More unusual diamond proportions.....

[FB.]

Round brilliant
6.5x3.9mm
1.0ct

Table: 59%
Star: 50%
Crown angle: 33.0''
Crown height: 13.0%
Girdle: med-sl.thk (faceted) (4.0%)
Pavilion depth: 43.5%
Pavilion angle: 41.0''
Lower half: 75%
Polish/symm: Ex/Ex (qualifies for true H&A)
Culet: none

GIA cut grade: Ex
HCA: 1.1 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 1B

Comments?

Thanks,

 

[Lorelei]

Date: 11/12/2009 2:16:58 PM
Author:FB.
Round brilliant
6.5x3.9mm
1.0ct

Table: 59%
Star: 50%
Crown angle: 33.0'
Crown height: 13.0%
Girdle: med-sl.thk (faceted) (4.0%)
Pavilion depth: 43.5%
Pavilion angle: 41.0'
Lower half: 75%
Polish/symm: Ex/Ex (qualifies for true H&A)
Culet: none

GIA cut grade: Ex
HCA: 1.1 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 1B

Comments?

Thanks,

Could be a nice diamond FB if tightly cut, any images? Probably a diamond which would lean slightly more towards brilliance than fire, is that what you are looking for? What is the exact diameter also please and the depth, estimating 6.5 x 6.5mm roughly the depth is around 60.8% thereabouts?

 

[BobR]

FB
1) Per Octonus tables is AGS(0) candidate on proportions and performance
2)) My wife has a similar proportiion 58 table 33.5/41 but 50/80 star /lgf. Its only 0.27ct and is set as part of an earring, we are very pleased with it. In our view it ranks 2nd out of the 6 stones (no 1 has 55 table 32.5 ca/41.4 pa (not steep but deep??) 50/85 star/lgf

 

[stone-cold11]

Not unusual at all.

 

[BobR]

Lorelei's comments match our experience. We prefer our no1 diamond over the no2 (similar proportions to yours) because we have more fire in no1 (our preference) but the 33.5/41 possibly has more brilliance

 

[FB.]

Date: 11/12/2009 2:44:31 PM
Author: Stone-cold11
Not unusual at all.

Perhaps I should have said; unusual for a stone to have such a large table and flat crown, yet manage to qualify for an exceptionally high cut grade.

 

[FB.]

Lorelei & Bob

Yes, more brilliance and less fire was what I expected to hear, but HCA still rates fire as "excellent", which surprised me. I would have expected good or very good fire; not excellent.
The HCA doesn't take into account minor facets, but I suspect that the large table and average star size would impair fire somewhat.
I was expecting more negative comments on the relatively flat crown.

 

[FB.]

Date: 11/12/2009 2:16:58 PM
Author:FB.
Round brilliant
6.5x3.9mm
1.0ct

Table: 59%
Star: 50%
Crown angle: 33.0''
Crown height: 13.0%
Girdle: med-sl.thk (faceted) (4.0%)
Pavilion depth: 43.5%
Pavilion angle: 41.0''
Lower half: 75%
Polish/symm: Ex/Ex (qualifies for true H&A)
Culet: none

GIA cut grade: Ex
HCA: 1.1 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 1B

Comments?

Thanks,

...and then compared to the following stone:

Round brilliant
6.35 x 4.0mm
1.0ct

Table: 54%
Star: 50%
Crown angle: 36.0''
Crown height: 16.5%
Girdle: med-sl.thk (faceted)
Pavilion depth: 42.5%
Pavilion angle: 40.6
Lower half: 80%
Polish/symm: Ex/Ex
Culet: none
GIA cut grade: VG but borderline EX
HCA: 1.9 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 2A

What really surprises me is that the HCA score for this FIC is 1.9, yet it only gets Gd for spread, VG for light return/scintillation and EX for fire.
The other BIC-cut-stone (HCA 1.1) gets VG for spread, EX for everything else.

Both fall within HCA 1-2, but the flatter (BIC) stone''s HCA outputs give the impression of being better because it has more "Excellent" categories.

 

[Lorelei]

Date: 11/12/2009 3:38:56 PM
Author: FB.

Date: 11/12/2009 2:16:58 PM
Author:FB.
Round brilliant
6.5x3.9mm
1.0ct

Table: 59%
Star: 50%
Crown angle: 33.0'
Crown height: 13.0%
Girdle: med-sl.thk (faceted) (4.0%)
Pavilion depth: 43.5%
Pavilion angle: 41.0'
Lower half: 75%
Polish/symm: Ex/Ex (qualifies for true H&A)
Culet: none

GIA cut grade: Ex
HCA: 1.1 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 1B

Comments?

Thanks,

...and then compared to the following stone:

Round brilliant
6.35 x 4.0mm
1.0ct

Table: 54%
Star: 50%
Crown angle: 36.0'
Crown height: 16.5%
Girdle: med-sl.thk (faceted)
Pavilion depth: 42.5%
Pavilion angle: 40.6
Lower half: 80%
Polish/symm: Ex/Ex
Culet: none


GIA cut grade: VG but borderline EX
HCA: 1.9 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 2A

What really surprises me is that the HCA score for this FIC is 1.9, yet it only gets Gd for spread, VG for light return/scintillation and EX for fire.
The other BIC-cut-stone (HCA 1.1) gets VG for spread, EX for everything else.

Both fall within HCA 1-2, but the flatter (BIC) stone's HCA outputs give the impression of being better because it has more 'Excellent' categories.

Fiery Ideal Cuts often get good for spread, sometimes these diamonds have extra weight in the depth and crown, hence the HCA spread rating. Usually stones which have 60.3% or less for depth get Ex for spread on the HCA.

 

[yssie]

Date: 11/12/2009 3:43:42 PM
Author: Lorelei

Date: 11/12/2009 3:38:56 PM
Author: FB.

Date: 11/12/2009 2:16:58 PM
Author:FB.
Round brilliant
6.5x3.9mm
1.0ct

Table: 59%
Star: 50%
Crown angle: 33.0'
Crown height: 13.0%
Girdle: med-sl.thk (faceted) (4.0%)
Pavilion depth: 43.5%
Pavilion angle: 41.0'
Lower half: 75%
Polish/symm: Ex/Ex (qualifies for true H&A)
Culet: none

GIA cut grade: Ex
HCA: 1.1 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 1B

Comments?

Thanks,

...and then compared to the following stone:

Round brilliant
6.35 x 4.0mm
1.0ct

Table: 54%
Star: 50%
Crown angle: 36.0'
Crown height: 16.5%
Girdle: med-sl.thk (faceted)
Pavilion depth: 42.5%
Pavilion angle: 40.6
Lower half: 80%
Polish/symm: Ex/Ex
Culet: none




GIA cut grade: VG but borderline EX
HCA: 1.9 (also possible AGS 0 ideal cut candidate, according to the HCA table)
AGA: 2A

What really surprises me is that the HCA score for this FIC is 1.9, yet it only gets Gd for spread, VG for light return/scintillation and EX for fire.
The other BIC-cut-stone (HCA 1.1) gets VG for spread, EX for everything else.

Both fall within HCA 1-2, but the flatter (BIC) stone's HCA outputs give the impression of being better because it has more 'Excellent' categories.

Fiery Ideal Cuts often get good for spread, sometimes these diamonds have extra weight in the depth and crown, hence the HCA spread rating. Usually stones which have 60.3% or less for depth get Ex for spread on the HCA.

Pretty much my proportions, my table is 54.7

My last stone was a shallow combo (33.5/40.6, 60.1d 58t). I definitely notice more fire from this one - the difference shocked me the first time I pulled it out of the box. This stone also doesn't go dark when I lean over it. Both my old and current stones are GIA VG, yet they're so different in personality! My current is 2ct but spreads 8mm exactly, so quite a bit less than ideal... it doesn't bother me, but I imagine I'd find it irksome if I hadn't gone in specifically wanting an FIC.