Can internet cutting ratings be trusted

[mclapham]

If you look at sites like bluenile and dirtcheapdiamonds etc, they seem to rate diamonds as ''ideal cut'' diamonds (GIA) as based on only table/depth ratios.

From what I''m reading on this forum, that doesn''t seem to be sufficient.

So if cut is important, should internet sites even be considered?

 

[Richard Sherwood]

Like in the non-cyber world, its on a case-by-case basis.

Many internet vendors supply an abundance of information to support their grading, cut and otherwise.

 

[windowshopper]

that''s a little hasty---------yes cut is KING --and the depth and table are a preliminary , and very strong, indicator of the overall quality of a diamon''s cut. That BN and DCD base their cut grade on that is very reasonable...........its more than most do. Ive looked a diamonds from top top vendors and retailers and they dont offer any more than that unless pushed

 

[Mara]

Personally I don't trust ANY cut grade whether offline or online. I would rather learn about what goes into a cut grade and then make a determination myself on what the cut grade is. As you noted, almost every vendor, online and offline, is going to have their own version of the cut grade. Online you may see Fair, Good, Excellent, Ideal. SuperIdeal. Offline I have seen people call stones Tolowsky Ideal Cut's when that really isn't possible by the numbers it exhibits. Some EGL certs say TIC when that's not the case either. I have seen offline jewelers call their cuts Ideal as well. Even AGS0 cuts which many think is ideal have some characteristics from time to time that seem less than ideal.

In my opinion the best thing to do it learn about diamonds and what goes into making a cut grade. Once you have some knowledge under your belt, you will be amazed at how you can sift through titles and phrases and make your own determination on what works best for you. I feel much more comfortable knowing that if anyone is to blame for a bad selection, it's ME because the power is mine, when I have the money to spend.

So truthfully it's not just online that puts diamonds into cut grades. Visit your local jeweler and they will show you ideal vs fair or good or Excellent. Again, if you can separate the wheat from the chaff on your own, you have a leg up and can shop either online or offline with a bit more confidence than the average user.

My two cents! Good luck.

 

[Regular Guy]

I asked a similar question not long ago, and found this answer helpful...

 

[denverappraiser]

There is certainly a tendency for some diamond dealers to use the term ‘ideal’ rather loosely and it’s important to understand their usage of the word. The two dealers you mentioned are both actually fairly precise in their language. Perhaps I’m mistaken but I think they are both using AGS proportion standards, which include quite a few things beyond the table size and don’t include the depth at all. There are several other definitions of the term but this is by far the most common.

AGS Proportions Table

Neil Beaty GG ISA
Independent Appraisals in Denver

 

[strmrdr]

I dont trust anyones cut ratings.
Give me the data and I will decide for myself thank you very much.

 

[niceice]

As previously noted, there are too many variations of the definition for "ideal" and some pretty interesting "stretches" in terms of "Tolkowsky Cut" as well... Work with a vendor who will provide detailed proportions information and find a diamond that meets your selection criteria regardless of what it is being labeled as by the vendor. Awhile ago one of our on-line customers wanted to know why our "ideal cut" diamonds were so much more expensive than another on-line dealers "ideal cut" diamonds and when we went to look at the diamonds being listed by the other vendor, the polish and symmetry was Good / Good and the table diameters were in the 60% range which is FAR from our definition of ideal cut, but the customer couldn''t get past it because the vendor was using the words "Ideal Cut" in the line of the listing and "therefore it MUST be ideal cut" where we kind of thought the only thing "ideal" about the diamond is that it would have been "ideal for the person to sell it"... To each his own as the saying goes...

 

[JohnQuixote]

Date: 11/30/2004 11

9:53 PM
Author: niceice

...we kind of thought the only thing 'ideal' about the diamond is that it would have been 'ideal for the person to sell it'...

 

[Regular Guy]

I don''t know if any finer point can be brought to an understanding of this...but based:

a) on what I''m reading here, and
b) the extent to which the sort of cut data from wholesaler databases is commonly integrated into the vendor databases here....

I''m willing to take another stab....

Ana recently suggested pricing for diamonds are largely driven by intelligent market forces (prior to getting jacked up locally), such that real knowledge of non-clearly stipulated features like cut do get built into the price; I''m sympathetic with this view.

But Neil, my limited experience doesn''t confirm your statement...I don''t think the categorical data you see at Blue Nile or DCD, when it provides cut descriptions for non-signature stones, is based on explicit division by AGS proportion standards. In the case of both (as represented by the recent article presented here on Blue Nile''s Just In Time stocking strategies, and Jim''s "no mis-representation here" approach in describing the 50,000 database of diamonds at his site), only table and depth data is displayed, and I understand there is no intended representation of knowledge of specific proportion information until the diamond is in hand, available to be sarined.

John, though I appreciate the good cheer, I presume it is likewise the case with White Flash...that although you rightly take pride in the in-house stock you validate and display, you do likewise present that database of 50,000 diamonds, describing some as ideal, some as very good, etc., such that these would only be known more clearly to you, once brought in-house (though you may do less of this then most, yes?).

So, having personally gotten a diamond rated later as AGS2 (though HCA .9) from a "list" showing it as ideal, I''m curious what quality control you -- who routinely do order up these stones from these pre-categorized lists -- find.

Which is just to re-ask McAlpham original question...focusing on those diamonds not yet in-house...can internet cutting ratings be trusted?

 

[denverappraiser]

Ira,

I think the short answer was given early on by Strm. No, don’t believe a claim of ideal without significant further investigation. There just isn’t enough control over the information. In the case of dealers who are relisting virtual inventory from the wholesale databases, the claim of idealness is coming from the vendor that’s supplying it at wholesale. I’ll certainly agree that this isn’t an especially reliable source but they almost certainly made this determination on the strength of something more than table/depth data. If the statement of idealness is totally content-free, the jewelers will stop buying from them because it makes them look bad to their customers and they end up eating the shipping charges. Sure, some of them push the envelope by using things like peculiar definitions, bad lab reports and similar tricks but there are very few that will flat out lie about these things. The ones that do don’t last long in the industry. The fact that the relevant information isn’t supplied in the database for your perusal is not evidence that it wasn’t used in the cut grading. By the way, all of the issues we’re discussing apply to storefront jewelers as well and the internet based dealers.

Neil Beaty, GG ISA
Independent Appraisals in Denver

 

[Brian Knox]

Date: 12/1/2004 1

2

4 AM
Author: Regular Guy

...

So, having personally gotten a diamond rated later as AGS2 (though HCA .9) from a ''list'' showing it as ideal,...

Hi Ira,

Wow !!

What attribute(s) knocked this diamond down to a AGS2 ?

What kind of report did this diamond initially have?

Did any quantitative measures vary ?

Or was it ''fudging'' a near ideal as an ideal cut ?

What did you do after you found this out?

 

[Regular Guy]

Brian,

Coincident with this discussion, is discussion of FICs in Diamond Hangout. I hadn't been looking for one...just a well cut diamond, that also would score well on the HCA. Before going to look at the diamond, with Jim having already called it up for me, he confirmed for me with it in hand that it did score .9 on the HCA. I went, I saw, I compared with a couple of his signature stones (with my wife...frankly....neither of us thought we could discern a great deal, except that on pepsi type comparison tests. the FIC won), and we bought. Stats are below:

.9 carats
Color: G
Clarity Grade: VS2
GIA cert, laser inscripted
measurements: 6.15 - 6.18 x 3.82 mm
Proportions:
Depth 62%
Table: 55%
Girdle: medium to slightly thick, faceted
Culet: none (or, .7 v. small)
Crown: 35.8' 16%
Pavil: 40.1' 42%
Finish: Polish - Excellent
Symmetry: Very Good
Fluorescence: none
Characteristics: Crystal, Feather, Cloud
Comments: none
Round: AGS 2
Cost: $33xx

With the above plugged into the HCA evaluator, comments yield:

.9 for Total Visual Performance, within FIC range
Light Return: Excellent
Fire: Excellent
Scintillation: Excellent
Spread: Very Good

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

...based on the price, I had been suspicious of the cut, and as well, by the fact that it hadn't been submitted to AGS, but GIA instead. (And so, likewise, for those diamonds graded as "ideal" but graded by GIA, I particularly bring my questions here).

So, with the diamond in hand, though relatively clueless, with Jim's recommendation we did make the purchase decision. Later, going into Tiffany's with the diamond to compare, I am without regret. I think that when Jim first opened the wrapper and saw the AGS2 score he may have been a little surprised, too. Not sure how this all factors together. Below, in Diamond Hangout, Garry mentions that FICs are found in approx 1 in 2000, so this may or may not have been a factor. Seems like if it was understood "secretly" to be ideal, without ideal "numbers," the price might have been higher to reflect this.

Certainly, my own experience does however prejudice how I understand the databases that are widely used here....and as Neil observes...not only by internet vendors, but even more, the majority of jewelers doing business, who have only the benefit of GIA certs that say nothing whatsoever about cut, that have been categorized for them, who have no sarin apparatus to do their own checking, and so -- are out of pocket with respect to representing them to their clientele. Seems like for this reason alone, as some have written elsewhere, when doing serious diamond buying, and with due respect to Garry who would lay down his life for a good idealscope image...I continue to be number sensitive, will feel more comfortable with that 0 - 2 rating, and can't really imagine making a purchase in the thousands of dollars without the benefit of that data.

Brian, or anyone else...(edited to add) does seeing the diamond data above add anything to your understanding of how it would have been pre-sorted as ideal, but rank as AGS2?

Regards,

 

[JohnQuixote]

Date: 12/1/2004 1

2

4 AM
Author: Regular Guy

John, though I appreciate the good cheer, I presume it is likewise the case with White Flash...that although you rightly take pride in the in-house stock you validate and display, you do likewise present that database of 50,000 diamonds, describing some as ideal, some as very good, etc., such that these would only be known more clearly to you, once brought in-house (though you may do less of this then most, yes?).

Ira, you bring up good points, especially considering that the new or casual consumer may not have enough cruise-and-click experience to make distinctions.

Here is info on Whiteflash's piece of the puzzle for you.

1. If a diamond appears as “in stock ready to ship” it’s an ACA or Expert Selection stone living in our vault (over 600 pieces). We know every detail on these, and they should agree with AGS standards or better.

Edited to add: Note that this is revolving stock: We take down sold stats and put up replacement stats on a daily basis...An advantage to this is that we may have items on-site not yet appearing in the database which we can recommend.

2. If a diamond indicates “contact us for availability” it is not on-site. A weighted system has been used to rate it based on all available info (more below)

An important point is that we do not sell an off-site stone without bringing it in to analyze the details and personally inspect it for the customer. If it’s advertised as something it’s not we will definitely find out! – We do not drop-ship sight-unseen.

Since you’re being as thorough as “regular,”

(haha) maybe this information about our process will be helpful: The listing program uses a weighted system, taking into account as much info as is provided, including Cs, which lab did the grading, available proportions, polish, symmetry, girdle, etc. This diamond you linked as an example was “Very good.” That is a balance of the GIA report + Ex/Ex in polish/symmetry, coupled with girdle and table stats equal to a current AGS2 in cut (AGS2 = “very fine”). Check my math here...that's from memory.

The fifth C considered is cost. Yes, the weighting system takes value for the money into account. So it doesn’t hurt that this is a full carat, VS1 stone for under $5K. On first glance it’s deeper than Brian likes. Once brought in, if the proportions were notably out (not “very fine” in line with the rest of the stone) we would find out.

As I type this I think it’s important to comment that this is the reason such a thing as “Expert Selection” exists. They’re in-house and have been tested to list specifically as you and others are requesting. Of course, we still would like to have you as a customer even if we need to bring something in and look at it for you... The sixth C is Customer Service.

By the way, I hope you don’t think my "good cheer" was sarcasm… It was intended as appreciation of NiceIce’s wit!

(Edited to remove unwanted line breaks)

TTYL,

 

[RockDoc]

Separating the wheat from the chaff.............


There are many dealers both on the internet and in the B7M store community who will tell a prospective purchaser what he wants to hear if that will sell the stone.

Is this deliberate? In some cases yes, becuase the seller ( actually the consumer''s buyer) isn''t knowlegable and doesn''t have the training, education or equipment to really make calls as to the diamond''s quality.

Further, consider how the cut grade was determined and if the characteristics are really an industry standard. Cut grading systems based on measurements is NOT accurate. Systems that bolster different standards are out there/

For instance the term "Super Ideal" has no industry accepted listing of the requirements to make such a call for a stone.

Those who give you a grading without seeing the stone, may be stating its good when in fact it may not be.
It is also changing with improved testing equipment as well as cutters who are "experimenting" with different facetting designs.

Buy based on being COMPLETELY informed about the diamond. What may be glossed over in conversation about the diamond may end up being more of a fairy tale than fact.


Hope this helps


Rockdoc

 

[oldminer]

Most diamonds are like the people in the hometown of Prairie Home Companion on National Public Radio. In that town, among other things, ALL the children are above average.

This same fate befalls diamonds advertised as well cut, fine cut, ideal cut, or super ideal cut. The other stones, not these, are the less well cut ones and no one spends a lot of time selling them based on CUT. Those are sold based on PRICE. Nearly every diamond claimed to be finely cut is ABOVE AVERAGE. Much else is salesmanship.

There are some AGS1,2 and 3 diamonds with super looks and light return and little wrong with them. It is the old AGS system that failed to differentiate substantial differences versus unimportant issues with certain minor defects in cutting being given too much weight in reducing the overall cut grade. When I created the AGA Cut Class numbers, I attempted to correct this problem and , to my own mind, succeeded in making a better mousetrap even if it was less widely recognized. Having a big budget to promote is definitely an ingredient of what system prospers the most.

If one wishes to play it safe and cannot physically examine each and every diamond before choosing, then the AGA Cut Class system will be more useful to them than the present AGS, GIA, or EGL approaches to cut grading on their current reports. The AGA Cut Class system is conservative and does not promote problematic cutting as possibly acceptable at the highest levels.

With the advent of light behavior reporting, the world of high performance diamonds will be able to relegate "parameters" of physical measurements to a secondary role. Measurments are important, but not necessarily the complete or correct way to assess beauty of an individual diamond.

In my opinion, the AGA Cut Class grades, the HCA and the Ideal-Scope are a reasonably useful predictors of performance and they sure are priced right.

 

[strmrdr]

There are some excellent opinions expressed on this thread.
One thing I want to add is that basing the buying decision on just one piece of information/test/tool is like buying a car with the only information available is that its blue.

Making an informed decision when buying diamonds is a lot like a jig-saw puzzle when the pieces fit together in a pattern thats suitable to you then its time to buy.
Too few pieces doesnt present a very complete picture.