HCA charts now have new AGS Candidates

[Garry H (Cut Nut)]

When you use https://www.pricescope.com/cutadviser.asp the HCA adviser now, you will notice the chart has a squiggly white central overlay.

This zone will include diamonds that if cut in the normal way (with balanced minor facets etc), and ideal symmetry and polish, then the stone should qualify for AGS 0 or aGS ideal.
They call this a guide for ''Candidates''. It is not a grading per se''.

Note too that diamonds with especially good combinations of minor facets and perhaps some with creative ''indexing'', may fall outside this white zone and still achieve AGS 0 grading from the lab.

Because HCA charts were not ever done below 53%, the HCA charts from 47% to 52% are the same 53% ones. But the AGS overlays are correct for each of those table size ranges.

(AGS have slightly different results for 4, 6, 8, 10 and 12mm - we have done these overlays for 6mm or about 0.90ct)

 

[belle]

thank you garry. i think many will appreciate the new overlay. it''s good to know that you are keeping up with changes and that this tool is evolving.

 

[kenny]

Yes, indeed!
Thank you for doing what you do Garry.
Not just the invaluable HCA and Idealscope, but your "Get to the truth no matter what!" style.
You are the ultimate consumer advocate!

The world is getting better diamonds because of you.
Thank you.



I think you do more for the industry than just about anyone else here.
You increase consumer education and our comfort level, which has to increase sales or push us up into better stones.

 

[Regular Guy]

I concur with my colleagues, Garry. I''d seen the overlay in the last couple of days, and figured I was just behind the times, with it having been up a while.

Thanks for helping to keep us current, and for your sharp edge.

 

[Maxine]

Garry, this is fascinating.....have been playing w/some numbers and noticing some interesting things here......

 

[MissAva]

Wow! thanks for taking such good care of us Garry!

 

[Garry H (Cut Nut)]

Thank you for your kind words

 

[perry]

Thanks Gary:

It will be interesting to redo my calc''s and locate the position for the diamonds I own. Me suspects that they are either in or close.

Perry

 

[Giangi]

This is neat, Garry! I like how your tool is evolving on par with new researches/studies/standards.

 

[Regular Guy]

Garry,

1) I see in the last 2 days changes in the patterning of the AGS chart. Still understanding how their suggested proportions play out? (edited to add....no....change that....I guess there's no change at all. What I had done today was enter the prortions of my diamond (62, 55, 35.8, 40.1) then saw the AGS overlay, and noticed it was different than the view I'd seen the previous day with the default parameters left in the chart (60, 57, 34, 40.5)...I somehow hadn't realized the range of crown & pavilion's changes on your chart, as table & depth changes, too. But, of course it does!

2) Any single thing, or combination of things -- as far as their fundamental set of controls (such as assumed viewing distance, for example) that you would primarily point to, to understanding why AGS's smaller set of good results hangs north of the center of your range of successful combinations?

Thanks in advance!

 

[Iceberg]

Well said Ira Z., I was wondering the same. Nice changes in the HCA chart and, much appreciated but, a tad more info would be nice. In the example, a .4 (overal excellence) falls outside AGS''s ideal box thing-a-jigger. Why is that so ?

I thought that, from the write-up on HCA, the more in the red zone, the better...hummm. The .4 sure is and yet it falls ''outside the circle of trust''. Who''s really thinking outside the box ? HCA or AGS ?


Thanks Garry.

Paul

 

[Garry H (Cut Nut)]

AGS believe that a good diamond should be able to sustain 40 degree of obstruction.
That is like a 6 inch head looking from 8 1/2 inches obstructing light.

This is what you would see with the blue ASET set at 40 degrees.

AGS say that all good stones should not have these "club feet" on the outer star.
I disagree because once you buy a stone you would never look from that close up.
And the 2-3 % bigger spread is a bonus for this default stone.

 

[mdx]

Date: 9/16/2005 4:57:50 PM
Author: Garry H (Cut Nut)
AGS believe that a good diamond should be able to sustain 40 degree of obstruction.
That is like a 6 inch head looking from 8 1/2 inches obstructing light.

This is what you would see with the blue ASET set at 40 degrees.

AGS say that all good stones should not have these ''club feet'' on the outer star.
I disagree because once you buy a stone you would never look from that close up.
And the 2-3 % bigger spread is a bonus for this default stone.

Good one Gary , Very nice practical answer

Johan

 

[hoorray]

Very nice addition. It''s nice to see how the new grading system applies with a tool we already know and use.....

Thanks for the update.