GOG just got new larger Octavias

[debi1960]

To Kenny-

I do know that the Asschers do face up smaller than rounds. The round that I was looking at for size was between 1.35-1.50. I think the Octavia Asscher 1.57 will be similar. I will also look at the 1.60 that is not yet rated by AGS.

 

[diagem]

Date: 3/17/2010 5:56:01 PM
Author: Karl_K

Date: 3/17/2010 5:45:33 PM
Author: DiaGem
Karl, what are the AGS spread parameters/limitations based on? Do you know?

It is arbitrary as far as I know for fancies.
For rounds it is based on tolk.

No wonder AGS has a problem grading aliens

.
We know Octavia is not the only new cut-design AGS has a problem grading as its grading cant be based on acceptable generic proportions.

 

[kenny]

Is anyone at liberty to repeat what AGS people said when they saw the Octavia? - certainly nothing on the record or offical, just passing personal comments . . .

 

[diagem]

Date: 3/17/2010 7:07:36 PM
Author: kenny
Is anyone at liberty to repeat what AGS people said when they saw the Octavia? - certainly nothing on the record or offical, just passing personal comments . . .

If I had the info I would gladly share..., I dont know if Rhino (he submitted them) has the liberty as per PS policies.
What I did understand on Karl''s earlier comment "...Losing the 1/2% to 1% just because they are .02ct and .05ct to heavy for the diameter for ags0..." it seems to me that AGS compares the spread factor vs. generic square emerald cut designs. Octavia cant be compared to SE or Asschers..., its a custom design!

One thing is pretty much certain IMO..., most Diamonds cut to the AGS0 grade were/are cut to specifically achieve the 0 grade.
Octavia was designed & cut to achieve both maximum light performance & maximum beauty within our taste and experience for this design.
Octavia was not cut to achieve the AGS0 grade..., but the results are not surprising

 

[Rhino]

My thoughts exactly when designing the AVR's and AVC's.

I wasn't cutting them for an AGS Ideal or even a GIA Ex grade. While numbers and geometry are important in producing the final product they take a back seat to what actually produces the beauty they attain. There was a certain appearance they had to have with regards to brightness, contrast, fire and sparkle based on my personal experience of hand picking diamonds for light performance for close to a decade now via the best technologies available for analysing this phenomena and corellating that data with practical observation. When we first sent the AVR's to GIA they were grading them as modern rounds. Modern rounds with 48-52% tables, crown heights around 20% and lower girdles at the length I am purposely having them cut to acquire the beauty they have will not make a GIA Ex grade (VG at best) and that is perfectly fine. I was perturbed to see them grading them like everyday modern rounds because they aren't but was pleasantly surprised to see AGS accurately describe them for what they are ... Old European.

If AGS takes the time to research Old European's and for that matter Old Mine's (the AVC's) I firmly believe they will arrive at the same conclusions I did with regards to their beauty. At the end of the day it boils down to researching and taking the time & capital to cut those combos that can and will produce the rarest optics.

If losing weight more weight means sacrificing beauty on an Octavia I say leave it be. There's nothing wrong with it. If you can figure out how to keep the same opticsa and get more spread ... of course that's cool too but I don't see how you can do that at this point.

My .02c

All the best,

 

[Stephan]

Jonathan,
What I ask myself when screening your AVR collection is:
Why combine ~41.2 pavilion with ~35.0 crown. Wouldn''t 40.8-34.5 work?
This is not a criticism, just a question.

 

[Karl_K]

Date: 3/18/2010 3:02:45 AM
Author: QueenMum
Jonathan,

What I ask myself when screening your AVR collection is:

Why combine ~41.2 pavilion with ~35.0 crown. Wouldn't 40.8-34.5 work?

This is not a criticism, just a question.

No it wouldn't...
In an oec the mains push the lower girdle facets out from under the table changing the angle relationships in the diamond.
Which is why RB grading/numbers will not work on them.

This is some what explained in my article here:

http://journal.pricescope.com/Articles/68/1/Do-the-pavilion-mains-drive-light-return-in-the-modern-round-brilliant.aspx

 

[Karl_K]

Here would be the results....
The donut effect from to much obstruction

 

[Stephan]

Thank you Karl!
I really should buy Diamond Calc...