GIA Cut grade question and 2 stone comparison

[angeline]

If a stone 1 has these proportions:

G SI1
Depth: 61.7
Table: 57
Crown: 34.5
Pav: 41
Polish: Very Good
Symmetry: Very Good
8.98-9.07

GIA rate the cut as 'Very Good'. The HCA gives it a 1.9 with it falling inside the GIA EXcellent box on the resulting plot and on the borderline AGS 0 box.

One question I have is does the polish and symmetry affect the GIA cut grade? Why would it fall inside the GIA EX box on the HCA but only get a 'Very Good' from GIA?

and Stone 2 has these proportions:

H SI1
Depth: 61.0
Table: 55
Crown: 34.5
Pav: 40.6
Polish: Excellent
Symmetry: Very Good
8.93-8.99

GIA Cut Grade 'Excellent' HCA is 0.7 and it falls inside both GIA and AGS boxes.

Stone 1 will cost me about $6,200 to upgrade to, Stone 2 will cost me about $8,400 to upgrade to.

Which one would you choose? Stone 2 appears to have the better cut. Is it $2,200 better?

This stuff is so hard! any comments appreciated. I am upgrading from an F SI2 that is ideal cut and is about 8.34mm diameter.

Thank you!

a

 

[oldminer]

I was shown a GIA "Very Good" cut at the recent JCK SHow in Las Vegas. It was NOT a very good diamond in terms of appearance or beauty. Stick with Excellent GIA and you will be more certain of success.

 

[angeline]

Oh. Okay, that seems pretty clear!

Thanks Mr. Atlas! By the way Chris appraised my last stone and I was very happy with his incredibly quick service.

a

 

[angeline]

By the way I ran Stone 1 through the gia Facetware Cut Estimator and it appears that the ''thick'' girdle is what is causing the cut to be downgraded to ''Very Good''.

I might post this as another thread but do you know if a thick girdle will affect performance?

a