When the proportions say ideal, but the performance doesn''t agree...

[Regular Guy]

...what do you do?

a) as the cutter?

(do you know because of reflector technologies, experience?...and how do you know how to make repair)?

b) as the dealer/cutter/wholesaler charged with sending the diamond to a grading agency?

(any reason not to send to AGS, hoping for a zero or 1, and failing that, requesting gold)?

c) as a shopper
(any meaningful clues apart from reflector technologies, in advance of seeing the stone?)

...and how frequently is this an issue

(understanding if it is your one in 100...it is no less of a problem than if it's one in 5...but is it one in five?)?

 

[oldmancoyote]

Date: 3/27/2009 5:35:32 PM
Author:Regular Guy
c) as a shopper
(any meaningful clues apart from reflector technologies, in advance of seeing the stone?)

...and how frequently is this an issue

(understanding if it is your one in 100...it is no less of a problem than if it''s one in 5...but is it one in five?)?

Price out of line as a signal? Talk to the vendor (assuming high level of trust and availability of alternatives i.e. vendor has not bought the stone for stock)?

No idea how frequent this is. If I were to guess, I''d say closer to 1 in 100 than 1 in 5 for rounds. Way more for fancy shapes.

 

[Rhino]

Date: 3/27/2009 5:35:32 PM
Author:Regular Guy
...what do you do?

a) as the cutter?

(do you know because of reflector technologies, experience?...and how do you know how to make repair)?

Most cutting facilities do not cut with reflector technologies. They try to stay within the boundaries of whatever grade they''re trying to attain generally. Interestingly though, even keeping within the numbers isn''t a guarantee as those numbers only reflect slope angles (facet angles cut in the north/south orientation). I''ve seen diamonds with "Ideal" numbers (slope angles) but wonky azimuth angles (angles cut in the east/west orientation) that cause seemingly ideal numbers to not have ideal light performance.

b) as the dealer/cutter/wholesaler charged with sending the diamond to a grading agency?

That cost is generally factoried into the overall pricing.

(any reason not to send to AGS, hoping for a zero or 1, and failing that, requesting gold)?

Exactly. One reason why lots of facilities do not submit to AGS. AGS is trying to open more options to garner more business. I understand their strategy.

c) as a shopper
(any meaningful clues apart from reflector technologies, in advance of seeing the stone?)

AGS PGS with a Helium scanner or top of the line Sarin leaves no room for doubt but that is just AGS'' system. Some of us have personal cut offs even within that system.

...and how frequently is this an issue

(understanding if it is your one in 100...it is no less of a problem than if it''s one in 5...but is it one in five?)?

I deal with quite a number of H&A factories and I do not and would not blindly put my seal of approval on any particular brand. Those factories that have been around longer will generally cut a good consistent product but never 100%.

All the best,

 

[strmrdr]

define ideal

 

[Regular Guy]

Date: 3/27/2009 6:05:22 PM
Author: strmrdr
define ideal

We could use the norm of performance that is consistent with what we have come to regard as especially favorable reflector images. Storm...you could come up with other coincident markers. We just want to try to say, for outstanding performance, where proportions have been markers...lets not trust them, and see backwards how good they really are to begin with. We could even rely on the AGS system of evaluation for zero, do bayesian analysis, and say, given a round''s imputed ideal performance, what is the likelihood that correlated proportions would have predicted it.

 

[strmrdr]

I think there are to many variables to try and define the odds of any given number set being a top diamond.
Particularly if you take optical symmetry into account which the labs do not consider.

I think that AGS0 Plat/3D should at least guarantee a nice diamond but not always a top end one like we are used to from the top ps dealers.
AGS Gold Ideal and GIA EX have a much lower confidence level as a 2d system can never be used for selection.
2d is for rejection only at best!

My message is simple....
Give me images and I will buy don''t give me images then you don''t want my business.

 

[Regular Guy]

don''t forget (a) and (b)...

Date: 3/27/2009 5:35:32 PM
Author:Regular Guy

When the proportions say ideal, but the performance doesn''t agree...

...what do you do?

a) as the cutter?

(do you know because of reflector technologies, experience?...and how do you know how to make repair)?

b) as the dealer/cutter/wholesaler charged with sending the diamond to a grading agency?

(any reason not to send to AGS, hoping for a zero or 1, and failing that, requesting gold)?

 

[strmrdr]

a and b...
a: As long as they get gia EX they would likely do nothing.
Both gia and AGS will recommend what would needs to be done to get a higher grade.


b: send it to the lab that provided the best return for the stone.

 

[Lorelei]

Date: 3/27/2009 11:07:18 PM
Author: strmrdr
I think there are to many variables to try and define the odds of any given number set being a top diamond.
Particularly if you take optical symmetry into account which the labs do not consider.

I think that AGS0 Plat/3D should at least guarantee a nice diamond but not always a top end one like we are used to from the top ps dealers.
AGS Gold Ideal and GIA EX have a much lower confidence level as a 2d system can never be used for selection.
2d is for rejection only at best!

My message is simple....
Give me images and I will buy don''t give me images then you don''t want my business.

Ditto!

 

[oldminer]

I think all cut to what passes and Excellent or Ideal standards have high potential to look very fine. However, not every single diamond is cut the same because there are many small nuances which are not incorporated into the "standards" placed before the cutter to adhere to. Jonathan and others have mentioned that there are little things which have an overall effect which creates non-positive results.

I use a digital tool for direct assessment of how each diamond works with light. It does not look at any of the angles or dimensions, but responds based only on analysis of the light performance. A great diamond scores high and a lesser stones scores lower. Within the top six of eleven grades there is little to no eye visual difference in beauty or performance. This follows the traditional grading strategy of color and clarity where the top range of grades are virtually the same to the naked eye, yet the dollar variation is quite substantial. After one analyzes light performance, one ought to then look at the durability, relative size for weight, and polish/symmetry factors in order to determine if the performance of the diamond and its craftsmanship attributes all ad up to a top cut diamond. There are many diamonds which perform very well yet are not so well fashioned. The opposite holds true, too. There are diamonds which measure up by parameters yet fail to be visually in the top categories of performance/beauty.

Giving credit to the skill of certain cutters or to the quality control of some brands is allowable. For example, when you review an ACA or HOF type stone, or when you know the diamond is a top cut from a cutter such as Infinity, you can know by the measures or the brand that the diamond is very likely to "work" at the top end of quality. There are many pretenders and many other excellent cutters. Reflector tools can prove performance pretty well, but the judgment remains subjective. Proportions tell a part of the story, but can't do the entire process at a 100% level.

 

[strmrdr]

Date: 3/28/2009 1:53:05 PM
Author: oldminer
Proportions tell a part of the story, but can't do the entire process at a 100% level.

I think that should be a given that no one tool holds all the answers.
Each is a piece of the puzzle.
I would say that less than 50% of the factors that influence diamond beauty are understood right now and out of the 50% only 1/2 or 25% of the total are well documented.

 

[Dancing Fire]

Date: 3/27/2009 6:05:22 PM
Author: strmrdr
define ideal

IMO...no wild variance b/t any of the specs,plus favorable reflector images.