Can GIA be responding to HCA?

[fiftysevenfacets]

Hello All,

I have been working with two B&M establishments for a RB, one of the B&M holds several diamonds on inventory that are considered steep/deep according to HCA. But the other B&M was able to source me two diamonds by GIA that were graded in Nov 10, and Nov 25......They both score a 2.6 and a 2.8 respectively on HCA and are both Ex/Ex/Ex GIA stones.....

I guess my question is, has anyone in the industry kept data records on GIA to see any trend in shifts towards moving away from steep/deep?

 

[FB.]

In the UK (where people only worry about carat, colour and clarity), steep/deep (especially leaning towards very deep, rather than steep) are now very common and make up the vast majority of GIA-Ex cut stones, wherever I look. If buying blind in the UK, I reckon that the average VG will turn out to be almost as attractive as the average Ex.

The prevalence of steep/deep depends on the choices that cutters make. Their choices will be based on supply, demand, what they can "get away with" and the amount of profit.

If you're a cutter, living in these tough times, you can make a steep/deep stone that ticks all the boxes for GIA's top grade and is 1.05ct, so why would you bother to make it into a true ideal that will still not boost the cut grade "on paper", when it will only weight 1.00ct - and the loss of weight will probably cut your profit margin by half?

 

[Todd Gray]

Allow me to answer your question by cracking open the lid on Pandora''s Box:

Do the grading standards of the gemological laboratories dictate what the cutters produce in terms of proportions?

Or do the cutters dictate the parameters which the gemological laboratories rely on to define proportions?

I''m inclined to believe that both factions have direct influence over the other and the sword is sharp on both sides... The laboratories begin with a set of parameters that they feel best define each level of a proportions rating system and they introduce it to the board of directors - which is made up of industry professionals... It''s fair to assume that there are some members of the board who prefer the tighter side of the equation and others who prefer a looser set of parameters, so there is a little tug-of-war and the parameters get bent one way or the other - in my experience, it seems that the proportions parameters have expanded over the years to include a broader range of diamonds which are ''less than ideal'' in response to the cutters ''casting their vote'' via dollars - by directing their production to whichever gemological laboratory makes it easier to obtain a ''paper grade'' which is likely to satisfy most consumers, who are not likely to look beyond the ''paper grade'' of ''Excellent'' to the actual proportions of the diamond.

But hey, I''m probably just guessing

 

[Regular Guy]

My friends above may be responding more about what you should know. Meanwhile, I believe, to your question:

Date: 12/1/2009 10:54:48 AM
Author:fiftysevenfacets
Hello All,

I have been working with two B&M establishments for a RB, one of the B&M holds several diamonds on inventory that are considered steep/deep according to HCA. But the other B&M was able to source me two diamonds by GIA that were graded in Nov 10, and Nov 25......They both score a 2.6 and a 2.8 respectively on HCA and are both Ex/Ex/Ex GIA stones.....

I guess my question is, has anyone in the industry kept data records on GIA to see any trend in shifts towards moving away from steep/deep?

Right now...both GIA''s metric and HCA''s metric are fixed, and neither responds to the other. Differences in output would be based on random variation.

 

[neatfreak]

It just comes back to some GIA Ex cuts really are excellent while some aren't. It's always been that way (at least in recent years).

 

[Todd Gray]

Date: 12/1/2009 12:20:29 PM
Author: Regular Guy
My friends above may be responding more about what you should know.

Correct! And thanks for actually answering the question while I wandered off on a tangent

 

[Rockdiamond]

HI All!

fiftyseven- easy answer here. NO

The HCA is virtually unheard of outside PS.

In terms of deep stones, the basis for which most in the trade would judge a stone to be deep is it''s spread.
A 1.00ct 6.4mm called a "Steep Deep" is someone throwing a name at a stone simply because it does not agree with their personal taste. The lack of photos showing any clear problem proves this point.
Or, if people have looked at the photos here on PS and see a problem, that particular stone is not their taste- but it would not be correct to call a GIA EX cut graded stone "off made" in any way
A 1.00ct spreading less than 6.2mm is deep, and shows it measurably.

FB makes some good points- but remember- at some point the diamond selected "by the numbers" that is to say, purchased based on GIA or AGS report, and no images- at some point a buyer is going to need to approve the stone in person.
If a cutter is producing bad looking stones, or stones with dark centers, they will never be able to be profitable- even if they are "saving weight"