AGS certification - H&A- and other questions-expert help needed!

[Viphan01]

I know you want to retire this subject a long time ago but I''d like your professional opinion on this since it is new to me.
I''ve always been a fan ogf GIA because of their conservative, unbiased rating of diamonds. I''m facing a dilemma of having to choose an AGS certified diamond. So please help me with these questions:
1. Is AGS as conservative as GIA?
2. Do AGS diamonds cost less than GIA?
3. In term of resale value later (if applicable), would an AGS diamond be less valuable than GIA?
4. For AGS000, is it really equivalent to GIAXXX?

Also, do you think the HCA is a good tool to evaluate light return of a diamond? There is a good diamond (GIAXXX, and I was told it is H&A, but do not see the inscription of H&A on the GIA), but when I run the numbers using HCA (table=56%, depth=62%, crown angle=35.5, pavillion=40., I only get total visual performance of 2.6 (very good fire, light return, scintillation and spread). On the other hand, a diamond with 1.7 total visual performance (excellent fire, light return, scintillation and very good spread) and measurements of table=55.2%, depth=62.3%, crown angle=35.3 and pavillion=40.7, has very average H&A appeal. The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?

Last, but not least, I''m looking for a 1.70-1.80 preferably F(D-F)VVS1(VVS1-VVS2) with excellent GIA (or ideal AGS, assumming they are really equivalent based on question 4 above) cut, polish and symmetry, no fluorescence, H&A if possible. If you know of a stone like that, please let me know where to look for it.

I appreciate all your great help.

 

[WinkHPD]

Date: 7/4/2007 9:25:15 AM
Author:Viphan01
I know you want to retire this subject a long time ago but I'd like your professional opinion on this since it is new to me.

I've always been a fan ogf GIA because of their conservative, unbiased rating of diamonds. I'm facing a dilemma of having to choose an AGS certified diamond. So please help me with these questions:

1. Is AGS as conservative as GIA?

In my experience they are slightly more conservative on clarity that GIA

2. Do AGS diamonds cost less than GIA?

No, for top cuts they may actually be slightly more expensive, since their cut grade is definitely more exclusive than GIA's for the top grades.

3. In term of resale value later (if applicable), would an AGS diamond be less valuable than GIA?

No, see #2 above

4. For AGS000, is it really equivalent to GIAXXX?

No, it is better, and can be much better, depending on where in the scale the GIA XXX is. Some of the GIA XXX combos are well outside the range of the AGS 000.

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Also, do you think the HCA is a good tool to evaluate light return of a diamond? There is a good diamond (GIAXXX, and I was told it is H&A, but do not see the inscription of H&A on the GIA), but when I run the numbers using HCA (table=56%, depth=62%, crown angle=35.5, pavillion=40., I only get total visual performance of 2.6 (very good fire, light return, scintillation and spread). On the other hand, a diamond with 1.7 total visual performance (excellent fire, light return, scintillation and very good spread) and measurements of table=55.2%, depth=62.3%, crown angle=35.3 and pavillion=40.7, has very average H&A appeal. The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?

HCA is supposed to be used as an indicator, not a final determinant. You are trying to use it for a task for which it is not designed. Ask Garry Holloway your question directly, he will have a more thorough answer for you.

Last, but not least, I'm looking for a 1.70-1.80 preferably F(D-F)VVS1(VVS1-VVS2) with excellent GIA (or ideal AGS, assumming they are really equivalent based on question 4 above) cut, polish and symmetry, no fluorescence, H&A if possible. If you know of a stone like that, please let me know where to look for it.


I appreciate all your great help.

Good luck with your search.

 

[strmrdr]

1: more so
2: the same or more depending
3: same, no diamond has short term reasonable resell value unless the vendor has buy back then its 75% to 85%. Basically the new price will need to double to get your money back.
4: AGS0 is stricter than GIA EX

Depending on the scanner used those 2 stones are within the margin of error of the lesser scanners of each other.
IS or ASET and Heart images would have too settle it.

 

[Viphan01]

Thanks, Wink for your quick response!

 

[WinkHPD]

You are welcome, looks like I beat the Storm Meister by a lightning bolt.

But it looks like he and I are in accord also.

Wink

 

[Ellen]

Date: 7/4/2007 9:25:15 AM
Author:Viphan01
The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?

Last, but not least, I''m looking for a 1.70-1.80 preferably F(D-F)VVS1(VVS1-VVS2) with excellent GIA (or ideal AGS, assumming they are really equivalent based on question 4 above) cut, polish and symmetry, no fluorescence, H&A if possible. If you know of a stone like that, please let me know where to look for it.

I appreciate all your great help.

Online, I would buy a diamond with a great Idealscope image, in which case you don''t need the HCA.

I suppose you know, but I will throw in to be prudent, that the clarity level you''re seeking isn''t really necessary, unless you just want a mind clean diamond.

Here''s one, this is all I found with a quick look. Those specs won''t be particularly easy to find. If you lower clarity (and color to maybe G) it would make it easier.

http://204.17.89.15/diamond/3050/

This is VS2, which would still be lovely.

http://204.17.89.15/diamond/2622/

 

[Viphan01]

Beautiful stones. Thanks, Ellen!

 

[Ellen]

You''re welcome, and good luck on your search!

 

[belle]

Date: 7/4/2007 9:25:15 AM
Author:Viphan01

1. Is AGS as conservative as GIA?

yes

2. Do AGS diamonds cost less than GIA?

no

3. In term of resale value later (if applicable), would an AGS diamond be less valuable than GIA?

no

4. For AGS000, is it really equivalent to GIAXXX?

yes

1. Is AGS as conservative as GIA?
2. Do AGS diamonds cost less than GIA?
3. In term of resale value later (if applicable), would an AGS diamond be less valuable than GIA?
4. For AGS000, is it really equivalent to GIAXXX?

now really, all of those aren't necessarily questions that deserve only 'yes' or 'no' answers so i will expound a bit more here. ags is a highly reputable lab that has made great progression in cut grading over the years. their consistency and attention to detail has earned them a place of respect in the jewelry industry and among consumers as well. in my opinion, they are more reliable and informative than gia by a pretty good margin. if i had a choice between the two i would, without hesitation, pick ags. i am very impressed by the work they do and the services they offer.

Also, do you think the HCA is a good tool to evaluate light return of a diamond?

no, because you would actually need the diamond in hand to truly evaluate light return.

There is a good diamond (GIAXXX, and I was told it is H&A, but do not see the inscription of H&A on the GIA

a diamond inscription can say anything, so having an inscription of 'h&a' or not, does neither qualify or disqualify a stone from being 'h&a'.

There is a good diamond (GIAXXX, and I was told it is H&A, but do not see the inscription of H&A on the GIA), but when I run the numbers using HCA (table=56%, depth=62%, crown angle=35.5, pavillion=40., I only get total visual performance of 2.6 (very good fire, light return, scintillation and spread). On the other hand, a diamond with 1.7 total visual performance (excellent fire, light return, scintillation and very good spread) and measurements of table=55.2%, depth=62.3%, crown angle=35.3 and pavillion=40.7, has very average H&A appeal. The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?

again, we are back to two basic things:
1. hca makes a *prediction* of diamond performance based on angle combinations. it can't tell you exactly how a diamond will look because there are variables that cannot be accounted for without the diamond being in hand. h&a is one of those variables!

2. h&a is a non-standardized (

The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?

it really depends on what the scores were. once you get around 2.0 on the hca, you are looking at better than average diamonds. if i had two diamonds in the 2.0 range, i would look at idealscope and aset images to determine light leakage and optical symmetry to make a decision if i could not evaluate them in person. i wouldn't try to pick between them with hca alone.

Last, but not least, I'm looking for a 1.70-1.80 preferably F(D-F)VVS1(VVS1-VVS2) with excellent GIA (or ideal AGS, assumming they are really equivalent based on question 4 above) cut, polish and symmetry, no fluorescence, H&A if possible. If you know of a stone like that, please let me know where to look for it.

use this search http://www.pricescope.com/sift.aspx
it has diamonds listed with the hca score already calculated

also, keep in mind, that color and clarity are not important factors in performance. a well cut diamond of lower color will outperform a poor cut diamond of higher color. focus on cut!

best of luck!

eta: oh wow, lots of responses came in while i was taking the time to answer!

 

[Viphan01]

Thanks for your very detailed answers.