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Rappaport Side Effect

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BlingChaser

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Here is an interesting story which i thought i might share with the forum and was hoping to get some feedback possibly from dealers and appraisers:

On my most recent visit to my Brick and Mortar jeweller (had bought a 1.81 round E SI2 previously and was looking to buy a bangle) he started telling me how this time of the year is slow for engagement ring material but very busy for gold trinkets and the occasional big purchase. He just had 2 clients in for a 3.35 and 5.2 stones which were waiting to be set. Since he had nothing else to do he showed me and my wife the 2 stones.

Using a loupe and the trusty idealscope and ideal light (i never go there without these), these diamonds seemed to be beautifully i.e cut good light return and pronounced arrows .

He then proceeded to tell me how if i wanted he could cut me a good deal on 1ct stones since he has too many and wanted to buy bigger stones. He showed me 12 stones and all of them were 1.00 - 1.02 without showing me their respective certificates. Out of the 12 i only possibly like 2 as i tend to be very conservative since i do not have a lot of experience looking at stones.

The reason i discarded the other 10 stones was due to the fact that they either were deep ( thin arrows) or the girdle seemed thick in comparison with the 2 good ones.

Now since Rappaport breaks down price according to some carat range: [1.00ct - 1.49ct], [1.50 - 1.99], [2.00 - 2.99] (do not know what comes afterwards), it seemed to me that there is a higher chance of getting shown a bad cut (bigger depth and girdle) if you choose a stone with a carat towards the low end of the rap range. That is stones of carat 1.00, 1.01, 1.50, 1.51, 2.00, 2.01 have a higher chance of having bad cuts as the diamond cutter would have an incentive to push the stone in that rappaport range.

I was hoping dealers and appraisers could comment on the above statement and i was also wondering if the same applies to bigger stones say 3.01 and 5.01 carats.

By the way is there a good way o figuring out if girdle is thick or not?
 

oldminer

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You pose a good question? There may be no logic in the way the actual market works as much as we would like to believe it is a logical market. It is a free market, but things we see as logical often are not there. I see no tendency for makes to get better or worse near cut off zones according to price charts. There are mnay poorly cut diamonds which weigh 1 carat that would weigh far less if well cut, but there are plenty of customers for poorly cut 1 carat stones. If demand wasn''t there, the cutters would change how they cut.

Larger diamonds have fewer poorly cut round shapes as sophisticated, more affluent and knowledgeable, customers tend to want a better cut diamond. Yet, there are poorly cut large diamonds floating around for the bargain hunters and those who want to show size, not quality.
 

oldminer

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John; As always your answer is thorough. It goes further than I did with the Yes, No and Maybe thing we all face. Cutters will cut diamonds they happen to have a need for within their own customer base. What they cut may well be very different another cutter would cut from identical rough because another cutter will have different customers with different needs.

Machines can help cutters plan the outcome, but the human mind is what cutters rely on when it comes to "What can I sell?" or "What do my customers want?" The old guys did things in their own way, but often did a great job, especially when one considers the limited tools they had to help them.
 

strmrdr

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thank you John & Dave exellent views from both sides of the industry!!!
 

BlingChaser

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Date: 12/27/2006 12:42:01 PM
Author: oldminer
You pose a good question? There may be no logic in the way the actual market works as much as we would like to believe it is a logical market. It is a free market, but things we see as logical often are not there. I see no tendency for makes to get better or worse near cut off zones according to price charts. There are mnay poorly cut diamonds which weigh 1 carat that would weigh far less if well cut, but there are plenty of customers for poorly cut 1 carat stones. If demand wasn''t there, the cutters would change how they cut.

Larger diamonds have fewer poorly cut round shapes as sophisticated, more affluent and knowledgeable, customers tend to want a better cut diamond. Yet, there are poorly cut large diamonds floating around for the bargain hunters and those who want to show size, not quality.
"but there are plenty of customers for poorly cut 1 carat stones"

I am not certain if those customers indeed realise what they are getting. Before coming to this forum, i had no idea how much cut influenced the beauty/pricing of a stone.
 

BlingChaser

Rough_Rock
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Nov 7, 2006
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2. Demand drives turnover. Demand for superideal rounds is not as high as it is for common commercial makes. It takes more time, and more ct weight, to produce a diamond to precision xyz specs. Cut particulars are not well-known in commercial markets so size/color/clarity drive most purchase decisions, not cut. That is why you will find 0.97 ct ‘superideals’ in shorter supply than 0.97 ct commercial makes: A piece of rough that would finish as a 0.97 ct Tolkowsky/super-duper-H&A will often be sent to a commercial cutting floor where it will finish as a 1.00 ct steep/deep or off-make. That allows it to save the critical 1ct mark that brings the best price in many markets.

I would imagine the "saving" happens every time as there might always be the off chance that a retailer could flog it off to an unknowing customer. Even my b&m jeweler tried that on me by showing me so many stones. It becomes a case of throwing something at the wall until it sticks.

From now on i''m not looking at borderline carat weights unless it''s on the left side of the borderline.

Thanks for the great reply John!

By the way is there an easy way to gauge girdle thickness?
 

JohnQuixote

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Date: 12/27/2006 4:00:30 PM
Author: BlingChaser



From now on i'm not looking at borderline carat weights unless it's on the left side of the borderline.

I wish it were that easy. By doing that you'd be eliminating some of the best options from sellers of premium goods that finished on a key weight, precisely as planned.Furthermore, this strategy doesn’t guarantee safety:Remember that rough comes in all shapes and sizes.The best plan, even for some steep/deep, very shallow or off-makes, will have them finishing just under a key weight as no other choice was possible.

You’re right-on when you say that many off-makes are ‘flogged’ to unknowing consumers, and for years the average consumer hasn't noticed the flogging.Why?Because jewelry store lights make everything look pretty good and the other Cs are used to drive sales in many markets.Education about cut is not nearly as available & user-friendly.GIA having a cut grade is a great step towards getting people to start asking ‘what does this mean?...’ but it’s only a start.

My suggestion for consumers is to educate yourself about cut and only work with professionals you trust who have the standards you're seeking.


Date: 12/27/2006 4:00:30 PM
Author: BlingChaser

Thanks for the great reply John!

By the way is there an easy way to gauge girdle thickness?

Yes.Look at the grading report from the lab or, failing that, a Sarin, Helium or OGI report run on the diamond you’re considering.

Judgments can be made by experienced graders with a loupe, but the visible differences can be hard to deduce. See the sims below; one is predicted as GIA thin avg, the other GIA medium. They are only microns of difference at the borders so a lab report or scan is most decisive.


Girdle4BC.jpg
 

strmrdr

Super_Ideal_Rock
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kicken thanks John :}
 

hikerchick

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Nov 29, 2006
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John, you are always so full of interesting information . . . THANK YOU . . .
 

oldminer

Ideal_Rock
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Here is a more complete chart of relative girdle thickness that I modifed to fit the Durability-Finish-Size grading system we developed. It may be a good reference. It takes experience to visually judge girdle thickness, but the very thick and very thin ones don''t take a lot to understand if you put your mind to it.

girdle.gif
 

lim

Rough_Rock
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Dec 27, 2006
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15
john quixote''s reply was one of the most informative and interesting explanations I''ve read regarding diamond production etc. Thank you.
 
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