Re-Cutting Pavilion and or crown on 4.35 CT

[diagem]

I wouldn't suggest anything blindly but will point some potential issues...

4ct plus is a significant size which might cause pain if something goes wrong in the cutting process. Rare..., but unexpected accidents happen!
I notice "twinning wisps" is the reason for the clarity grade.
This means it could have been a pita to cut or achieve Excelent polish. There may be no guarantees it will achieve that grade again.
And as Paul mentioned...! The cost mentioned by your jeweler will leave you at best in the same level (or maybe slightly above if all goes as planned), but will not bring you to the top cut echelon.

 

[heididdl]

gorgous leave it alone.....

 

[sunlvr]

Thank you all for some very solid advise.

I also found an article on GOG that also talked about HCA scores and the limits of the GIA rounding and how it can affect HCA score, but more importantly use your eyes to determine what looks good.

http://goodoldgold.com/4Cs/NewCutGrading/GIAExAGSIdeal/


That being said, my eyes are not quite what they used to be, and I tend to trust numbers. However, I do know that garbage in equals gabage out. So if I am on the boardline at a 2.7 HCA, but GIA numbers are rounded the 4.35 could actually score a 1.7 if the table angle is really 35.3 degrees and the table % is really 56.5% instead of 57% and pavilion is really 40.7.




So if the above is true then this could be the case and the stone "works".




So long and short of it all, multifactorial interaction in the math and potanital actual stone variation might suggest a stone less than 3.5 on the HCA should be considered "good to look at" and well worth looking at since the variation could make it a 1.7. A stone that is below 3 has the potential to be a HCA 1.7 or a 3.5. A stone that is a 1.7 could be a 3.5, all due to variation and rounding in the GIA measurements.

So unless the stone falls well outside of GIA or AGS Excellent or Ideal classifications (such as a "very good" cut) then HCA is a very helpful tool, but not the end all and all things need to be considered.

Lesson learned. Thank you. The idea of re-ctting this stone seems fruitless and will not achieve much more than potentially damaging an otherwise beautifiul diamond.


I guess to find out the actual proportions, a SARIN report or some other measurement system should be requested to get a better sense of actual proportions beyond the GIA 3X ratings.

I have requested additonal pictures of the H&A and asked if they would by an IS scope and run the tests.

 

[autumngems]

Leave it alone, gorgeous

 

[sunlvr]

So let me through one more out to the group.

The original stone 4.35J SI2

or this stone

3.9 J Si 1 med Blue Fluorescence

Cut of
55/62
34 crown
41 pavilion

HCA of 1.4 (or maybe more)

About same price.

 

[04diamond<3]

honestly, you'll notice a size difference and this other stone seems to have some leakage. Could you get idealscope images for both? That way we could compare better. I do like the number on this second stone better, but I love the size of the first one and honestly, they're both cut well so I'd go for the bigger. Especially if they're the same price.

 

[yssie]

but I love the size of the first one and honestly, they're both cut well so I'd go for the bigger. Especially if they're the same price.

Ditto, since it's pointless to try and judge nuances from GIA's rounded averages, by the numbers (only) the bigger gets my vote too.