Which one sparkles more? Do I trust my eye or HCA?

[Rockdiamond]

Date: 7/3/2009 2:36:54 PM
Author: sarap333

Date: 7/3/2009 1:22:11 PM
Author: Rockdiamond

Date: 7/3/2009 11:55:28 AM



Sarapj- its not magic, nor does it need to be rocket science.

From the sound of what you wrote, you have lived with one diamond, therefore you''ve made decisions about diamonds in general.

To really learn about the cut of diamonds it''s necessary to physically examine many of them. Any learning done solely in a book, or over the web without hands on experience has limited value.

Rockdiamond, you''re right, I am not a diamond seller; I am a consumer. However, I am also 50 years old, and I''ve seen a lot of diamonds in my years, in stores and on my friends'' and families'' fingers. I think consumer experience is valid because as Storm mentioned a few posts ago, most diamond sellers don''t live with the diamonds in the same conditions that the consumer does -- i.e., day to day wear in a variety of conditions.

My first diamond (from my first marriage in the 1980s) was a 60/60 -- a very popular cut at that time in the pre-hearts-and-arrows era. It was a very ''spready'' diamond that looked at least 15% bigger than its actual weight. It was also a very glassy looking diamond and it looked rather gray in many lighting conditions. The clarity was above average and the color was a G or an H. That''s all the information we got back then. It came with an appraisal but no certification. The appraisal was done in-house by the store; it was not an independent appraisal. A pretty common diamond transaction for those days; my friends all had similar stones. I sold the ring after my divorce and used the money to start a travel fund for my first trip to Europe.

Sara- I promise, it''s not my intent to argue with you- or anyone.
I honestly believe you''d like to learn, so let''s look at what you just wrote.
Your first diamond was not graded properly- you are telling us that, not me.

Few stores today have the tools necessary to measure a table- in the ''80''s, virtually none.
So, we have no idea what the table was.
How can we know your stone was a 60% depth?
A well cut 60/60 may look 2-5% larger than a typical Near Tolk ( Ideal Cut)- NOT 15%. That makes it sound highly unlikely your stone was 60% depth.

All due respect, but it sounds as though you''ve incorporated some totally baseless and insulting statements made about a diamond of 60/60 and simply "grafted" them onto a poorly cut diamond you bought way back when.
How exactly is this informative?

I''m very sorry you had bad experiences- leading you to mistrust B&M sellers, and to decide you''d rather try and become your own expert. Not everyone has such distrust, and wishes to become an expert.
And to again repeat, we''re an online seller like the ones you spoke of- we never speak down to anyone, hide anything, or push anyone to buy anything.

 

[Serg]

Date: 7/3/2009 2:41:28 PM
Author: Rockdiamond
Thanks Serg! As a cutter, you're in a far better position to explain some of the subtle meanings of something like a 'painted stone'

Serg; For the benefit of those consumers reading this.... Is it safe to say that there should be no concern about paining for TripleC and the stones he's considering?

Also for Serg: Would you say that the type of painting you describe is not a detriment to a diamond's cut?

Dreamer- who's to say triplec didn't look at the stone in multiple, varied lighting environments?

Although I've never encountered any, there are likely buyers who simply throw their money at a seller after looking at stones in bright spotlights, never considering looking at the stone in normal lighting...but how many?

From where I sit TripleC hasn't shown us that he has zero common sense.


It's also true that living with a stone will give a person a different perspective. To really be able to judge cut meaningfully, you'd need to live with many diamonds, over a period of time.

I'd love to get some of these diamonds that never look different- even when they are covered in hand lotion........

Or, saying a diamond will look bad once it's dirty, with absolutely ZERO proof of that is also not exactly giving helpful advice.


As Serg pointed out, no one here is throwing around a broad statement of 'trust your eyes' without considering other factors.

How many badly cut GIA EX cut grade stones have you seen, with your own eyes?

I've actually seen some that were not my favorite combination of table depth etc...but virtually no responsible diamond appraiser or dealer would call these 'poorly cut'

Dave,

re:Serg; For the benefit of those consumers reading this.... Is it safe to say that there should be no concern about paining for TripleC and the stones he's considering?

I do not see any signs of painting, at least for crown( may be minor painting is present but I do not see)

I see 1 degree tilt. It could be tilt of camera or diamond or table or pavilion. 3D model could be very helpful

re:Also for Serg: Would you say that the type of painting you describe is not a detriment to a diamond's cut?

I told about Crown painting. Pavilion painting is very rare. Digit out is reduce Performance usually

Btw. I am not cutter

 

[Lula]

It was re-appraised when I sold it many years later, that''s how I know the dimensions. It had to be reappraised since the appraisal the stone came with was basically worthless. Sorry if it wasn''t clear. I had no idea what it was when I bought it, that is true.

Friends and family always guessed the stone to be 10 to 15% bigger than its carat weight. The large table made it appear much larger than it was.

I was not referring to you or your business in my comments. I am sorry if you took my comments to be directed at you.

It is true that I have had many unpleasant experiences with B&M jewelry businesses, and from the other posts I read from consumers, not experts, I''m not the only one who feels like they'' being swindled.

 

[Rockdiamond]

Thank you Sara.
Part of the education you have gotten here means that trying to analyze the stone you sold would require us to have a lot more info than might have appeared on an appraisal.
I feel quite sure that if you actually did have a well cut 60/60, your impression would not be one of having a badly cut stone.
Although larger tables were more common years back, really well cut stones were less common- so the odds ( and your experience) indicates your stone was not the type I''m talking about.

I also appreciate your sensitivity in that many times this has, for some reason, gotten far more personal than necessary.
I''m just as angry as you about how a lot of sellers behave- wait- correct that- I''m far angrier than you! I''m mad as hell.
I''ve spent my entire adult life involved with diamonds- I''m 52. When people who are involved in the diamond business behave badly, it reflects badly on ALL diamond people.

I also believe consumer experience is very valuable.
I''m including TripleC in that statement.


Serg: I apologize, but I just can''t seem to understand your point about painting.
In simple terms: I am stating that painting is not an issue in this case- do you agree?

The bottom line for me, in this thread, is that TripleC came here for advice- I''d like to do my part to keep that intention.

 

[Lula]

Rockdiamond, you are correct, my former diamond was not a well cut 60-60. It certainly didn''t look like the 60-60s in this article by John Pollard:
What Laboratory Cut Grade Doesn''t Show

I applaud the efforts of anyone in the industry who is working to change the "buyer beware" attitude in the industry. The store that sold me my diamond in the 1980s is still in business, still doing business the old-fashioned way.

Sometime I''ll tell the story of the purchase of my emerald cut blue sapphire from a different B&M -- talk about getting swindled! -- when I took that stone to my appraiser, she just rolled her eyes when I reported what the jewelry store had told me about the cut/origin of the stone. It is a very pretty sapphire, however, and I did decide to keep it despite the misrepresentations of the seller. But that''s another story for another forum.

 

[Serg]

re:Serg: I apologize, but I just can't seem to understand your point about painting.
In simple terms: I am stating that painting is not an issue in this case- do you agree?

Dave,

I do not see any reason why painting should be an issue in this case.
But I can not do statement what painting is not an issue in this case, because I can not

1) grade diamond beauty by any single Photo ( I prefer 3D model, comparison movies,etc)
2) I can not say what this diamond has not painting . I just do not see painting here
3) P41.2Cr34.5 is very sensitive zone for proportions. Even minor painting or dig out could change balance( in any direction).

I can say what most probably Painting is not an issue in this case.

Also Painting is not what consumer should avoid. Painting could improve diamond appearance.
I do not know any research what can explain Why angle between main facets and girdle facets should be exact 11.25 degree .

For historical reason ( technical limitations to reduce productions cost) this angle had options:

3.75, 7.5, 11.25, 15.00,....

I know why 3,75 and 15+ are bad
but what angle in range 7.5- 13 is better , I do not know.

11.25 is good for uniform girdle thickness , but it is not important for optical appearance.
most probably best azimuth angle between pavilion facets depends from LGF%
For big LGF% azimuth angle between main and girdle facets should be smaller than for small LGF%( to receive uniform ETAS)

 

[Rockdiamond]

Serg- It is not my intention to "recommend" that the OP should buy the diamond.
But in fairness to all, it seems that terms are being thrown around that are overly technical, and in such a way that it makes it seem like people are knocking the diamond based on painting.
My point: there''s absolutely no evidence that there''s a problem with this stone due to painting.

 

[Dreamer_D]

Date: 7/3/2009 2:23:38 PM
Author: Serg

dreamer_dachsie,

Nobody in this thread gave advise ''trust your eyes''!

Advice is : ''trust your eyes if you want choose between these 3 diamonds had been publishes by TripleC in beginning this thread''

There are huge difference between these two type advices.

There were a few posters who said as much, without using those words. My comment was directed more generally to the issue if trusting one''s eyes versus trusting tools anyway. This question has come up many times and my response it to the general issue. However, I actually wouldn''t necessarily advise the OP the go only by his eyes in this circumstance either unless he had done as previous posters suggested and really taken the diamond for a test drive.

 

[Dreamer_D]

Date: 7/3/2009 2:41:28 PM
Author: Rockdiamond
Dreamer- who''s to say triplec didn''t look at the stone in multiple, varied lighting environments?
Although I''ve never encountered any, there are likely buyers who simply throw their money at a seller after looking at stones in bright spotlights, never considering looking at the stone in normal lighting...but how many?
From where I sit TripleC hasn''t shown us that he has zero common sense.

He mentioned that he looked at the diamond in halogens, incandescent, and by a window, which are probably all environments available in the store I presume and so would have included at least a little bit of the spot lighting, be it only indirect. Good start, but other environments would be good too -- full sunlight, under a table to simulate low lighting environments, and in diffuse daylight. I also stand by my suggestion that he compare this E to another better cut E so he is really comparing apples to apples. If he still liked it after all that, then go for it! He made an informed choice based on his preference -- yup, I said preference, I know you like to talk about that!

But I think his preference should be informed by all the available information and from what he has written, he may not have collected it yet.

And please spare me the hyperbole

 

[Sharon101]

Date: 7/3/2009 11:32:00 AM
Author: strmrdr
RG, there is a large difference between someone who doesn''t know anything about diamonds looking at them in trick lighting and someone who gets some education and looks at them under a variety of lighting.
I have no problem with someone making an informed decision by eye after careful evaluation.

For example when I did my i1 test I used scopes and angles to make sure I was comparing apples to apples.
Then I did a critical evaluation and reached a conclusion.

As far as reflector images go there is a lot of information in them that is well beyond comparing the images to a chart if someone knows what to look at.
Reflector images are just one part of the puzzle.

There is also a huge disconnect in many parts of the trade in how they look at diamonds compared to how consumers look at diamonds once they buy them.

Well said. The last part is exceptionaly intuitive and something that needs to be factored in.

I personally think that once most people buy their diamond they pretty much look at it like they would their own child. Meaning they look for the good and really get excited when it does perform well, and perhaps choose to ignore it when it doesnt!

 

[Sharon101]

Date: 7/3/2009 11:55:28 AM
Author: Moh 10
Serg I just pulled the 0.8 ct number out the the air.
Sorry, I shouldn''t do that.

I should have said lower weight, but the main point of my post remains.

Vendors who do not sell well-cut diamonds will work to discredit IS, HCA and ASET tools.
They will encourage customers to ''trust their eyes'' even if their eyes have not been trained or ever seen a well-cut diamond.

When cut education improves market demand for well-cut diamonds will grow and cutters will cut that way.

PS is all about cut education and pulling us into the future.
But watch out for old-school vendors here trying to keep us in the past.

You have to be careful because no one gets a free pass around here just because they claim to care about the future!!!

I know that vendors and manufacturers of top cut diamonds have invested heavily in this niche market. Of course they want to sell their stock.

The task for the educated consumer will be to evaluate whether the extra cut (over and above a well performing to the eyes cut) is worth the extra price, because there is an extra price involved.

To me this industry of top cut relies on there being a huge difference to the eyes in order to be accepted in the mainstream. Im not sure that there is such a difference, such that the majority of consumers will want to pay the premium. Especially since the basic playing field of cut has lifted its game and performs sufficiently well imo.

For the niche market of cut nuts, the pleasure is in the details, so the premium is worth it, such as one gets when buying a fine watch even though a generic one does the same job.

 

[Garry H (Cut Nut)]

Date: 7/3/2009 1:45:25 PM
Author: Serg
re: Generally this only occurs when a diamond is right at the size barrier. For example a 2.00ct stone. If the cutter really applies pressure during the last stage of faceting, the stone will drop under 2.00. A 1.95ct is worth so much less than a 2.00 the motivation why this would be done is clear.

David ,

Yes sometimes Painting could increase yield

But your statement is misleading( at least for consumers) .
many cutters use painting to improve diamond Appearance and Generally during such painting they lost yield , because they need decrease diameter to receive thicker girdle in Bezel points for same rough.

couple years ago GIA published wrong article in G&G what cutters use painting to increase yield

The painting seems to be crown side to about 9.75 degrees.
(The stone was not sitting flat - I tilted about 1 degree)

The table has DiamCalc Dark Zone 0.77 mono and 0.89 stereo. I would not stock such a diamond (although it could well still have nice hearts patterns)

 

[Garry H (Cut Nut)]

Date: 7/3/2009 7:31:23 PM
Author: dreamer_dachsie

Date: 7/3/2009 2:41:28 PM
Author: Rockdiamond
Dreamer- who''s to say triplec didn''t look at the stone in multiple, varied lighting environments?
Although I''ve never encountered any, there are likely buyers who simply throw their money at a seller after looking at stones in bright spotlights, never considering looking at the stone in normal lighting...but how many?
From where I sit TripleC hasn''t shown us that he has zero common sense.

He mentioned that he looked at the diamond in halogens, incandescent, and by a window, which are probably all environments available in the store I presume and so would have included at least a little bit of the spot lighting, be it only indirect. Good start, but other environments would be good too -- full sunlight, under a table to simulate low lighting environments, and in diffuse daylight. I also stand by my suggestion that he compare this E to another better cut E so he is really comparing apples to apples. If he still liked it after all that, then go for it! He made an informed choice based on his preference -- yup, I said preference, I know you like to talk about that!

But I think his preference should be informed by all the available information and from what he has written, he may not have collected it yet.

And please spare me the hyperbole

Hi DD, the other factor which has not been explained (unles I missed it) is did the OP hold the diamonds in tweezers, so light could enter to pavilion? If so the leakage = dark zone would not be apparent.

 

[strmrdr]

Date: 7/4/2009 12:26:49 AM
Author: Garry H (Cut Nut)
Hi DD, the other factor which has not been explained (unles I missed it) is did the OP hold the diamonds in tweezers, so light could enter to pavilion? If so the leakage = dark zone would not be apparent.

You missed it,
"No, the view that convinced me that the E had good light return was when the jeweler/gemologist laid them side by side on the back of her hand between her fingers (as if on a ring). Then with overhead light, it seemed that it was brighter than the G.

I compared them at different angles as well, but probably didn't look as carefully as I should have under dim light or in daytime light. I was mostly looking at the table view an I imagine that was the angle of the most light entry during my viewing."

Static Jewelery store lighting, hard to tell diamonds apart.
Which is why several people suggested viewing them in more lighting conditions before choosing.
About that time the thread went nutz.

 

[strmrdr]

woops looks like I missed a post also...
"I looked at the stones under incandescent light, fluorescent light, and some window daylight, but didn''t take the stones out in the sun. As I said, I was most impressed by the stone with the lowest score so I''m a bit confused."

Then some consumers suggested other lighting to try to settle the decision.

 

[Serg]

Date: 7/3/2009 8:32:20 PM
Author: Garry H (Cut Nut)

Date: 7/3/2009 1:45:25 PM

Author: Serg

re: Generally this only occurs when a diamond is right at the size barrier. For example a 2.00ct stone. If the cutter really applies pressure during the last stage of faceting, the stone will drop under 2.00. A 1.95ct is worth so much less than a 2.00 the motivation why this would be done is clear.


David ,


Yes sometimes Painting could increase yield


But your statement is misleading( at least for consumers) .

many cutters use painting to improve diamond Appearance and Generally during such painting they lost yield , because they need decrease diameter to receive thicker girdle in Bezel points for same rough.


couple years ago GIA published wrong article in G&G what cutters use painting to increase yield

The painting seems to be crown side to about 9.75 degrees.

(The stone was not sitting flat - I tilted about 1 degree)


The table has DiamCalc Dark Zone 0.77 mono and 0.89 stereo. I would not stock such a diamond (although it could well still have nice hearts patterns)

re:The painting seems to be crown side to about 9.75 degrees.

You want say what crown could have painting about 1.5 degree. ( Diamonds with angle 11,25 have 0 painting)
1.5 degree is very small painting and single photo is not enough to confirm such painting

 

[Garry H (Cut Nut)]

Date: 7/4/2009 1:54:40 AM
Author: Serg

Date: 7/3/2009 8:32:20 PM
Author: Garry H (Cut Nut)

Date: 7/3/2009 1:45:25 PM

Author: Serg

re: Generally this only occurs when a diamond is right at the size barrier. For example a 2.00ct stone. If the cutter really applies pressure during the last stage of faceting, the stone will drop under 2.00. A 1.95ct is worth so much less than a 2.00 the motivation why this would be done is clear.


David ,


Yes sometimes Painting could increase yield


But your statement is misleading( at least for consumers) .

many cutters use painting to improve diamond Appearance and Generally during such painting they lost yield , because they need decrease diameter to receive thicker girdle in Bezel points for same rough.


couple years ago GIA published wrong article in G&G what cutters use painting to increase yield

The painting seems to be crown side to about 9.75 degrees.

(The stone was not sitting flat - I tilted about 1 degree)


The table has DiamCalc Dark Zone 0.77 mono and 0.89 stereo. I would not stock such a diamond (although it could well still have nice hearts patterns)

re:The painting seems to be crown side to about 9.75 degrees.

You want say what crown could have painting about 1.5 degree. ( Diamonds with angle 11,25 have 0 painting)
1.5 degree is very small painting and single photo is not enough to confirm such painting

Sergey I think this little bit of painting is enough to raise the light performance - especially near the edge of the stone.
(BTW I think I can tell from 1 photo - if a stone has painting - I do it a lot, and the results seem consistent - also there are some manufacturers that we know who regularly paint the pavilion too)
(The contrast suffers from the painting, but then you know that DC Contrast is the least useful metric for me)

 

[TripleC]

Just an update -

I''ve decided (after my novice comprehension of the discussion) that I will go for the E stone. Unfortunately, this is coming from JA and they can''t let me keep it on hold and play around with different comparisons for another week or two. I would really like to make some further analyses, but at this point, I have limited choices and although I have been able to find stones with better HCA scores I will have to give myself some peace of mind based on the other factors that have been discussed.

Thanks to all for your input in this thread. It really helped me discern what more subtle factors of the cut/painting play a role in "sparkle."

If things don''t look as good when I get the actual ring, I''ll be reopening the thread with the title "don''t trust your eye"

 

[Dreamer_D]

Date: 7/5/2009 9:02:08 PM
Author: TripleC
Just an update -

I''ve decided (after my novice comprehension of the discussion) that I will go for the E stone. Unfortunately, this is coming from JA and they can''t let me keep it on hold and play around with different comparisons for another week or two. I would really like to make some further analyses, but at this point, I have limited choices and although I have been able to find stones with better HCA scores I will have to give myself some peace of mind based on the other factors that have been discussed.

Thanks to all for your input in this thread. It really helped me discern what more subtle factors of the cut/painting play a role in ''sparkle.''

If things don''t look as good when I get the actual ring, I''ll be reopening the thread with the title ''don''t trust your eye''

Good news! JA has a good return policy if I recall correctly, which is *always* a good back up to have when you buy a diamond. When you bring iit home be sure to give it a good "test drive"! And post some photos for us!