

It's also been acknowledged several times that some gorgeous stones may end up scoring above a 2. That said, though, consumers who are spending $$ to bring in stones and potentially return them if their 'gamble' turns out to be less than hoped for can realize a bit of benefit in using the HCA.

While it may eliminate some stones (scoring higher than 2) that actually perform well, it does an efficient job at narrowing down a field where most of the remaining stones (scoring under 2) have an exceptionally strong probability of performing well.

As long as that piece is explained to consumers, I believe the HCA continues to be a useful tool for those shopping online. For those who like challenge and have $$ to apply toward challenge, I'm certain they can find stones that score above 2 that are really nice performers. For those who want to 'get to the point', stones that score below 2 represent a safer way to go.

 

[Ellen]

Jon, Allison raises a valid point, to your valid point. Many times it''s too invololved to tell a poster how a great stone can score "worse". But if I feel the situation warrants it, i.e. the poster will listen, and knows enough to know what I mean, I will elaborate on going above 2.