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What''s a more reliable?

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johnnyj11

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On the dimensions of the stone (mm), what''s more reliable, a GIA report or a Sarin?
 

JulieN

Super_Ideal_Rock
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you are aware that GIA rounds?

So if the Sarin numbers fall within the GIA rounding numbers, I might go with the Sarin. If the Sarin is outside of GIA rounding, I'd go with GIA.

Oh. mm. Surely it can't be off that much.
 

RockDoc

Ideal_Rock
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Aug 15, 2000
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It depends on which report of the Sarin you''re looking at.

See if you have the MNF page, where the facets are individually reported.

GIA reports an average on some facet groups and then they round up. For the table they round up from the greatest table measurement.

If you just have a sarin report that just says crown angle, that is averaged but not rounded up. Ask for the MNF page.

Rockdoc
 

diagem

Ideal_Rock
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Date: 1/11/2007 12:18:19 AM
Author:johnnyj11
On the dimensions of the stone (mm), what''s more reliable, a GIA report or a Sarin?
In mm. measurements..., i have witnessed both GIA and Sarin come up with wrong #''s
It depends greatly on specific shapes (obviously rounds will be more accurate!!!)
On Fancy shapes, both miss the numbers (minimally) quite often.
 

diagem

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I just had a classic example from a couple of days ago...
I purchased an emerald cut that had a GIA report that read 74% table.

I retouched the table on the cutting wheel for the only reason minimize the table %.
I re-polished the steps on the crown to get a 67-68% table.

I re-submited the diamond for a new report, and sure enough the GIA returned us the diamond with the same exact #''s.
Which means to me that they just copied the numbers from the old report to the new one...

I just asked for a re-check, and am waiting to hear their comment.

I guess no one is perfect including the GIA!!!
 

oldminer

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GIA use Sarin machines for measuring. So, the answer to the question is they are both the same. There are new and old versions of Sarin output floating around. The addition of the length of upper and lower girdle facetsand greater details on other facets in the newer output helps the predicitve model makers to do their magic. I find the old version adequate since we directly measure light output and only require the basic measurements to assist in stone identification and cut quality grading.

When a consumer gets highly detailed number sets they will get lost in the minutiae of the numbers and fail to get good information about how well the diamond looks or does not look. Lots of data might be considered a friendly smokescreen of sorts. The important thing about a diamond is not its numbers, but its beauty.
 

diagem

Ideal_Rock
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Date: 1/11/2007 2:53:40 PM
Author: oldminer
GIA use Sarin machines for measuring. So, the answer to the question is they are both the same. There are new and old versions of Sarin output floating around. The addition of the length of upper and lower girdle facetsand greater details on other facets in the newer output helps the predicitve model makers to do their magic. I find the old version adequate since we directly measure light output and only require the basic measurements to assist in stone identification and cut quality grading. How does GIA/Sarin measure out-of-the-ordinary or speciality cuts?

When a consumer gets highly detailed number sets they will get lost in the minutiae of the numbers and fail to get good information about how well the diamond looks or does not look. Lots of data might be considered a friendly smokescreen of sorts. The important thing about a diamond is not its numbers, but its beauty. SO TRUE!!!!!
 

oldminer

Ideal_Rock
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The truly unusual shapes are not measured by a Sarin or Ogi device. Some features can be measured digitally, but others must be mechanically measured. These devices have limitations on which shapes they can handle.
 
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