DiamCalc Request - Please Assist Me. Thank you!!

[phiberoptik]

I have tried to download DiamCalc a couple times with no luck. The evaluator said No to me so I wondered if someone else could run it for me. I downloaded the viewer so even if I could get the diamcalc file to view with Gem Adviser that would be cool...

Thank you to anyone who can do this for me.



Report Type: GIA Diamond Dossier®

Date of Issue: July 13, 2007

Laser Inscription Registry: GIA 16023869

Round Brilliant

Measurements: 5.98 - 6.01 x 3.67 mm

Carat Weight: 0.81

Color Grade: F

Clarity Grade: SI1

Cut Grade: Very Good

Proportions:

Depth: 61.2 %

Table: 56 %

Crown Angle: 35°

Crown Height: 15.5 %

Pavilion Angle: 40.4°

Pavilion Depth: 42.5 %

Star length: 50 %

Lower Half: 80 %

Girdle: Thin to Slightly Thick, Faceted

Culet: None

Finish:

Polish: Excellent

Symmetry: Very Good

Fluorescence: None

Clarity Characteristics: Feather, Twinning Wisp

 

[JohnQuixote]

Hi Phiber.

This info won''t produce a DiamCalc prediction any more useful than the HCA score. The CA, PA and minor facet measurements are averages of multiple numbers (crown angle 35 is an average of eight measurements for example). Cut precision, girdle details and optical symmetry variations aren''t accounted-for. All we could do with this data is create a sim of perfect wire-frame symmetry with many improvisations and assumptions. Although that would be a nice picture it would not be representative - and could be misleading. An actual ideal-scope or ASET image will allow more meaningful input.

A general comment: In some cases a PA that low could have issues, but not always.

 

[Garry H (Cut Nut)]

the free trial DC will only work with a marquise model.
Gem Adviser free viewer will only work with a real 3D model from a scanned diamond.

Modelling from these proportions will not help you more than this http://www.octonus.com/oct/products/3dcalc/adviser/is/
It can take a while to download the many images

 

[Serg]

Date: 11/19/2007 3:32:45 PM
Author: Garry H (Cut Nut)
the free trial DC will only work with a marquise model.
Gem Adviser free viewer will only work with a real 3D model from a scanned diamond.

Modelling from these proportions will not help you more than this http://www.octonus.com/oct/products/3dcalc/adviser/is/
It can take a while to download the many images

re:Gem Adviser free viewer will only work with a real 3D model from a scanned diamond.

Gem Adviser free viewer will work with ANY Diamcalc file. You will able see any 3D model which had been saved in Diamcalc

 

[JohnQuixote]

I forgot to bookmark that link when I saw it before Garry - thanks for bringing it up again.

Hi Serg. Great work. One thought... at the bottom of the page it says The real diamonds are not ideally symmetrical so it is preferable to use the real 3D-model even for prior analysis.[/i] >>

Maybe this footnote should use the words "perfect symmetry?" In many places "ideal symmetry" would be interpreted as a finish grade from AGS, which has nothing to do with the optical symmetry you refer to here.

 

[phiberoptik]

Thank you for the replies.

John, Garry, or whomever, what do I need to be looking for when I see the diamond in person. HCA gave it all EX and a VG for spread. It sounds like there isnt much else I can do as far as the science of the diamond, but when I go to look at it, how am I to tell if it is performing as well as HCA says it should, compared to a lesser quality diamond. I mean I can naturally see the difference between a junk diamond and an ideal one, but comparing this one and one similar... how can I tell if Im getting a solid performing diamond?

Thanks for the education guys (and any ladies who wish to partake!)

 

[phiberoptik]

Oh and Garry thanks for the link. Even those basic characteristics are almost identical to this diamond. 56% table and 6mm with pointed cutlet. Only difference is the thin-sl. thick girdle vs. the models'' medium girdle.

Now how do I compare the model to the real image Ill see tomorrow?

 

[JohnQuixote]

Date: 11/19/2007 4:15:40 PM
Author: phiberoptik
Oh and Garry thanks for the link. Even those basic characteristics are almost identical to this diamond. 56% table and 6mm with pointed cutlet. Only difference is the thin-sl. thick girdle vs. the models'' medium girdle.

Now how do I compare the model to the real image Ill see tomorrow?

The 40.4 pavilion is slightly shallower than the "bullseye" for pavilion angles you''ll see most-often discussed here.

See this page (HCA information)

i]>>

View the diamond in several light sources. Compare it to one with a similar or slightly lower crown angle, but with pavilion angle in the 40.6-41.0 range. Check to see if the 40.4 appears darker by comparison, particularly when viewed close up. Be realistic - any diamond will get pretty dark if you glue your eyeball to it - common viewing distance for normal wear can be considered 10-24 inches.

 

[phiberoptik]

Thank you John. I am looking forward to seeing the IS image as well seeing as GIA only graded it a VG but the 40x picture looked better than some ideal diamonds I have seen.

I will see what they have to compare it to.

Thanks

Any other suggestions?

 

[JohnQuixote]

Date: 11/19/2007 5:28:07 PM
Author: phiberoptik
Thank you John. I am looking forward to seeing the IS image as well seeing as GIA only graded it a VG but the 40x picture looked better than some ideal diamonds I have seen.

I will see what they have to compare it to.

Thanks

Any other suggestions?

No prob. The reason GIA gave it a VG in cut is the 40.4 PA. They don't allow any combos < 40.6 in EX. This is logical since they used more obstruction (the shadow/darkening effect I referred to above) than some other metrics.

AGS predicts this combo to be a borderline AGS0-AGS2 in light performance depending on particulars. That's why a diamcalc sim based on assumptions won't help, you need to see it live... If sent to AGS it might earn 0 in light performance - or 1 - or 2. It's great that you get to use your actual eyes tomorrow.

 

[phiberoptik]

Actually... here it is...

http://www.jamesallen.com/diamonds/F-SI1-Ideal-Cut-Round-Diamond-1111569.asp?b=16&a=12&c=77&cid=131

You can look at the magnified view of it there.

 

[Garry H (Cut Nut)]

Optically symetrical.
Enter the numbers into HCA and then read the HCA warning about slightly shallow stones looking a bit dark when seen from very close up.
I prefer them because they show the dirt less, and look very bright when you are wearing them

 

[phiberoptik]

Garry, did you follow the link and take a look at the diamond yourself? Id be interested to see your thoughts of the actual diamond.