Difference between AGS 1A and AGS 1B

[BlingItOn]

Hi,
I am rather new to the forum and totally inexperienced when it comes to diamonds, so please forgive me if this is a stupid question, but what is the difference between an AGS 1A and and AGS 1B grading?

Does 1B mean that it is worse than 1A?

Also, is a diamond graded 1B still within the AGS Ideal Range or should I be looking out for an AGS 0?

Why is there AGS and then there is AGSPGS? Is this a different grading system?

Thank you so much in advance and I apologize for the many questions.

And....HAPPY NEW YEAR everyone!

 

[diamondseeker2006]

Welcome! There are no stupid questions here!

Are you maybe asking about the AGA Cut system here?:

http://diamonds.pricescope.com/round.asp

Because that is not the same as the AGS lab that grades ideal cut diamonds. But yes, 1A is more desirable than 1B, and AGS0 stones will generally fall into the 1A parameters. AGS now grades light performance on stones, so that is another factor in the grading.

Most of us will recommend looking for an AGS0 stone or a GIA Excellent stone that falls within ideal cut parameters.

Happy New Year to you, too!

 

[BlingItOn]

Date: 1/1/2008 12:23:25 AM
Author: diamondseeker2006
Welcome! There are no stupid questions here!

Are you maybe asking about the AGA Cut system here?:

http://diamonds.pricescope.com/round.asp

Because that is not the same as the AGS lab that grades ideal cut diamonds. But yes, 1A is more desirable than 1B, and AGS0 stones will generally fall into the 1A parameters. AGS now grades light performance on stones, so that is another factor in the grading.

Most of us will recommend looking for an AGS0 stone or a GIA Excellent stone that falls within ideal cut parameters.

Happy New Year to you, too!

Thank you very much for your reply diamondseeker2006.

Yes! I was asking about the AGA Cut System instead...Sorry! It gets rather confusing for me sometimes!

The DH and I are contemplating a diamond that was graded as a GIA "Excellent" in Cut but it was not AGS Certified, so I wanted to know how it may measure up on an AGS Certification. Based on its specs, it seems to fall under the AGA 1B Category.

I really appreciate the response! Thanks again.

 

[BlingItOn]

Am I right to say that an AGA SYstem Cut 1B still falls within "Ideal" parameters but may not be considered AGS0?

 

[Regular Guy]

Date: 1/1/2008 1:36:22 AM
Author: BlingItOn
Am I right to say that an AGA SYstem Cut 1B still falls within 'Ideal' parameters but may not be considered AGS0?

In consideration of Dave's system (he actually regards as dated), and the idea that something could be "more" or "less" ideal...Dave would say, I think it was less ideal. But may not by much. So...it's still "1."

Several systems are invoked here. AGS, GIA, AGA. HCA hasn't been mentioned, but it should. Given the HCA charts...if you want to know "if it may be considered AGS0?," use them (top right, under Tools...the Cut advisor). What are the proportions of the stone your asking about? Knowing these, plotting them in that HCA tool, will at least begin to help you predict whether the diamond would make AGS0.

Finally, DS says: "AGS now grades light performance on stones, so that is another factor in the grading." I do really think this is adopting the language of AGS to a purpose that may aid visualization, for a loss of accuracy. Really...I just think AGS's system just mix together Lycra with HCA. That is...previously it used proportions...and now it does that again...but only a) by getting a close "Lycra like" measure of the diamond, and then b) applying HCA like analysis to the proportions, i.e, the considered impact of light performance given a matching of specific angles...rather than trying to band together angles as a group...and so the proportion data is individuated that way.

BTW, where you ask about the difference between AGS and AGSPGS...I understand PGS is part of the tools AGS use to cypher the proportions...it is software used in the process to set the grade. Some vendors, for example, may use it to approximate this, too.

 

[BlingItOn]

Date: 1/1/2008 2:20:48 AM
Author: Regular Guy

Date: 1/1/2008 1:36:22 AM
Author: BlingItOn
Am I right to say that an AGA SYstem Cut 1B still falls within ''Ideal'' parameters but may not be considered AGS0?

In consideration of Dave''s system (he actually regards as dated), and the idea that something could be ''more'' or ''less'' ideal...Dave would say, I think it was less ideal. But may not by much. So...it''s still ''1.''

Several systems are invoked here. AGS, GIA, AGA. HCA hasn''t been mentioned, but it should. Given the HCA charts...if you want to know ''if it may be considered AGS0?,'' use them (top right, under Tools...the Cut advisor). What are the proportions of the stone your asking about? Knowing these, plotting them in that HCA tool, will at least begin to help you predict whether the diamond would make AGS0.

Finally, DS says: ''AGS now grades light performance on stones, so that is another factor in the grading.'' I do really think this is adopting the language of AGS to a purpose that may aid visualization, for a loss of accuracy. Really...I just think AGS''s system just mix together Lycra with HCA. That is...previously it used proportions...and now it does that again...but only a) by getting a close ''Lycra like'' measure of the diamond, and then b) applying HCA like analysis to the proportions, i.e, the considered impact of light performance given a matching of specific angles...rather than trying to band together angles as a group...and so the proportion data is individuated that way.

BTW, where you ask about the difference between AGS and AGSPGS...I understand PGS is part of the tools AGS use to cypher the proportions...it is software used in the process to set the grade. Some vendors, for example, may use it to approximate this, too.

Thanks for the explanation Regular Guy!

I plugged the stats/angles into the HCA Cut Advisor and it scores a 1.5 - Excellent within TIC Range. It falls both within the GIA Excellent Range and just bam smack within (or rather ON) the AGS0 range. The thing is, I don''t really know what to make of the results....

It says that 0-2 are considered "Excellent" but consumers should probably be looking for a HCA 1-2? So, does that mean the lower the grade is better (i.e. 0.1 is desired since 0 is impossible), or does it mean that I shouldn''t be looking for a grade less than 1 since I should be looking for a HCA Score of 1-2?

I asked about the AGSPGS as well because it also falls just slightly within the PGS Grade 0 range but again I don''t really know what to make of it. Now I do.... I appreciate your letting me know the difference! Thanks again!

Many apologies for the many many questions! I am obtaining my diamond from a regular B&M Store that came highly recommended by a couple of friends who have used them to purchase their diamonds.
I did not start off asking for an "Ideal" diamond but was offered this one because the jeweller was trying to explain to me the importance of a well-cut stone. It displays H&A (we looked through the scope!) and the DH and I were told it was an "Ideal" cut.
As long as it would sparkle the way an "Ideal" Cut Diamond would perform, I am happy. I hopefully will not over-analyze the stats.....Er, not too much at least.

It would just be nice to know.....

 

[diamondseeker2006]

Bling, you interpreted it correctly, that your x fell within AGS0 and GIA Excellent ranges. A 1.5 on the HCA is terrific. Most great stones fall between 1 and 2, and it does not mean a lower or higher score within that range is better. We see a few at .8 or .9, but that does not mean they are better than a 1.5 at all. I have one GIA Excellent stone that falls within AGS0 (and has actually been tested for AGS light performance because it came from Good Old Gold), and I have two very similar, smaller diamond in earrings that are AGS0, and you certainly cannot tell them apart!

So you understand that the key is to find the stone that falls within the AGS0 range when graded by GIA. You're doing great learning how this all works!

It sounds like your jeweler values a well cut stone, which is great. You might want to use this tool to compare prices to make sure the B&M prices are reasonable. They may be a little higher than these prices, but it is not worth it to pay a huge premium.

https://www.pricescope.com/sift.aspx

Put in Excellent-Excellent for cut, check only AGS and GIA for labs, and put in the size, color, and clarity you are looking at. If you are looking at a stone that is .78 carats, for example, put .75 to .79 in the boxes.

 

[oldminer]

For round diamonds, most AGA 1B stones will still be AGS 0 cut stones. The AGA system is for screening and may eliminate some diamonds found to be "ideal" in the newest systems. However, while it is an older idea, 1980''s vintage, it is very useful.

AGA alos now directly measures light perfomance with patented ImaGem equipment. Unlike labs which use ray tracing and forecasting, AGA uses the actual performance of the individual diamond to determine how well it handles light. This is a technology which I feel will likely be embraced by a larger part of the industry as consumers find that it is the correct missing link in the total diamond grading chain. New ideas and new technology don''t become reality overnight.

 

[BlingItOn]

Thank you so very much for taking the time to shed light on all this for me DiamondSeeker2006! It's really helps because I feel like I am making a more well-informed decision!

Yes, I did compare the prices online using the Pricescope Tool and I do find that there is a premium when it comes to buying from a B&M for sure!

Unfortunately, I am not located in the USA, so after shipping/insurance & taxes, it makes it a fair deal to be buying from a B&M, where I don't have to worry about returning the stone if I didn't like it IRL, and I have more choices to look at and compare whenever I 'pop' in etc....

Before this jeweller was recommended to me, I did a little window shopping as well, and I find that sometimes, the Jewelry Salesperson uses the terms to describe a diamond rather loosely. For example, they'd call any color "Colourless" meaning that it looks or faces up "Colourless" and not that it falles within the GIA's "Colourless" range. Similarly, some will call a diamond "Ideal" (and charge you a premium) simply because it was a patented cut or for whatever other reasons, but what I'd really like to know is where their "Ideal" really falls when it is graded across the board by a respectable certification or method.
And obviously you have a few different Salespeople telling you different things.......

So far, this jeweller has been honest, upfront and helpful with us....and this Diamond looks like it has a lot of potential, but I thought I'd do a little research on my own just so I know we (me and the jeweller) are talking about the same things when we speak of "Ideal".
And this place is a tresure trove of information!!!

Thanks for clarifying that for me as well Oldminer! That's good to know!