Can you see the difference between "Good" and "EX" polish and Symmetry? Any personal experiences?

[Richard Sherwood]

There you go stirring up the hornet''s nest again Dave (RockDiamond). I''m thinking you must have been a gladiator in a past life.

I usually can''t spot the difference between Good and Excellent polish with the naked eye, but I usually can spot the difference between Good and Excellent symmetry.

 

[John P]

Date: 7/8/2009 3:39:26 PM
Author: Rockdiamond

...Many stones are knocked on PS- in the name of consumer protection.
It would be fair to say that there are knowledgeable people who believe that there are a lot of cases where stones are knocked based on too little info...

David, I think you're preaching to the choir in this thread. I'm someone who will champion "knocked" diamonds which are outside of the commonly known PS "safe-zones" if the data has merit (example). So will Oldminer and Strm, who have replied here. So will others.

Something I won't do is knock consumer veterans for steering new shoppers to reliable "safe zones" when those same consumers demonstrate open-mindedness for alternate theories when offered by an expert with valid reasoning.

...Even reading your answer above- there were two instances where you recall seeing a problem with polish with your unaided eyes- and you don't recall if you used the loupe first, or afterwards.
It would make sense that if this was a common problem, you'd have seen it many times...

After thinking about this I believe you've provided me with an opportunity for self-improvement. I've scrutinized the Cs without louping first but my finish observations have initially been made at 10X. Most of the diamonds I spoon/cuddle with regularly have high finish so it's moot, but I do get out to places where I can run rough with the salt of the earth. I'll keep you posted.

...If 'good' polish commonly shows visible defects, than the charts make sense.
But what if just about every stone graded 'good' polish shows absolutely NO eye visible defects?
Does it make sense to downgrade every single one- based solely on a parameter which can't be seen with the naked eye?...

[First thought] Did you forget about those "no-difference naked eye downgrades" from FL-IF-VVS-VS clarity? Maybe you should wage war on that platform first? Or just search PS, it's been discussed many times.

[Second thought] Many of us agree. GIA demonstrated their agreement about EX-VG by allowing both those finish grades in the overall EX cut grade. And I agree that in the majority of cases "Good" sym/polish isn't likely to differ from Ideal-EX to the naked eye...

[Third thought] ...But the grade is lower for some reason and it's a reason having to do with craftsmanship, which is my big #1 obsession. If I were buying a diamond for myself I'd like to know the details of that grade specifically...

[Final thought] ...And since I provide advice to consumers here as if I were culling possibilities for myself I can't in good conscience give my blanket support to that grade; I'll want to know the whys and wherefores of specific cases. After all, if I were buying one for myself I would definitely want to examine it (with naked eye and loupe).

...There's no question a conversation like this can get contentious- however it's worth taking that chance if we really want to have a fair discussion airing different viewpoints...

Fair enough.

 

[John P]

Date: 7/8/2009 4:51:23 PM
Author: Richard Sherwood
There you go stirring up the hornet''s nest again Dave (RockDiamond). I''m thinking you must have been a gladiator in a past life.

I usually can''t spot the difference between Good and Excellent polish with the naked eye, but I usually can spot the difference between Good and Excellent symmetry.

Curses. Why didn''t I think of the word "usually?"

 

[Rockdiamond]

Hi David Atlas,
The page I used was the one below-
http://www.datlas.com/chrt1234rev12-2008.pdf
I found it on your website.

If there's a more current version, can you post the link? The photos in your post are too small to read.

You mentioned the AGA Cut Class system has been reviewed for a considerable number of years. May I ask who reviewed it?

You did touch upon the fact that dealers consider these ratings ( GIA Polish and symmetry) imprtant- and that they affect prices.
We agree on this aspect.
If a "good" costs less, and still looks as good as an EX, doesn't that make it an important consideration for consumers?

Date: 7/8/2009 3:58:02 PM
Author: oldminer
I find few diamonds which are truly well proportioned have little reason to be found or available with only 'good' or worse polish or symmetry. I do not lower the overall cut grade due to polish or finish grades, but do suggest that these ought to influence price and decision making. Dealers consider these grades of some importance and consumers should be advised that these details of finish account for something even if it is only a relatively small financial consideration. On rare occasions something eye-visible in finish happens in a well proportioned diamond and we all consider this in the value and quality of that individual stone.

David, I honestly can't understand the statement in red.
Are you saying that there are few well proportioned diamonds with "good" symmetry polish?


HI Richard

It might seem I'm a glutton for punishment, however I really do feel this is an important topic in the diamond world.
If a consumer hangs around here, it's easy to believe there's a consensus in the trade regarding issues like the polish grade, or David Atlas' charts. It seems as though all experts agree. In the real world, that's not the case.
Without question, being a guy swimming against a stream of people all saying the same thing is difficult- but I'm passionate about diamonds- to me, it's worth taking the heat to shed some light on this..

Now..... Richard- you mentioned that you usually could not spot the difference between Good and EX polish. Can you recall times you were able to see it naked eye?

Again, I'm not trying to impugn anyone- if someone does come up with a photo, or specific things to look for I will be happy to say I see what they are talking about.

 

[Rockdiamond]

I really like and respect John Pollard. He''s a credit to this industry.
Doesn''t mean we agree on everything, however I have tremendous respect for him.
I have tremendous respect for all the members as well. I truly regret that some are offended by the mere mention of something that might, ostensibly sound like a challenge.
I''ll bet that now that we started talking about it, John- and possibly others- will come up with examples.
Although I have not seen any, it''s possible stones of Good polish where you can see the reason naked eye exist.
However I believe that in numbers, such stones would be in the category of non eye clean VS1''s. They too exist. I''m talking RBC- not only step cut.
I stand by my statement that being able to see the reason GIA downgraded Polish to "good" naked eye is extremely rare- and I''ve never seen it documented.

John, in your "first thought", above- you relate the non eye visible difference of IF-VVS to my statement.
Earlier, I used the analogy that the difference between IF, and VVS2 is a good analogy for the range between EX,and GOOD polish.
There''s a difference- but it''s necessary to use equipment to observe the difference.
Yes, if someone said- "I want an internally flawless", than that''s what they need to look at.
If they said "I want a stone that is unquestionably eye clean." recommending IF-VVS2 as the seems pretty safe to me as a range.
If we did relate clarity to finish grading, and someone says- "I want a really well cut diamond with no visible polish defects"....how restrictive need we be?"

If we need to rule out "Good", I''m asking to see why.

 

[oldminer]

Rockdiamond, like so many who have gone before you, you failed to read the "rules of Useage" for the AGA Cut Class and assume that the system works right from the charts. It does not and it is automated utilizing these published rules. The automated system has fill in blanks and I created an ideally proportioned example and used "good" for pol and sym and also another example with "poor" for pol and sym. Using the automated grader, it still gives cut class 1A for both and provides the 2A and 4A warnings about the "good" and "poor" pol and sym. I assume that literally thousands of reviews have been made of the AGA system and I have taken constructive criticism over the years to improve it. If the GIA had published it, you would have been more familiar with it probably. I don''t have their clout, recognition or their budget. It has been included in the Octonus DiamCalc program for close to ten years or more now and stands alone as a grading system for most fancy shapes with exception of what AGS provided more recently for two or three rather specific facet designs now. The AGA Cut Class system is far more generic in grading diamonds while the AGS process is much more a wonderful branding process.

I can clearly read the numbers on the two photos, so maybe this is why you are so at odds with many others here. Should we bring your visual capability into question?

Probably not, I apologize. However, all the parameters I used were 1A with the exception of pol and sym. The final grade remained 1A on both examples. Here is a link so anyone can see how the system works rather than see the charts which without using their rules are misleading at times.
http://gemappraisers.com/oldcutgrade.asp

I said it is an important consideration for consumers and for dealers eventhough it does not change the overall AGA Cut Class. The fact that I include thse finish characteristics and show that anything below very good has a deleterious effect on potential value and possibly on appearance is warning to consumers and users of the system. I think it is important to prevent sellers from passing off inferior goods as if they were totally equal to better finished goods. Diamonds are traditionally graded well beyond what the eye can see. Invisibly less well finished goods deserve some discount and mention. Just because you can''t see a finish issue does not mean it isn''t there or has no effect on value. We all know it does have some effect, even if it means nothing to our naked eyes.

I stand by what I have said that you highlighted in red and hope for others to show either support or to say I am wrong. Again, few diamonds cut to the 1A or 1B standard, what I''d deem here as, "well proportioned", are to be found with "good" or less in finish grades. Why take the time to make the proportions so correct and not put the final touches on a diamond unless the rough simply won''t allow it? Most difficult rough is not cut to such ideal range parameters to begin with. Now, there may be a few graded "good" which the cutter had hoped to rescue "very good" out of but found a problem in finishing or the lab just graded harshly. This could occur, but I do not believe it is most common for diamonds which are being sent to GIA or AGSL that are cut with near Tolkowsky parameters to be graded to "very good" or "excellent" without some real problem having taken place with the rough, at the end game of finishing the stone or with lab inconsistency on a borderline call.

 

[Dancing Fire]

the basic buying rules according to RD...

60/60 is the best cut.
don''t need any of today''s high tech,low tech tools
trust your eyes,if the stone sparkles,buy it !!
no difference between G/G,VG/VG or EX/EX polish and symmetry.

 

[strmrdr]

Date: 7/8/2009 7:08:21 PM
Author: oldminer
I stand by what I have said that you highlighted in red and hope for others to show either support or to say I am wrong. Again, few diamonds cut to the 1A or 1B standard, what I''d deem here as, ''well proportioned'', are to be found with ''good'' or less in finish grades. Why take the time to make the proportions so correct and not put the final touches on a diamond unless the rough simply won''t allow it? Most difficult rough is not cut to such ideal range parameters to begin with. Now, there may be a few graded ''good'' which the cutter had hoped to rescue ''very good'' out of but found a problem in finishing or the lab just graded harshly. This could occur, but I do not believe it is most common for diamonds which are being sent to GIA or AGSL that are cut with near Tolkowsky parameters to be graded to ''very good'' or ''excellent'' without some real problem having taken place with the rough, at the end game of finishing the stone or with lab inconsistency on a borderline call.

I agree with you.
That has been my experience also.

 

[Moh 10]

Dancing Fire you forgot the most important thing:

You only mentioned:
60/60 is the best cut.
don't need any of today's high tech,low tech tools
trust your eyes,if the stone sparkles,buy it !!
no difference between G/G,VG/VG or EX/EX polish and symmetry.

You forgot:

Stop learning. Stay ignorant, otherwise you won't buy what Diamonds By Lauren sells.

 

[Rockdiamond]

Oldmiiner: I''m sorry if I was using the chart incorrectly.
I''m sorry to have taken the conversation off track.
I respect your work David.

The question I have, and keep asking:
If "good" polish is a potential problem in so many cases- why can''t we see evidence of this photographically.
There''s a lot of highly detailed diamond photos out there.

There''s also a great deal of difference between round, and fancy shapes in this regard.
There are certainly cases of really well cut Fancy Shaped Diamonds where the work necessary to go from "good" to "EX" might actually make the stone less attractive.

In terms of symmetry- in many cases fancy cut diamonds with asymmetrical faceting causing the "good" symmetry grade, it''s not detrimental to the face up look of the diamond.
For example- the back of a pear shape may not have exactly the same facet patterns on the left and right sides. This might be very difficult to see from the face up position- and have little or no detrimental effect. Still it would cause GIA to downgrade to "good" symmetry.
This stone might very well have other attributes that make it far more attractive than a stone of EX/EX.

It''s possible that by using formulas to eliminate diamonds we may very well eliminate some of the best ones.

 

[ChunkyCushionLover]

trust your eyes,if the stone sparkles,buy it !!
no difference between G/G,VG/VG or EX/EX polish and symmetry.

Cmon guys DR hates it when you put words in his mouth the correct quote is "Trust MY Eyes If I tell you it sparkles buy it!!"

A few of my favourtie quotes from the DBL website:

"Don't let the I1 grade rattle you"
"There's no GIA Report on this one. Our company's comprehensive appraisal included."

My personal favourite:

"Although there's a slight yellow tint in the body color of the diamond, the Fluorescence comes into play. The first time I saw this diamond, it appeared to have a slight purple tint. Once I started taking pictures, I realized, it was not my imagination. The color really appeals to me. I mean, I love totally colorless diamonds as well- but to me a D is simply different, as opposed to better."

and another one:

"It really is a combination of the sparkle of a radiant, with the glitter of a radiant." Too bad he was referring to a CUSHION.

A thread like this is truly a disservice to PS consumers and yet another thread where DBL seeks confirmation, approval and anecdotal evidence supporting his claims that novice consumers should ignore the certificate and trust his eyes.

Simply because no well respected diamond appraisers and prosumers here would ever stick their foot in their mouth and say that they can regularly see a the reasons for a "Good" polish or Symmetry grades without magnification does not mean these do not affect optics. With my youngster vision I feel I can certainly notice a lack of symmetry in 4 main or 8 main cushion brilliants under the table without magnification. This may be because the external symmetry deficiencies being graded have an affect the optical symmetry or it may be other things I don't fully comprehend but it certainly makes me question the diamond.

 

[ChunkyCushionLover]

I said it is an important consideration for consumers and for dealers eventhough it does not change the overall AGA Cut Class. The fact that I include thse finish characteristics and show that anything below very good has a deleterious effect on potential value and possibly on appearance is warning to consumers and users of the system. I think it is important to prevent sellers from passing off inferior goods as if they were totally equal to better finished goods.

BINGO!!!! I wonder who might be trying to do this?? Hmmm Cough Cough Ahem OP.

 

[arjunajane]

Date: 7/8/2009 7:51:14 PM
Author: Moh 10
Dancing Fire you forgot the most important thing:


You only mentioned:

60/60 is the best cut.

don''t need any of today''s high tech,low tech tools

trust your eyes,if the stone sparkles,buy it !!

no difference between G/G,VG/VG or EX/EX polish and symmetry.


You forgot:


Stop learning. Stay ignorant, otherwise you won''t buy what Diamonds By Lauren sells.

yeah seriously,
David these transparent attempts at trying to trick experts and others into backing up
your claims, so you can sell your products - its just..urggh. yeuck

 

[oldminer]

If "good" polish is a potential problem in so many cases- why can''t we see evidence of this photographically.


I have answered this question more than once already, but one more time and maybe you''ll see it and understand.

Diamonds are graded for color and for clarity with standards that sometimes exceed what the naked eye can appreciate. The difference between D and E color "face up view" or the difference between VVS1 and VVS2 are examples. You cannot show these eye-invisible differences in a photo any better than in real life because the eye cannot see them.

The same is basically true for what constitutes a "good" grade for polish or symmetry. The issues are present but many times are not apparent to the naked eye. If the naked eye can''t see them, then neither can a photograph display them. If one uses an enlarged photo, it is somewhat the same as using a magnifier for making them more apparent, but with digital photos there are issues of pixelation and resolution which the eyes don''t have to deal with when using a stereo microscope. If the fault happens to be eye visible, I am certain a photo can display it although it may take expertise in photography to bring the issue into clear focus. This expertise has nothing to do with diamond value, gemology or diamond grading.

In spite of the relative invisibility of "GOOD" and "VERY GOOD" finish grade constituents, "Polish" and "Symmetry", these are bargaining points which diamond dealers use to arbitrage the value of individual diamonds. Finish is related to the quality of the cutting skill or the quality of the rough and deserves a place in the haggling process for the value of each individual diamond. Even when we can''t see it with our eyes or with photos, it is something factual and objectively present which is part of the process of setting value. For these reasons, diamond consumers are entitled to be informed about these grades and entitled to being asked to pay a price according to the value of each diamond. Consumers can choose to buy a diamond with less than "Very Good" finish grades. I make it clear in the AGA Cut Class sytem that the proportion grade is not affected by these ''faults", but they are faults to be considered and selected with knowledge, not in ignorance of the facts.

 

[Serg]

Hi everyone,

I read several times and did not understand reason for fighting .

Is David(RD) main statement what: LABs grading for symmetry and polish has low correlation with Optical Performance ?
is David(RD) opponent statement what : Grading for craftsmanship in symmetry and polish is important for consumer?

Are these statements contradictive really ? How thinks what LAB grading for symmetry and polish has strong correlation with Optical Performance?
How thinks what grading for craftsmanship is not necessary ?

 

[DiamondFlame]

I think it is ridiculous to accuse anyone of stirring up controversial issues as a means to drum up more business.

In all fairness, the average customer wants the best bling he can get for his money. That''s why eye-clean SI clarity grade diamonds are often recommended to free up the consumer''s budget for acquiring visibly larger stones. I don''t see how this is any different from suggesting that Good polish/symmetry offer better value as long as the diamond''s beauty is not visibly compromised. Structurally sound diamonds that look just as beautiful to the naked eye should be an option offered to the consumer but are often left out for ''safer'' alternatives.

The perceptive consumer /PS''er knows this. But given the ''blind'' nature of buying online, diamonds which fall within safe parameters are usually recommended, not as a snub to the ones that fall outside the range but more for consumer protection and to ensure they dont end up with duds. To extend the options beyond the ''safe'' range, the use of videos is certainly a step in the right direction to overcome the ''buy blind'' factor.

Real Life > Video > Reflector Images/Statistics > Lab Cert > Buy Blind/Pot Luck KWIM?

 

[Ellen]

Date: 7/9/2009 1:14:18 PM
Author: DiamondFlame
I think it is ridiculous to accuse anyone of stirring up controversial issues as a means to drum up more business.

In all fairness, the average customer wants the best bling he can get for his money. That''s why eye-clean SI clarity grade diamonds are often recommended to free up the consumer''s budget for acquiring visibly larger stones. I don''t see how this is any different from suggesting that Good polish/symmetry offer better value as long as the diamond''s beauty is not visibly compromised. Structurally sound diamonds that look just as beautiful to the naked eye should be an option offered to the consumer but are often left out for ''safer'' alternatives.

The perceptive consumer /PS''er knows this. But given the ''blind'' nature of buying online, diamonds which fall within safe parameters are usually recommended, not as a snub to the ones that fall outside the range but more for consumer protection and to ensure they dont end up with duds. To extend the options beyond the ''safe'' range, the use of videos is certainly a step in the right direction to overcome the ''buy blind'' factor.

Real Life > Video > Reflector Images/Statistics > Lab Cert > Buy Blind/Pot Luck KWIM?

Exactly. That is what MANY of us have been saying. Over, and over, and over...... But so far, still falling on deaf ears, though I''m not sure why. It''s not a difficult concept to understand.

 

[Rockdiamond]

HI Everyone!
Serg, and DF- thank you both so much for having the balls to stand up against such a tide of hostility in the hopes of allowing a free exchange of ideas.
Why would someone be so resistant to hearing they might be able to spend less, and get a diamond just as beautiful.
And these don;t have to neccesarily be OUR diamonds-
The point I am making holds water with diamodns they look at with other sellers as well.

Serg- frankly, the reactions of a consumer like ChunkCushionLover are quite hard to explain- although I am grateful to CCL for doing some proofing on our site.
Since our pages all have descriptions written specifically about the diamond- as opposed to a database generated blurb, there are sometimes errors.
CCL- f you''d like to post photos of anything from our site that might be relevant to this conversation, I''d be happy to discuss them.

 

[Rockdiamond]

Date: 7/9/2009 7:26:56 AM
Author: oldminer
If ''good'' polish is a potential problem in so many cases- why can''t we see evidence of this photographically.


I have answered this question more than once already, but one more time and maybe you''ll see it and understand.

Diamonds are graded for color and for clarity with standards that sometimes exceed what the naked eye can appreciate. The difference between D and E color ''face up view'' or the difference between VVS1 and VVS2 are examples. You cannot show these eye-invisible differences in a photo any better than in real life because the eye cannot see them.

The same is basically true for what constitutes a ''good'' grade for polish or symmetry. The issues are present but many times are not apparent to the naked eye. If the naked eye can''t see them, then neither can a photograph display them. If one uses an enlarged photo, it is somewhat the same as using a magnifier for making them more apparent, but with digital photos there are issues of pixelation and resolution which the eyes don''t have to deal with when using a stereo microscope. If the fault happens to be eye visible, I am certain a photo can display it although it may take expertise in photography to bring the issue into clear focus. This expertise has nothing to do with diamond value, gemology or diamond grading.

In spite of the relative invisibility of ''GOOD'' and ''VERY GOOD'' finish grade constituents, ''Polish'' and ''Symmetry'', these are bargaining points which diamond dealers use to arbitrage the value of individual diamonds. Finish is related to the quality of the cutting skill or the quality of the rough and deserves a place in the haggling process for the value of each individual diamond. Even when we can''t see it with our eyes or with photos, it is something factual and objectively present which is part of the process of setting value. For these reasons, diamond consumers are entitled to be informed about these grades and entitled to being asked to pay a price according to the value of each diamond. Consumers can choose to buy a diamond with less than ''Very Good'' finish grades. I make it clear in the AGA Cut Class sytem that the proportion grade is not affected by these ''faults'', but they are faults to be considered and selected with knowledge, not in ignorance of the facts.

In terms of Oldminer, clearly he''s not happy with my criticism of his cut grading charts. This is a thorny issue as I know he''s worked on behalf of consumer, yet I feel that the charts are misleading, in spite of their intent.

David Atlas- In your own words, there have been many before me who didn''t read the rules of usage- or somehow did not understand how to use the charts. Constructively speaking -if so many others have had these problems, maybe that needs fixing.....

In spite of all this, I genuinely thank you for participating.
The reason your answers are helpful is to the readers- as a dealer myself, I''m quite aware of the ramifications of grades on prices. In fact, our position as a dealer means we regularly get calls from gemologists asking us to help clarify a market price.
Gemologists and dealers have different places in this business.
Generally speaking, a dealer is going to look at a hundred stones for every one a gemologist looks at.
We HAVE to know the values because we''re not simply assigning a value for replacement- we''re putting the money down and buying it.

David, in your statement above in red, it seems we''re in agreement. It''s simply not possible to see the defects in polish causing GIA to downgrade to G from EX or VG
We are also in total agreement that consumers should be made aware of these grades- and what they mean. Which is why I started this thread.


Going back to the photographs, and documenting this:
If the small defect that caused GIA to downgrade to Good is not visible, are the effects of it?

We can show minute differences in facet alignment, or tiny imperfections.
if there is a problem inherent with "Good" polish stones- either from the specific facet or facets needing cleaning up- or the resultant "damage to the optics" we should be able to see that in today''s hi res photos.


Above I mentioned that rounds and fancy shapes are very different in this regard.

In fact, many times a stone is left "good" polish by the cutter because of "feasibility".
Say the stone is a really nice looking 2.01 with a single facet causing GIA to downgrade to Good.
The repair of the facet- which can''t be seen naked eye- will bring the stone to 1.95ct.
Is the cutter wrong leaving that invisible defect?
If we''re speaking of round diamonds, which are cut from more symmetrical Octahedron rough, it might be smarter to go below 2cts. Also due to the fact that, rightly or wrongly, VG/VG ( or better) is practically a requirement today in a round diamond. Also due to the fact that round diamonds bring higher prices than fancy shapes.
There''s a lot of decision making involved in the cutting process.
The cutter is really between rock and hard place.
He needs to cut beautiful stones, yet maintain profitability.

The rough used for Fancy Shapes is generally far less symmetrical than the rough used for rounds.
This means that in many cases, you can polish a gorgeous 2ct pear with Good Polish Symmetry. To "improve" the polish and symmetry might actually cause the diamond to go down to a 1.75 if perfect symmetry is the goal.
If the downgrades to the pol/sym are invisible to the naked eye, should they polish away more of the diamond?
If the 2ct diamond was going to sell for $10k, the 1.75 is going to have to bring the same price- plus the additional costs for labor.
In many cases it makes far more sense to offer the lovely 2.00 as it is.

The bottom line is that there are many cutters capable of doing what''s necessary to achieve the EX Pol /Sym who feel that a larger stone of G/G is the better choice.
This in no way means they are putting out badly cut diamonds.

 

[risingsun]

Date: 7/9/2009 7:26:56 AM
Author: oldminer
If 'good' polish is a potential problem in so many cases- why can't we see evidence of this photographically.


I have answered this question more than once already, but one more time and maybe you'll see it and understand.

Diamonds are graded for color and for clarity with standards that sometimes exceed what the naked eye can appreciate. The difference between D and E color 'face up view' or the difference between VVS1 and VVS2 are examples. You cannot show these eye-invisible differences in a photo any better than in real life because the eye cannot see them.

The same is basically true for what constitutes a 'good' grade for polish or symmetry. The issues are present but many times are not apparent to the naked eye. If the naked eye can't see them, then neither can a photograph display them. If one uses an enlarged photo, it is somewhat the same as using a magnifier for making them more apparent, but with digital photos there are issues of pixelation and resolution which the eyes don't have to deal with when using a stereo microscope. If the fault happens to be eye visible, I am certain a photo can display it although it may take expertise in photography to bring the issue into clear focus. This expertise has nothing to do with diamond value, gemology or diamond grading.

In spite of the relative invisibility of 'GOOD' and 'VERY GOOD' finish grade constituents, 'Polish' and 'Symmetry', these are bargaining points which diamond dealers use to arbitrage the value of individual diamonds. Finish is related to the quality of the cutting skill or the quality of the rough and deserves a place in the haggling process for the value of each individual diamond. Even when we can't see it with our eyes or with photos, it is something factual and objectively present which is part of the process of setting value. For these reasons, diamond consumers are entitled to be informed about these grades and entitled to being asked to pay a price according to the value of each diamond. Consumers can choose to buy a diamond with less than 'Very Good' finish grades. I make it clear in the AGA Cut Class sytem that the proportion grade is not affected by these 'faults', but they are faults to be considered and selected with knowledge, not in ignorance of the facts.

Dave~when I assumed there was no way that RD could dispute your clear and well thought out response to his need for "proof" [of what the rest of us already understand], I was sadly mistaken. I will be happy to share my emoticon with you, should you continue posting in this thread:

Many people choose to purchase more expensive items because of craftsmanship. Some of it may not be visible to the naked eye, but we know that it is there. Someone took the time and had the desire to produce this item with the utmost care. Telling me that I can't see the difference is not a selling point for me. I have my own priorities and will decide what is important to me.

 

[iwannaprettyone]

..

 

[iwannaprettyone]

It is always interesting when someone asks a question, but already has their own mind made up and refuses to acknowledge other opinions no matter what the validity.

 

[Rockdiamond]

Hi Everyone,
Marian- by all means, if your preference is EX EX go for it!
Not everyone feels the same way, however. ON PS there are many times that this whole subject is boiled down to: "Oh, it''s only "Good" polish, don''t buy it"

I''m not talking about a conversation involving anything we are selling- rather someone who comes here for advice about another seller''s stone.

If your preference is to buy EX/EX, does that mean everyone has to?
In terms of proof- photos and ASET/IS are commonly used here on PS.
Why should this be any different.

Iwanna- yes, many people have no ability to see another viewpoint.
35 years experience as a diamond grader certainly would put one in a position to have opinions based on experience.
If there is an issue over polish, and I''m not correct, why should asking for a demonstration of this be a problem?

If anyone has a way to demonstrate the problem of "good" polish, and how it affects a diamond, I''m all eyes, and ears.

This is a site about diamond education- why is discussing an important subject such as "Polish" such a problem for some?

 

[Dancing Fire]

RD
sooo,IYO there shouldn't be any EX,EX stones out in the market ?

since 99.99% of the consumers can't see the difference b/t a G/G stone and a EX/EX stone.

 

[Rockdiamond]

HI DF,
How are you today?
It''s a beautiful day here in New York!

Whatever it is that you are somehow holding against me, can''t we talk?
Putting rounds aside- Fancy Shapes are my real love.
I think EX/EX is dandy.
I have purchased hundreds.
But I won''t reject a stone if it has Good polish, for that reason alone.
There have been so many exceptional stones that were "good" polish.

It''s also true that when judging fancy colored diamonds, the polish symmetry ratings take on far less importance versus colorless stones.

 

[Ellen]

Date: 7/9/2009 3:32:10 PM
Author: Rockdiamond


In terms of Oldminer, clearly he's not happy with my criticism of his cut grading charts. This is a thorny issue as I know he's worked on behalf of consumer, yet I feel that the charts are misleading, in spite of their intent.

David Atlas- In your own words, there have been many before me who didn't read the rules of usage- or somehow did not understand how to use the charts. Constructively speaking -if so many others have had these problems, maybe that needs fixing.....

In spite of all this, I genuinely thank you for participating.
The reason your answers are helpful is to the readers- as a dealer myself, I'm quite aware of the ramifications of grades on prices. In fact, our position as a dealer means we regularly get calls from gemologists asking us to help clarify a market price.
Gemologists and dealers have different places in this business.
Generally speaking, a dealer is going to look at a hundred stones for every one a gemologist looks at.
We HAVE to know the values because we're not simply assigning a value for replacement- we're putting the money down and buying it.

David, in your statement above in red, it seems we're in agreement. It's simply not possible to see the defects in polish causing GIA to downgrade to G from EX or VG
We are also in total agreement that consumers should be made aware of these grades- and what they mean. Which is why I started this thread.


Going back to the photographs, and documenting this:
If the small defect that caused GIA to downgrade to Good is not visible, are the effects of it?

We can show minute differences in facet alignment, or tiny imperfections.
if there is a problem inherent with 'Good' polish stones- either from the specific facet or facets needing cleaning up- or the resultant 'damage to the optics' we should be able to see that in today's hi res photos.


Above I mentioned that rounds and fancy shapes are very different in this regard.

In fact, many times a stone is left 'good' polish by the cutter because of 'feasibility'.
Say the stone is a really nice looking 2.01 with a single facet causing GIA to downgrade to Good.
The repair of the facet- which can't be seen naked eye- will bring the stone to 1.95ct.
Is the cutter wrong leaving that invisible defect?
If we're speaking of round diamonds, which are cut from more symmetrical Octahedron rough, it might be smarter to go below 2cts. Also due to the fact that, rightly or wrongly, VG/VG ( or better) is practically a requirement today in a round diamond. Also due to the fact that round diamonds bring higher prices than fancy shapes.
There's a lot of decision making involved in the cutting process.
The cutter is really between rock and hard place.
He needs to cut beautiful stones, yet maintain profitability.

The rough used for Fancy Shapes is generally far less symmetrical than the rough used for rounds.
This means that in many cases, you can polish a gorgeous 2ct pear with Good Polish Symmetry. To 'improve' the polish and symmetry might actually cause the diamond to go down to a 1.75 if perfect symmetry is the goal.
If the downgrades to the pol/sym are invisible to the naked eye, should they polish away more of the diamond?
If the 2ct diamond was going to sell for $10k, the 1.75 is going to have to bring the same price- plus the additional costs for labor.
In many cases it makes far more sense to offer the lovely 2.00 as it is.

The bottom line is that there are many cutters capable of doing what's necessary to achieve the EX Pol /Sym who feel that a larger stone of G/G is the better choice.
This in no way means they are putting out badly cut diamonds.

It's already been said here and here, and in countless threads. For as many times as you may have heard someone knock good pol or sym, there have been just as many times (and I would guess way more) it was not. The vast majority of fancies fall in this range, we don't discourage them. We even warn posters NOT to pay so much attention to pol and sym with them. (it's mainly in rounds and mainly with sym, but then again most people want the best cut they can afford and this is simply a non issue) Some of the most swoonable stones on here will fall under these, and some we advised posters to buy. *gasp*. But you are so intent on, I'm not sure what, that you don't hear us David, and I've said that before. The "animosity" you feel? it's not that, just frustration, at saying the same things over and over, and nothing ever changes. You can't see that in many respects, we may agree with a lot of your thoughts. And that in the real world, they would totally apply, but some do not/are not going to online, for safety sake if nothing else.

You may not like to hear someone knock a stone for whatever reason (and I feel you're painting things with a rather broad brush), I see people say stuff I don't like sometimes either. But I let it go and move on, except on rare occasions. Because overall, what goes on here works. People are happy, they find what they're looking for, and most don't bust their budget getting there. There's not a problem.

 

[oldminer]

David Atlas- In your own words, there have been many before me who didn''t read the rules of usage- or somehow did not understand how to use the charts. Constructively speaking -if so many others have had these problems, maybe that needs fixing.....

The fix is to READ THE INSTRUCTIONS BEFORE YOU use a tool or a chart. When someone Assume(s) it makes an A** out of U and ME.
No one should assume that because of experience or market knowledge that they know how to use something without reading the instructions which clearly are available. Knowing they are there, I ought not be you blamed me for not making them much larger and more visible. I''d say there is no end to placing blame and others see it the same. What a waste of time.


The bottom line is that there are many cutters capable of doing what''s necessary to achieve the EX Pol /Sym who feel that a larger stone of G/G is the better choice. This in no way means they are putting out badly cut diamonds.

I agree that such diamonds are NOT BADLY CUT because of "good" ratings on finish. I believe the way the AGA Cut Class system works also shows that I never have felt GD/GD stones were bad at all. They are minutely different from VG/VG or EX/EX and for some people, not everyone, it makes all the difference. For others, it makes no difference at all.


In spite of the fact that we seemingly don''t agree, we actually see the end result with a great deal of similar feelings. People who are willing to compromise on Finish (pol & sym) can pretty much ignore the finish rating of diamonds so long as they are ultimately content with the overall look of the diamond and the overall price. This is how many diamonds, probably most diamonds, are sold since the Internet diamond BUYER is still a small fraction of all diamonds being BOUGHT. Internet SHOPPERS are getting the message about paying attention to Finish because of the potential problems associated with buyng something sight unseen via the Internet. We suggest VG/VG as a minimum more here because it is a screening tool to help eliminate potential problems with especially selective customers. Since they are not looking at the stones in real life, they need such tools, but what they learn here may not apply so much in the world of over the counter sales. There a customer many use their own eyes to see if the Finish details count for them or not. We do agree.......As painful as it is to most everyone else here, we are mostly on the same line. Our approach to the topic makes us look distant when we are not far apart in reality.

 

[Diamond Explorer]

I will chime in here and add a few tidbits to the dialog without stoking the flames too much.

First point, A good symmetry can be noticed with an un-aided eye. Albeit it has to be a sharp eye or a large diamond, and you generally have to know what your looking for. You can notice the slightly irregular faceting that is common with "good" grades. Crown or pavilion angle's might not be even, non-pointing facets, mis-shaped facets, etc.. These are features I can sometimes notice with an un-aided eye. When I inspect a diamond for a client, I don't necessarily use a loupe, at first at least. I judge a stone with a naked eye first, just as my customer will. Now does a "good" symmetry make it unsuitable for my clients, definitely not, but it definitely will be considered as feature of the diamond and will effect the price.

Now on the issue of craftsmanship, If the yield of a piece of rough is 1.75 with excellent symmetry or 2.00 with good symetry, I would think the 2.0 could possibly show more craftsmanship as long as the diamond is pretty and still has excellent light performance.

I can see both sides of this argument, but symmetry and polish do affect appearance. That does make diamonds that are less than perfect bad by any means. Everyone wants something a little different in there diamond, and good symmetry/polish can often be a fine choice for maximizing other aspects that are more important to you.

Everyone has there own preferences and that is definitely O.K.

 

[Rockdiamond]

Thanks David.
It's very true that we do share alot of common ground in the way we look at diamonds.
What you're saying makes total sense. If one has to buy a diamond from someone not looking at it, it only makes sense to set minimums.
Part of the reason we differ in views is that I feel that purchasing a diamond from someone who's never seen it is not the best way to do it. A chrat which seemingly enables this is a flashpoint- a good way to demonstrate why buying by the numbers does not work.

I honestly feel the consumer is far better served buying from a dealer who has the diamonds, and can assist them in selection.
If I wasn't selling diamonds, I would tell that to a relative who asked where to buy.
There's a lot of great dealers who have photos, and far more info than the places with a list and a GIA report.
But if one was going to buy by the numbers, David Atlas's system is desogned to avoid any thin ice. ( even if A-hole dealers can't read instrructions)

HI Ellen!
Personally, I love talking about diamonds.
For this reason, a discussion of them , to me, should be fun!
Isn't that why we are here?


The PS polish tutorial is excellent.
It talks about grain lines in diamonds.
A diamond's grain lines may be a reason that a facet may be better left alone, as opposed to trying to go for the EX cut grade.

There's even a photo showing grain lines on a stone that would not get a "good" grade.
This kind of proves my point. There is a photo of a polish defect.
But it's too severe to achieve a grade of "good"
In fact, I'll bet that eventually someone will come up with a photo showing a facet that needs fixing.
If it's on a stone GIA graded "good" polish, it's going to be tiny.


Hi Jonathan,
Thank you so much for adding your take on this!
Some of the aspects you mentioned- such as crown angles not matching, or irregular facets would be related to symmetry, as opposed to Polish, yes?
Would non-pointing facets affect polish in your opinion?
I guess part of the reason I asked for the personal experiences is that other than cutters, I have not heard professionals in the industry who claim to be able to spot the reasons for the downgrade to "Good" polish without a loupe.
That does not mean they don;t exist- but I have spoken to quite a few professionals about this very subject.

 

[Garry H (Cut Nut)]

Date: 7/9/2009 8:45:28 PM
Author: Rockdiamond

The PS polish tutorial is excellent.
It talks about grain lines in diamonds.
A diamond''s grain lines may be a reason that a facet may be better left alone, as opposed to trying to go for the EX cut grade.
There''s even a photo showing grain lines on a stone that would not get a ''good'' grade.
This kind of proves my point. There is a photo of a polish defect.
But it''s too severe to achieve a grade of ''good''
In fact, I''ll bet that eventually someone will come up with a photo showing a facet that needs fixing.
If it''s on a stone GIA graded ''good'' polish, it''s going to be tiny.

Thank you David.
http://diamonds.pricescope.com/polish.asp is mostly my contribution and it seems there is nothing there that does not cover off this entire thread.
Sergey''s comment too - that there are 2 issues - the one you raised about what you can see, and a notation about craftsmanship. I think you would agree that in higher clarities and colours it is likely the craftmsanship standard would become a much greater issue for most buyers. (BTW I did not indicate the polish grade on the image shown.

Like wise I would be interested to know if there are any parts of http://diamonds.pricescope.com/symm.asp that you disagree with?

If you want to find some photo examples there are plenty of good Gemology books that you could find withing a 5 minute walk. Scanning a few photo''s (only), adding a notation and posting for education purposes is allowable under copyright.

If you do agree with the tutorial information then what is the purpose of this discussion?