Questions on Opinions on diamond color in the diamond industry.

[strmrdr]

Lets concentrate on color because it is the hardest area for consumers to judge for themselves on which color grade the diamond actually is.

You buy a diamond and the cert that comes with it says its G color, your appraiser says it is G color, and your trusted vendor says it is G color is it in fact a G color diamond?
The answer is NO you have several opinions that it might be a G colored diamond but you don't know it for a fact.

Is this harmful to consumers?
Some in the industry will reply that this is how we have done it for a very long time and it works.
My question would be works for who?
Is todays G color diamond the same color as a G color diamond of 10 years ago and will it be the same color as one 10 years from now?
The future of diamond grading is impossible to predict but due to changes in the lighting conditions and other issues that have taken place in recent years it is entirely possible that a G color diamond from 10 years might get graded higher or lower today.
With thousands of dollars riding on what grade it is an important issue.

Will machine grading help in this area?
Long term I think so if the machines are accurate and repeatable and get accepted by the industry it will help a lot.
Short term it doesn't help with the question of just what color a G color diamond is supposed to be.
How do you set the scale on your machine when the scale varies depending on who you ask?
Will the industry accept the scale the machine manufactures set?
I don't know the answer.

What are some other solutions to the problem?
I don't know.

Disclaimer: The above is my opinion gained from reading and learning from what others have written. I have more questions than answers and am posting this seeking answers.
I have stated my answers and they may or may not be correct.
This started out as an article for the journal but I found that there are too many questions I don't have answers too for it work in that format.
In the future I may get enough information to make it an article or if anyone wants to tackle this as an article please do so.

 

[JohnQuixote]

Using the evolution of weight/proportions measurements as a model it''s realistict to expect future mechanical grading for color and clarity.

For now, labs rely on Sarin to do what was originally done by hand. Sarin is not perfect, but when properly calibrated is more accurate and repeatable than human assessment. More accurate technology will replace Sarin, and will itself be replaced in the ongoing attempt to improve accuracy of proportions measurements.

From what I understand the new Imagem technology purports to measure 3 grades of color within each color grade. It does so in a completely sealed chamber with (allegedly) highly standardized equipment. If it''s more accurate and repeatable than human assessment - hard to imagine it not being so - it will be interesting to see how the industry receives it, or technologies like it.

Personally I wish Imagem would have introduced a weight-proportions/color/clarity ONLY grading machine without confusing the issue with "light performance" analysis.

More to come this week in Tucson on Imagem. Strm, some of these "future of" speculations may receive attention there.

 

[TLS]

I know some vendors use a colorimeter (might be spelling it wrong). Does anyone know how accurate that is? I had an appraiser tell me he does not feel it is accurate and only relies on his eyes and comparing against master stones.

Also didn't marty Haske invent something that measures color - I don't know much about this. Can we expect this to be used widespread anytime in the future?

 

[JohnQuixote]

The colorimeter has not proven consistent but can be used as a verifying device. The AGS uses a master stone set as well as a mechanical assessment, but the human evaluation receives priority.

Info on Marty's SAS2000 can be found here.

 

[strmrdr]

Date: 1/30/2005 1

0:20 PM
Author: JohnQuixote

Personally I wish Imagem would have introduced a weight-proportions/color/clarity ONLY grading machine without confusing the issue with ''light performance'' analysis.

Me too it might get accepted a lot quicker that way.
If it can do what its claimed to do in those areas.

 

[strmrdr]

btt

 

[strmrdr]

btt yet again :}

 

[noobie]

strmrdr

Here's my pragmatic view of the situation. Your example of buying a stone represented as a particular color and then 10 years later having it graded as a different color actually happened to me. I bought a D clor stone verifed by independent appraiser. I took it to another appraiser later who told me it was a E or borderline F. I had it re appraised recently as an E/F for insurance update. Do I care? Not really. I'm never going to sell the stone and even the guy that judged it as a E or F ten years told me I got a good deal for it even as an E or F. Interestingly enough the new appraisal listed it as higher clarity than before.

I understand that there could be a variation of a grade or so depending on who judges and under what conditions. I buy for how it looks as a piece of jewelry. Any swing in a grade of color either way ten years from now, I just consider noise given the enjoyment for the time. Besides, potential change in value due to change of grade is probably within the variation of buying prices depending upon where it is purchased. I'm not buying IF D to have an IF D. Under those circumstances I would feel differently.

That being said, I do agree that a more uniform and universal standard is desirable and would take away soem variables that make it confusing for consumers (trying to normalize market pricing based on cert). However, I do believe that there are those in the industry that benefit from the confusion and like it the way it is. Maybe that should be a topic for an article.

 

[pqcollectibles]

I think a chunk of color grading is subjective, perhaps leading to the differences from appraiser to appraiser and lab to lab.

The rough isn''t simply yellow, or simply brown, or grey, or pink, etc. While yellow and brown are the probably the 2 most predominate colors, there are other colors of rough. Even if we just look at yellow and brown, trace minerals add pigment/colot that may vary from geographic location to location, or layer to layer in the earth''s crust. The current color grading system is based on the level of hue saturation in the stone. The more saturated the hue, the lower the color grade. Could one instrument, with extremely sophisticated computer software, take into account all the potential color/pigmentation variables to arrive at an accurate color grade on a consistent basis across a variety of diamond sizes??

 

[pqcollectibles]

Bump!