Helium Report question

[satriani]

I was curious about the "Overall Symmetry Quality" rating on these reports. What ratings are available and which is the best and worst ratings that are reported. I''ve seen some with "FR" and "GD" which I assume means Fair and Good. Anyway, now that some stones have this information attached to them I''d be interested in knowing what to look for. Thanks.

 

[Garry H (Cut Nut)]

Give us some links to the reports.

Helium has its own set of symmetry requirements based on things like centers of axes and arc''s

 

[strmrdr]

http://www.goodoldgold.com/Diamonds2005/BR808FSI1-6482905/ILLUSTRATED%20REPORT.pdf

left hand side near the bottom Garry.

 

[satriani]

I''ve been looking at stones from GOG. If it''s not appropriate for me to post links to their site please let me know.

Here''s one report:

http://www.goodoldgold.com/Diamonds2005/BR1170FVS2-6420608/ILLUSTRATED%20REPORT.pdf

 

[strmrdr]

looks like we were posting at the same time.
You can link anything you want from GOG''s website here.

 

[satriani]

Anyone?

 

[Garry H (Cut Nut)]

What is to know?
There are rules about ex and vg etc for symmetry and AGS cut grades.
In the last link posted there is a +1 degree variance that drops this stone to VG

Upper girdle angle, °39.53 38.99 40.28 1.29 - VG
Star angle, °22.70 22.20 23.47 1.27 -VG

This is a very detailed report that is used by manufacturers to monitor their quality control and equipment / process standards.
This stone is very tight, and no one should reject it for this minor facet deviation that would never have been able to be detected with other scanner.

But you were asking about ovals and i could not see any scans of ovals on the website.

 

[satriani]

I think you may have misread my post which asks for a clarification on the abbreviations for "Overall Symmerty Quality" and not oval. All I''m curious about is what levels of overall symmetry are available for this report from best to worst. The only two I''ve seen at this point are GD and FR. This rating is located near the bottom left side of the report like strmrdr pointed out (thanks for that).

 

[strmrdr]

I asked Jon at GOG about it and he said:
"You know how I look at variances?

Helium looks at them too and gives major hits if upper girdle angles, star
angles, and lower half angles are not within certain tight tolerances.

NO diamond, even from the best cutting factories score *excellent* in these
categories."

 

[Rhino]

Thanks for posting my answer to that strm.

Hi Satriani,

First ... like your avatar. I may be going to see Cream at the Garden when they come. U2 this monday.

If you''d like to learn more about "variances" and their relation to the precision of a diamond drop me a pm/email. The particular stone you link happens to be an ultra tight stone with regards to pavilion construction (the mirrors reflecting back the light) which I can teach you more about with the Helium report and our photography/analysis. I prefer not to discuss it here though I am at your disposal if you need me.

Kind regards,

 

[satriani]

Rhino and strm, thanks for the feedback.

 

[Garry H (Cut Nut)]

You are right Satriani, i miss read it all. Sorry.
Is it all clear now?
The comment I made is however where the overall symmetry grade is arrived from.
But it is not that simple as there are ''craftsmanship'' issues and optical performance issues.

 

[satriani]

I think so Gary. You probably summed it up just right. Most of the stones I have focused on seem to have very good to great light performance and ideal proportions (relative to current parameters). But after looking at various diamonds I always find it interesting to see how various reports and evaluations measure things like symmetry, projected performance, etc. With more and more information becoming available I admit that it becomes very easy to get wrapped up and over-analyze things from a buyers end. These days I find myself looking at BrillianceSope, Lightscope, Sarin results plugged into the HCA for the most consistency. GOG had one last week that lined up great across all evaluations, but I was a couple of hours too late in reserving it (oh well).

Since I have your attention I''d be curious to get your thoughts on this stone:

http://www.goodoldgold.com/1_267ct_f_vs1_h%26a.htm

It looks pretty good to me with respect to the cert, BScope and lightscope but I think it takes a small hit on Scintillation and Spread on the HCA and maybe the Helium (just a guess). I''m thinking this might be one of those cases where optical performance and craftsmanship trump the overall stats. What do you think?

 

[Garry H (Cut Nut)]

You are right - you are over analyizing

that is a very fine stone!

 

[valeria101]

Date: 10/9/2005 1:43:13 AM
Author: satriani

These days I find myself looking at BrillianceSope, Lightscope, Sarin results plugged into the HCA for the most consistency.

He he!

That sort of exercise is better left after you''ve got a diamond, if the process happens to leave you with a particular interest in the measurement and grading methods of diamond cuts. I don''t think these tools are precise to such degree that all their measurements be consistent. As is, they need a grain of salt, IMO. It helps to decide beforehand which if any such stats and metrics matter, from your own point of view. GoodOldGold.com dilligently lists allot of the cut quality tests out there - there are others mentioned on this forum even (see AGA at gemappraisers.com, for example) and ISEE2. Neither tool is a perfect ''remote vieweing device'' and if looking for a diamond that ''tops all scales'' may not make sense at all when the potential complementarities and contradictions between the metrics are considered. Fortunately, I don''t think the data needed to take those into account is out there

leaving plenty of room for a bit of fun and practical sense...

I had found the Helium reports on GOG a couple of days ago and the sheer amount of detail made me close the browser window and Pandora''s box ASAP!

 

[Garry H (Cut Nut)]

You have only seen the 1 page reports.
Try the 8 page version, and then you have a real headache

 

[valeria101]

Date: 10/9/2005 6:55:24 AM
Author: Garry H (Cut Nut)
You have only seen the 1 page reports.
Try the 8 page version, and then you have a real headache

Noooooooo, thank you! I am totally confident that other good people are way better at dealing with those. Good grief!

Maybe just a little sample ?

 

[strmrdr]

Date: 10/9/2005 6:55:24 AM
Author: Garry H (Cut Nut)
You have only seen the 1 page reports.

Try the 8 page version, and then you have a real headache

I think there needs to be a 20 page version.
The 8 page one dont have enough info :}
hehehehehehe