AGS and Sarin results

[drcoll]

I was wondering which is the most accurate:

The dimensions given on the ASG certificate or the Sarin results

I was browsing through some certificates at niceice.com and there seems to be conflicting dimensions.

An example is at the following link: http://www.niceice.com/certcopies/images/0721hvvs1_ags2629506.jpg

The pictorial view on the ASG gives:
Table 55% Depth 61.3% Crown >34.6 Pavilion >40.9 which gives a HCA of 0.9

The Sarin results shown are:
Table 56% Depth 61.3% Crown >34.5 Pavilion >40.8 which gives a HCA of Fish Eye – Do Not Purchase!!!!

Would this be due to faulty equipment, measurements from differing locations, a mistake or am I missing something?

 

[oldminer]

All the major labs use Sarin machines. the errors are inherent, to some extent, within the accuracy of the Sarin itself. Also, labs have slightly tweaked programming that allows decimal points, rounding, etc. All in all, they devices is reasonably accurate enough, but not perfect for sending a space ship to a distant star.

 

[pricescope]

Hi Drcoll,

34.5 - 40.8 degrees crown and pavilion angles cannot produce fisheye. Make sure you are selecting degrees, not %.

AGS is using Sarin machines as well. 0.1 degree measurement error is within Sarin accuracy.

 

[lawmax]

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On 4/4/2002 8:27:48 AM


The Sarin results shown are:
Table 56% Depth 61.3% Crown >34.5 Pavilion >40.8 which gives a HCA of Fish Eye – Do Not Purchase!!!!

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I think you may have made a mistake when you put these numbers into the cut adviser. It gives a score of 1.0 TIC, Ex, Ex, VG, VG, Ex, TIC

 

[drcoll]

Thanks my mistake!!!

Although there is a difference HCA 1.0 and 1.3
Would you suggest an average is taken in such cases?

 

[pricescope]

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On 4/4/2002 8:55:42 AM

Thanks my mistake!!!

Although there is a difference HCA 1.0 and 1.3
Would you suggest an average is taken in such cases?


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1.0 and 1.3 are great scores. This is Tolkowski ideal cut stone. Once HCA is lower than 2 you shouldn't worry about HCA anymore.

"A score below 2 (Excellent) means you have eliminated known poor performers (more than 95% of all diamonds). Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5."

 

[elton]

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1.0 and 1.3 are great scores. This is Tolkowski ideal cut stone. Once HCA is lower than 2 you shouldn't worry about HCA anymore.

"A score below 2 (Excellent) means you have eliminated known poor performers (more than 95% of all diamonds). Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5."
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Why is this? Is it because differences between any lower scores isn't easily distinguishable w/ the naked eye?

(It's a good thing for me- the stone I got rated a 1.5 or 1.6 on the HCA).

-elton

 

[pricescope]

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On 4/5/2002 6:03:01 PM

Why is this? Is it because differences between any lower scores isn't easily distinguishable w/ the naked eye?

(It's a good thing for me- the stone I got rated a 1.5 or 1.6 on the HCA).

-elton

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The difference can be in relationship between white and colored light, minor facets, static and dinamic contrast, amount of head reflection, etc.