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Wriggle Room in Paul Gias Ideal Proportions ?

Texas Leaguer said:
It is not necessary to force everyone to drink the very best tequila. :)
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It's not necessary to force everyone to agree that the tequila you like best is in fact, the best.
As Karl said, define best. There's different views on this Bryan.

I see no one is brave ( or stupid) as me to guess the table size:)
 
Karl_K said:
Define best.
For many(most/all) cutters the best diamond is one that combines high saleability with profitable yields.
GIA EX has raised the bar on the proportion sets for high salability just not to the level that makes many cut nuts happy.
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...then AGS opened doors for the cut nuts to be happy but stalled further cut innovation...., and the rest is history I guess....;-)
 
diagem said:
...then AGS opened doors for the cut nuts to be happy but stalled further cut innovation...., and the rest is history I guess....;)
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Pretty much.
 
diagem said:
...then AGS opened doors for the cut nuts to be happy but stalled further cut innovation...., and the rest is history I guess....;)
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Besides stifling new developments, it also created a far less diverse market, in terms of actual appearance. By putting "traditional" well cut diamonds at a disadvantage.
Many of the best cut carat stones in the 80's and '90's were 6.5mm or close to it.
 
Why are "traditional" well cut diamonds at a disadvantage? They offer a cheaper alternative to ideal and super ideal cuts, for those who find value in them.

It's like saying that reposado and anejo tequila put silver tequila at a disadvantage. They are all available to the consumer, which is a good thing.
 
Yes, I should have been more clear Bryan.
When I said disadvantage I meant that fewer "traditional" well cut diamonds (60/60) will be cut.
I think there's a few reasons why- but the increased depth of the current average would be a main motivation
 
Rockdiamond said:
Yes, I should have been more clear Bryan.
When I said disadvantage I meant that fewer "traditional" well cut diamonds (60/60) will be cut.
I think there's a few reasons why- but the increased depth of the current average would be a main motivation
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I draw my line at 62% depth. I'd prefer my MRB b/t 61.5-61.9%...that just me.
 
Technologies neither in cutting process nor in grading were ever ready for high optical performance diamonds production. The main problem is grading. There is no even technology to grade brightness in accordance to specifics of human vision .
To better understand the problem have a look at 2 images below:
which one will receive higher brightness according to simple raytracing metrics ?
(The clue: It is not enough to take into account just brightness and contrast to grade this phenomena in diamonds correctly.)
which one has higher average brightness?
which one looks brighter for a human eye?

Cutters do not have tools to cut diamonds according to optical performance, LABs do not have technologies to grade diamonds according to optical performance, consumers do not have infrastructure to select diamonds according to optical performance . LABs and trade do mislead consumers when making any statement about super-ideal diamonds.

Screen Shot 2017-07-02 at 08.31.32.png
 
54% of 1 to 1.05ct G VS2 listed on RapNet get GIA Excellent cut.
Most of the population are drinking the best tequila?
It's a bit like the standards applied in schools and sport. Everyone is a winner these days.
David I have no problem calling nicely proportioned 60:60 excellent cuts. There are a very large range of proportions that get HCA under 2 with 60:60 proportions.
I do have a problem with a not for profit org being so lax.
 
Garry H (Cut Nut) said:
54% of 1 to 1.05ct G VS2 listed on RapNet get GIA Excellent cut.
Most of the population are drinking the best tequila?
It's a bit like the standards applied in schools and sport. Everyone is a winner these days.
David I have no problem calling nicely proportioned 60:60 excellent cuts. There are a very large range of proportions that get HCA under 2 with 60:60 proportions.
I do have a problem with a not for profit org being so lax.
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We're in total agreement Garry.
As to why and what all the implications are, it's so complicated. The situation is relatively fluid- over the past 10 years in particular, the changes have been sweeping. Just one of the changes involves a lack of diversity in cutting sites. Both Israel and NYC are basically not feasible cutting centers at this point. I don;t have numbers but the number of carats cut in both places are a tiny fraction of what it was even 10 years back.
GIA is a very "interesting" participant in all this, I agree.
With the new mine to consumer scheme you posted about last week- maybe they're trying to change status to a for-profit corporation.....if that's possible.
There's no denying how consumer friendly the GIA website is. They're aiming at consumers. That might have a role.
 
GIA’s tax status in a distraction. Paying taxes would change their cash flow, but not their business model.
 
We might get in trouble if you all misinterpret my statements ;-)
 
diagem said:
Dancing Fire said: ↑
I draw my line at 62% depth. I'd prefer my MRB b/t 61.5-61.9%...that just me.



I have no problem with over 62% as long as its in the CH :evil:
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Agree, I'd prefer a CH b/t 15-15.7%
 
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