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Extremely Thin and Very Thin Girdles

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pyramid

Ideal_Rock
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When consumers are warned away from Extremely and Very Thin Girdles because it may chip, are we talking about minute chips along the girdle maybe occurring or chipping the diamond as in a diamond with a small, medium, large chip?

I know all diamonds can chip I just wondered what the warning covered.
 

oldminer

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When a stone chips, it usually results in a knife-like, very thin area at the site of the initial chip. Then, subsequent chipping can even more readily occur right at the same spot. Before you know it, a small chip can become an important problem. Fixing a small chip is smart.
Waiting for a disaster is not so smart.

Very thin and ext. thin zones heighten the potential for chipping.
 

niceice

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An excellent explanation David... Small chips are similar to small chips that occur in a car windshield, they can spread extensively if not repaired. It is important to note however that while extremely thin and very thin girdles are more prone to damage (especially during the setting process) than thin or medium girdles, that it is possible to damage thin to medium girdles if the diamond is subjected to abuse such as being struck against a countertop, etc.

It is also important to note that diamonds graded as "very thin" by the GIA may have a girdle thickness that would be rated as "thin" on the AGS scale which is why we recommend looking at the girdle thickness as opposed to the vernacular which describes it... We prefer diamonds with a girdle thickness of at least 1%
 

pyramid

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What girdle % would you go for on melee diamonds in the following sizes

0.10 0.15 0.18 0.23
 

oldminer

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I don't use percentage girdles. For durability I'd want all small diamonds to have at least a 32 degree or more crown angle and some girdle thickness beyond knife edge (ext thin). Fine cut diamonds have a crown angle of 33 to 35 degrees, in small stones, and nearly always have faceted girdles. A faceted girdle basically insures there is no knife edge...Or at least not much of any knife edges.
 

pyramid

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I am going to set them in a ring, they would not be liable to chip would they as they look so thin even with a loupe?
 

pyramid

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Oldminer Oh, just checked 1% of a 0.18 carat stone is only 0.037mm. Would this be too thin?
 

Pumpsie

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Feb 19, 2003
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I am considering buying an internally flawless emerald cut stone (2 carat) that has a girdle ranging from extremely thin to thick. I'm concerned that an eventual chip in the "extremely thin" portion will take the stone out of the "internally flawless" range, because, after all, I'm having to PAY for that particular characteristic of the stone.

Any thoughts here? I don't know the crown height % yet...also, after having looked at the stone with a 10X loupe, I couldn't see variation in the girdle, but some portion of it must be "extremely thin" according to GIA.

I know that an appraisal would take care of this, but I'm trying to be as cautious as possible before I buy the stone and pay for an appraisal. Thanks...
 

Pumpsie

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Oh, and Pyramid...didn't mean to butt-in on your post, there...this is just a topic I'm interested in...
 

pyramid

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Oldminer Oh, just checked 1% of a 0.18 carat stone is only 0.037mm. Would this be too thin? The stones will be set in a ring.



(also can anyone answer Pumpsie's questions)
 

pyramid

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Well I went to the jeweller I bought the ring from and they sent it to their chairman who is a gemmologist who said the stone had ideal proportions although I felt it was too thin. When I look at the stone I can just see a very very faint line. CutNut you said that 0.1 mm would be best which on AGS charts comes out at 2.7%. I have read that a diamond from profile view that the crown is about one third of the depth. So I took 60% for depth of 3.7mm which comes out a 2.22mm and then divided by 3 leaving me 0.74mm for the crown. This is probably just rubbish but anyway. I then looked at the stone with a loupe and the girdle looked as though it would fit in so many times and I sort of
worked out the girdle to be about 0.03. I tried looking at 0.1% which meant the girdle width should fit the crown height about 7.4 times well my stone is weigh thinner than that.

I have tried to say to the customer manager that the girdle is I feel too thin but she assures me their gemmologist says it is ideally proportionate to the size of my stone.

I know people recommend appraisers but there is no way I am going into an appraiser about a side stone which is just 0.18mm so I am stuck. I cannot do anything about it either because the jeweller is refusing to budge saying the girdle is proportionate to size but I feel unhappy aboutit.

Also I know that professionals have different opinions but why then is Dave saying anything above 0 is okay. Maybe he has the same schooling as my jewellers chairman. This is the chairman of a national chain store and it is not the worse chain stores but one of the better ones here and I have been told he is a qualified gemmologist. I don't know if they are being genuine which I feel they believe they are or are they lying. I did offer to pay to have the stone set if they swapped it but they wouldn't do that as the stone I have is okay they say.

I am assuming that looking under a 10x loupe a 0.10 mm girdle should look about 1mm well on my stone it looks less than 0.5 mm and less than 0.25mm through the loupe I think.
 

pyramid

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CutNut I am also noticing some A Cut Above superideal cuts in the 23 point mark which have girdles that are 0.7%. Is it that they and Dave believe in AGS cut grades but you believe in the GIA medium for a girdle cut grade?
 

DiehardSearcher

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May 27, 2002
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Whew Pyramid, I read every one of your posts for entertainment purposes.
I love the fact that you will fight to the death on every characteristic of your diamond.

I investigated, made silly assumptions, went way overboard, went way underboard, nit-picked every detail, came up with a year's worth of excuses to continue to turn down stones and keep looking. I finally realized that the perfect diamond is not out there, the perfect girl is. I decided to place my trust in a vendor here to find and sell me a stone that was as close to my specs as he could. Done deal.

If I were selling, I might not sell one to you. Any profits would be eaten up by your unending customer service needs. I would also be very nervous that you would continually be back demanding retribution for a new factoid you learned that your beautiful stone seems to score poorly on.

Pick your diamond and be happy, the diamond itself isn't happiness.
Just my philosphical thought for the day.
 
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