shape
carat
color
clarity

Diamond Grading Lab Survey

Status
Not open for further replies. Please create a new topic or request for this thread to be opened.

pricescope

Ideal_Rock
Joined
Dec 31, 1999
Messages
8,266
Hi guys, we finally published the results of Grading Lab Survey, which was solely funded by Pricescope.

That was quite a bit of work
1.gif
Garry Holloway and I decided to run this survey while skiing together in Whistler last March. It seemed so easy back then when we discussed in while sitting in the lift-chairs.
1.gif


First of all, it must be absolutely independent and funded only by Pricescope. Secondly, surveyed labs must not be aware about the survey.

The plan was to ask three separate vendors to select several diamonds from their inventories, which already had grading reports, and send them to other labs. For this first exercise we decided to limit the number of labs to GIA, EGL USA and AGS because their reports are most often for the internet diamonds, which allows doing a price analysis as well.

After getting all the certificates from the labs, the stones were shipped to David Atlas, AGA, for additional checking in his lab. Then it comes to the data analysis and most difficult part – writing an article
1.gif
.

Finally, we sent the draft to all three surveyed labs for the data verification. It was a good move because it helped us to reveal some errors in the data and most importantly that two original reports were from different stones (mix-up happens)! We had to re-examine our results and some of the conclusions.

I hope that the article is errors’ free now but if you’ll find something slipped through, please let us know.

We wish to acknowledge the help and assistance provided by Mark Turnowski, EngagementRingsDirect, Jim Schultz, DirtCheapDiamonds, and Brian Gavin, Whiteflash, who provided diamonds for this survey, making them unavailable for sale for a considerable period, and for the administrative work involved in shipping and collating information.

We are also grateful to Mr. P. Yantzer, the Director of AGSL, Mr. B. Boyajian, the President of GIA, and Mr. M. Gershburg, the Director of EGL USA, for their help in verifying the data presented in this article and constructive criticism.

Many thanks to all the friends who went thru the drafts and shared their opinions.
 

Superidealist

Brilliant_Rock
Joined
Sep 10, 2003
Messages
655
I noticed this a couple of days ago. It was interesting to note that EGL graded clarity more strictly than GIA on your sample diamonds.
 

wonka27

Brilliant_Rock
Joined
Jun 22, 2004
Messages
628
Fantastic report. This can be a very useful source of information for buyers wanting to be educated and for those who have made diamond purchases. The facts and myths at the end sum up the data and perceptions nicely!

Well done
1.gif
 

elmo

Brilliant_Rock
Joined
Jun 18, 2003
Messages
1,160
The most significant finding to me was in the conclusion, "In fact all lab grades were within a single grade of difference for color or clarity." Which to me simply affirms that grading is as much an art or opinion as it is science or standards-based.

A job well-done, guys.
 

Jennifer5973

Ideal_Rock
Joined
Oct 18, 2003
Messages
4,107
This is fascinating! Thanks so much--I can't wait to really read more thoroughly through all the fndings when I am not at work! (shhhhhhhh)
2.gif
 

pricescope

Ideal_Rock
Joined
Dec 31, 1999
Messages
8,266
Re: price analysis. We haven't explained it in much detail in the articles because it would make it even more difficult to read. Just a few short comments on the price calculations.

When getting price stats, we used filters on proportions such as depth, table, and girdle as well as polish and symmetry to get average prices for narrower ranges of diamonds graded by different labs. E.g. if the diamonds in the survey had tables and depths in a certain range, we used only these ranges as a filter when calculated the prices.

When comparing AGS0 cut stones, we only took diamonds with Ex and Id finish in consideration. If it was very good or good, then we used corresponding filter as well.

There are not too many but still some diamonds in the database with AGSL reports but not ideal cut. In average they were priced about the same as similar GIA graded stones. This gives a possibility to compare prices for the diamonds that went through AGS but falls outside AGS0 and don't have Ideal symmetry and polish.
 

jtoskey

Rough_Rock
Joined
Mar 16, 2004
Messages
13
This is first-rate work and really what PriceScope is all about: dispelling myths and providing unique education to consumers who want to seek it out. Thanks to Leonid, Gary, David and the merchants who provided the stones. Just really well done.

John
____________________
John Toskey
Blue Nile, Inc.
[email protected]
www.bluenile.com
 

glitterata

Ideal_Rock
Joined
Apr 17, 2002
Messages
4,237
Oh, fascinating! fascinating!

So assuming the retailers pass the savings along to the consumer, the smart shopper will look for a US EGL diamond graded one color higher than she thinks she wants. Then she should take it to an independent appraiser. For example, suppose she looks at a bunch of GIA stones and decides she wants a G color. She should look for an EGL F and take it to an appraiser. If he confirms that it's an F, all the better. If he says it's a G, it's probably still cheaper than a GIA G anyway. Did I get that right?

Question, Leonid: Do these results vary over the colors and clarities? (For example, is EGL more likely to agree with GIA about F color stones than I colors? Is AGS more likely to agree with GIA about VVS1 stones than SI1 stones?) Was the sample too small to answer this question?

I also wonder about what happens when you get down to SI2-I1 stones. EGL adds a grade, SI3. How does that affect the pricing and buying strategy?
 

quaeritur

Brilliant_Rock
Joined
Mar 12, 2004
Messages
1,238
I saw this a few days ago -it was a good read. Thanks for doing it and all the work that went into it!!!
 

Froof

Rough_Rock
Joined
Jul 20, 2004
Messages
54
That was absolutely fascinating! Thank you for creating such a comprehensive study!
appl.gif


I've been wanting to see a report like this since I started looking at diamonds. I eventually went with an AGS graded diamond, but did briefly toy with the idea of getting an EGL stone and saving some money. Perhaps next time I won't dismiss the idea so quickly.

I even briefly considered sending my stone to the different labs, just to see how they stacked up. Of course that idea died quickly, when I learned how much it would cost...
eek.gif
 

nicknomo

Shiny_Rock
Joined
Jun 26, 2004
Messages
197
EGL-USA doesn't look all that bad. I didn't like the fact that they were often softer on the color grading though. Depending on the size and cut of the stone, you could be looking at a big price difference due to this. Take a 1.5 H Vs2. A 1.5 G Vs2 could sell as much as 2500-3000 more. The 10% EGL discounted price makes it less of a deal since $3000>$1300.

I would have really liked to see some EGL foreign samples. That would have made for some interesting data.
 

Regular Guy

Ideal_Rock
Joined
Jul 6, 2004
Messages
5,962
diamond junky!

I guess, if the shoe fits.

Though the price analysis part continues to strain the brain (reading it twice over agin will surely help), great work!
 

pricescope

Ideal_Rock
Joined
Dec 31, 1999
Messages
8,266
Good questions. Glitterata:
----------------
If he confirms that it's an F, all the better. If he says it's a G, it's probably still cheaper than a GIA G anyway. Did I get that right?
----------------
It will depend on particular carat, color, and clarity range. Assuming all EGL-USA graded diamonds have even 10%-12% discount compared to GIA, then if a price difference between F and G is less than that - yes you saved. However, there are categories of color and clarity when 1 grade difference can cause up to 25% price change. In reality discount for EGL graded stone can vary, grading strictness can also change. But the point is that there still can be a merit buying EGL USA graded diamonds or any diamonds if there is enough information about them and a possibility to compare prices.
----------------
Do these results vary over the colors and clarities? (For example, is EGL more likely to agree with GIA about F color stones than I colors? Is AGS more likely to agree with GIA about VVS1 stones than SI1 stones?) Was the sample too small to answer this question?
----------------
Yes. I think that the sampling is not big enough to draw such conclusions.
----------------
I also wonder about what happens when you get down to SI2-I1 stones. EGL adds a grade, SI3. How does that affect the pricing and buying strategy?
----------------
There is still a lot of unanswered questions but hopefully we be able to continue such kind of studies.
 

wanderlost

Shiny_Rock
Joined
Nov 3, 2003
Messages
124
I have to agree that it was not only an interesting read, but also a very carefully constructed experiment. I really enjoyed it and would like to thank the people that aided in this test for making it happen.

I would like to draw attention to one of your last points that I feel may not state exactly what it intends:

"You can get ripped off buying an EGL USA graded diamond" - Myth. Even if you buy a one higher color EGL graded diamond than you require, GIA-GTL may grade it a color grade lower and the same clarity, but you will probably pay less.


Whereas your research proves that the points following the "myth," and a good buy can be found if you purchase an EGL USA stone when compared to GIA/AGS.... the converse of the statement: "You can't get ripped off buying a EGL USA graded diamond" is also an untrue statement. As this is your last point, you could consider deviating from the Fact/Myth answering, or simply rephrase the question.


Again, thanks very much for your study....
 

wanderlost

Shiny_Rock
Joined
Nov 3, 2003
Messages
124
I'd also like to add the following comments (primarily) from my reading on the board:

1.
----------------
All diamonds and all 3 grading reports were then shipped to David Atlas, GG, NGJA, ASG Accredited Gem Appraisers, Philadelphia, PA for additional professional evaluation and to review the grading results. ----------------


I'd be curious to see how Dave Atlas graded these stones after hearing the many stories of what a strict grader he is on color.


2. If this study is ever repeated (or is decided to be continued), I'd very much like to see how (at least a sampling of these stones) are graded by PGS. The reputation of PGS on the board is quite good. Their turnaround times (and pricing?) are superb. However, being a small lab, there is at least a bit of trepedation that is associated with purchasing PGS cert'ed stones. Evidence that would dispell some of the worries associated dealing with a lab with such a small market presence would be an excellent resource.
 

g7adrian

Rough_Rock
Joined
Jul 13, 2004
Messages
17
I would like to comment on the need of an independent appraiser. If grading is such an art, why would a consumer trust the grading of an appraiser more than the grading of a highly visible reputable laboratory? I believe most independent appraisers want to see the grading report before analysing the diamond, and would merely confirm the diamond matches the lab's grading. Rarely they would question the grading of a reputable lab. I had an experience with a Sarin analysis of an independent appraiser that reported quite different numbers than the AGS grading of my diamond, and you know what? I trusted AGS, not the independent appraiser. It is much harder to verify the reputation of an appraiser than the reputation of AGS.




I think the independent appraisal has its merits though:


  • a safeguard against mishandling errors
  • maintains the health of the industry (if there were no appraisers, the standards of reputable stores could decrease)
  • artificial piece of mind for the consumer (who sadly cannot tell with her eyes that she received what she ordered)

Adrian

 

quaeritur

Brilliant_Rock
Joined
Mar 12, 2004
Messages
1,238
Just a quick comment on the independent appraiser post above... When I took my stone in (loose), I had the appraiser examine it first, without the benefit of seeing the GIA cert. He nailed everything about the stone: color, clarity, carat weight. The only slight variation was in the Sarin reading on the table... Something like 1.25%.

I guess it boils down to finding an appraiser who knows what he/she is doing!
2.gif
 

Shay37

Ideal_Rock
Joined
Mar 1, 2004
Messages
3,343
G7Adrian, when I sent my diamond to D. Atlas for appraisal, Chris did it for me. He looked at the diamond first. Told me what he was seeing; then he looked at the GIA report. He was spot on, BTW. I guess it just depends on the procedures that your appraiser follows.

Shay
 

g7adrian

Rough_Rock
Joined
Jul 13, 2004
Messages
17


----------------
On 8/6/2004 11:22:29 PM Shay37 wrote:





G7Adrian, when I sent my diamond to D. Atlas for appraisal, Chris did it for me. He looked at the diamond first. Told me what he was seeing; then he looked at the GIA report. He was spot on, BTW. I guess it just depends on the procedures that your appraiser follows.

Shay
----------------



Even if the procedures are right and D. Altas or other appraiser does confirm the lab grading without seeing it first, why would you trust the appraiser beyond the GIA grading? You probably know more about GIA and the lab has higher visibility and reputation at stake than the appraiser. You would not say GIA has less professional standards than the appraiser. Moreover, if you do not send the diamond to a LOCAL appraiser, you do not see it before the purchase, and that in a sense defeats the purpose. The opinion of an appraiser who is not local is to me like the opinion of GIA: both analysed the diamond without I seeing it. On the other hand, if the appraiser is local most likely you will not be able to verify his/her reputation as well as you can do for GIA. It seems that the only advantage of the appraiser is that he/she comes at the end of the chain and safeguards against mishandling errors, old certificate that do not represent the diamond any more, and other tricks that may be involved. But for this purpose it would be good for the appraiser to be local and to actually give the stone to you personally.



Adrian

 

Shay37

Ideal_Rock
Joined
Mar 1, 2004
Messages
3,343
Adrian, when I picked out my stone, I pretty much knew it was going to be stellar. My reason for the appraisal was so that Chris could run it through the AGA cut charts; verify the diamond and the cert matched; agree or disagree with the cert and why; verify the cost or should-be-cost and appraise the loose diamond for insurance purposes. After obtaining the setting, Chris re-checked the diamond and the work and gave a final appraisal for insurance purposes. All of this for a quite reasonable fee.

I really didn't need him to be my "eyes" as it were. I had the B-scope, the I-scope, hearts and arrows photo, and OGI megascope. I pretty much "knew" that the diamond was going to make me happy. If I had two diamonds to choose between at that time, I might have considered sending to a local appraiser to allow me to make the final decision. However, after working with Chris at D.Atlas, I would have no problem letting him be my "eyes" for any future purchase. That level of confidence comes from working with a known and respected firm. They are completely professional and above board in their dealings. I have been a member here since March of this year, and I have yet to read anything even remotely negative about D. Atlas the company, the man, or any of his employees. Just my $.02 of course.

Shay
 

hoorray

Ideal_Rock
Joined
May 16, 2003
Messages
2,798
Congratulations Leonid! This is a great study, and really represents what Pricescope is about -- objective information for the consumer (and industry). I haven't finished reading it completely yet, but have already learned several things that I think are important in the purchasing process.

Good thinking between you and Garry, and and idea well implemented!
 

hoorray

Ideal_Rock
Joined
May 16, 2003
Messages
2,798
Adrian,

I've used independent appraisers several times, and feel they are a key part of the process. The first service they provide is ensuring that you are really getting what you are paying for. That includes validating that the stone is the right stone to match the cert, and also a second opinion that the specs are what the cert says they are. (That is key since that is what the price is based on, and this study shows the variability.) Leonid has shown that certs are still somewhat of an art, not an exact science, and since color and clarity grades significantly impact price, I think it is useful to have someone say you are getting what you are paying for.

The second big use is for an experienced opinion in the "beauty" of the stone. Specs only go so far. After that, having someone with trained and experienced eyes tell me that this is a great stone for it's specs, or apprioriate for it's use, or going to display certain types of characteristics in certain lights, etc..... is a very useful benefit. No matter how many stones I buy, I won't have their experience, and I would rather benefit from it before I buy than learn it the hard way.
 

g7adrian

Rough_Rock
Joined
Jul 13, 2004
Messages
17


----------------
On 8/7/2004 8:25:17 PM lop wrote:




The second big use is for an experienced opinion in the 'beauty' of the stone. Specs only go so far. After that, having someone with trained and experienced eyes tell me that this is a great stone for it's specs, or apprioriate for it's use, or going to display certain types of characteristics in certain lights, etc..... is a very useful benefit. No matter how many stones I buy, I won't have their experience, and I would rather benefit from it before I buy than learn it the hard way.
----------------

I would probably not buy a diamond without independent appraiser verification either, and my post was just to point out that one should not necessarily trust an indepedent appraiser more than a lab grading. Both will give you a mere opinion, neither would be 100% accurate, and the lab is entitled to as much trust as the appraiser.



But there is a big danger in needing the advice of an appraiser on the 'beauty' on the stone! 'The beauty is in the eye of the beholder' and what one likes, others will hate. For a good reason there is no standard for diamond 'beauty', and a GIA report would never comment on beauty. Look at the diamond, and if it is beautiful to you, then it is beautiful. It does not mean anything if someone else tells you it is the most beautiful diamond they have seen according to their standards. It may be mere average according to what you would like had you seen many diamonds. Beauty in diamonds, as in general, is not universal.



Adrian



 

chelsey

Rough_Rock
Joined
Aug 6, 2004
Messages
6
I am just beginning to learn about diamonds and gems.
I bought this ring which has the EGL USA report. THis report does not provide details other than the basics of weight, clarity, and color. Do all the 3 labs that you worked with provide the same information. EGL report does not have information on table etc that I have seen in your sarin reports.i.e So if it is appraised for $6837 and I buy it for $500. Did I get a good deal? What about the company called USGL who also provides reports.
Is this all one needs to buy jewelry. My intention is to buy them on the internet and sell them locally.

Thanks!

d1a.jpg
 

Richard Sherwood

Ideal_Rock
Joined
Sep 25, 2002
Messages
4,924
-----------
I think the independent appraisal has its merits though:
- a safeguard against mishandling errors
- maintains the health of the industry (if there were no
appraisers, the standards of reputable stores could decrease)
- artificial piece of mind for the consumer (who sadly cannot\
tell with her eyes that she received what she ordered)
-----------

Hi Adrian. I would like to comment on your "merits of an appraiser", and add some of my own.

I agree with your first two merits, but disagree with your third.

There is much more that figures in the quality and value of a diamond than what a consumer can tell with their eyes. A diamond might look perfectly beautiful to a consumer, yet be structurally deficient, with a feather on the girdle threatening its durability. A non-expert would have no way of knowing if something like this would be threatening, or if so to what extent.

Neither GIA or any of the other labs will comment on something like this. From reading their report, you have no idea if that feather is a problem. An independent appraiser could tell you this.

GIA also doesn't give critical information that is essential in determing the cut quality of a diamond, the crown/pavilion height/depth-angles information.

An appraiser is working on the consumer's behalf. He is hired by the consumer to protect his/her best interests. This is the only time in the grading, certifying, documenting & selling process that someone is involved who is working directly on the consumer's behalf. It is the only time you have a professional looking with a critical eye to advise the consumer on the pros & cons of that diamond.

It is human nature for people working on the selling end of the equation to up-play the positives and down-play the negatives. Sometimes they don't even mention the negatives at all. This might not necessarily be because they are deliberately doing it, but because they do not have the training and experience to recognize the negatives.

The major labs will make no comment on their reports whether a characteristic is positive or negative. They simply report the characteristics. From there on, it is up to you to have somebody translate them for you. Who would give you more peace of mind in translating this for you? The seller who has an economic stake in the matter, or a non-involved, non-influenced third party expert appraiser?

Would you consider that peace of mind "artificial"?

An gemologist appraiser can also give you his opinion as to whether the grading is correct, high, or low. These things enter into the value of a diamond. Let's say you have a diamond that barely squeaked out a certain color and clarity grade. A low G/VS2, let's say. In the trade we call this "getting lucky".

Among professional dealers, that diamond is going to trade at a greater discount than a "solid" G/VS2, for example, or a "high" G/VS2. They know from their experience that the diamond is a low G/VS2, and they won't pay as much for it, or will reject it if the pricing is not commensurate with the quality.

Once that diamond is purchased however, it's up to that particular dealer whether he passes the savings on to the consumer or prices it just the same as any other G/VS2. A savvy appraiser will recognize a diamond like this, and advise his client whether it appears they are paying the proper price taking this into consideraton, or over paying.

Again, without an experienced appraiser the consumer would assume that all G/VS2's are created equal. The Pricescope study clearly shows that is not always the case. Usually, but not always. Do you want to get stuck paying full price for the occasion when it is not? If you're looking at a 3 carat diamond, you could be talking thousands of dollars difference.

The same goes for "make", the proportions and finish of a diamond. This aspect of a diamond can dramatically effect the beauty and value of a diamond, yet many dealers are woefully ignorant in being able to judge the quality of make. They figure if it's an AGS 0, they're going to charge an AGS 0 price, totally oblivious of the drastic difference of make quality that is contained within that 1 grade (there are 10 total).

The customer could pay a high AGS 0 premium and get a "steep & deep" diamond with what Rhino calls the "ring of death".

Going by just an AGS or GIA report, the consumer would have no way of knowing. They give absolutely no indication of this sort of thing. Thankfully, many of the "cutting edge" diamond vendors on Pricescope and elsewhere will give you this additional information, but far more do not.

Would it be an "artifical peace of mind" to know that your diamond was priced appropriately for the make it has?

The GIA/AGS won't even give you a price, much less indicate if it's a fair one for the diamond.

The GIA/AGS won't even give you photos of your diamond. Can you imagine that? Here you are paying top dollar for a report, and it doesn't even include a visual image of the diamond, much less an Idealscope image, Hearts & Arrows image, BrillianceScope report, or DiamCalc results.

Here's another thing that bothers me. You can get an AGS report that says in the comments "girdle laser inscribed H&A 1000397165". So what's the average consumer assume? They assume that AGS has confirmed that the diamond is of Hearts & Arrows optical symmetry.

Yet, that might not be the case at all. AGS is merely reporting what has been inscribed on the girdle by the vendor. They are not rendering an opinion at all.

This bothers me for several reasons. Isn't H&A symmetry one of the characteristics of the diamond? If so, why doesn't AGS report it?

In addition, if they are going to report it under "comments" without verifying it, why don't they make a note of that for the consumer? "Although H&A is inscribed on the girdle of this diamond, that optical symmetry characteristic has not been checked by this laboratory".

On the other hand, an appraiser working on your behalf will verify whether or not this diamond has that (important) characteristic.

Would that give you genuine peace of mind, or "artificial" peace of mind?

Rich
 

hoorray

Ideal_Rock
Joined
May 16, 2003
Messages
2,798
----------------
On 8/7/2004 11:52:26 PM g7adrian wrote:




----------------

But there is a big danger in needing the advice of an appraiser on the 'beauty' on the stone! 'The beauty is in the eye of the beholder' and what one likes, others will hate. For a good reason there is no standard for diamond 'beauty', and a GIA report would never comment on beauty. Look at the diamond, and if it is beautiful to you, then it is beautiful. It does not mean anything if someone else tells you it is the most beautiful diamond they have seen according to their standards. It may be mere average according to what you would like had you seen many diamonds. Beauty in diamonds, as in general, is not universal.


Adrian


----------------


Agreed that you have to love the stone with your own eyes, but I believe there is value in having experienced eyes helping to understand the stone and how it will perform, or the understand differences a couple of stones you are considering. I think many first time buyers haven't seen enough stones to be able to distinguish the subtlies of different characteristics. Maybe performance would have been a better word that beauty. Even tho I've bought multiple stones, I still value the advice of someone who has more training and experience than I do.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
18,408
----------------
On 8/8/2004 10:58:55 AM chelsey wrote:

I am just beginning to learn about diamonds and gems.
I bought this ring which has the EGL USA report. THis report does not provide details other than the basics of weight, clarity, and color. Do all the 3 labs that you worked with provide the same information. EGL report does not have information on table etc that I have seen in your sarin reports.i.e So if it is appraised for $6837 and I buy it for $500. Did I get a good deal? What about the company called USGL who also provides reports.
Is this all one needs to buy jewelry. My intention is to buy them on the internet and sell them locally.

Thanks!
----------------


Dear Chelsey,
This is an appraisal, not a diamond report. It has been done on a mounted stone, not loose.
 

valeria101

Super_Ideal_Rock
Premium
Joined
Aug 29, 2003
Messages
15,809
Good to see this on the web and to hear about the excellent reviews you guys have obtained
1.gif



Is this on the way to a publisher? It should!
 
Status
Not open for further replies. Please create a new topic or request for this thread to be opened.
Be a part of the community Get 3 HCA Results
Top