are clarity grading parameters changing?

[bgray]

I have an EC vs2 stone with some crystals and a needle. and "pinpoints are not shown." I think its an exceptionally clean vs2. I have been looking for a new stone for myself and the vs2''s seem just full of feathers, clouds, indented naturals etc....has anyone noticed this?

 

[jadedpony]

GIA? I just bought a VS2 and the only inclusions listed were crystals. Seemed like as soon as I looked at SI1''s, feathers and clouds were present and being listed.

 

[bgray]

yes GIA. i only look at vs2 or 1...just seems like lots of "stuff" in the stones i have been reviewing

 

[elle_chris]

I have a GIA VS2 with clouds so I don''t think the type of inclusion is what''s making the grade. I do think it has more to do with size and location.

Rgith now I''m looking at a GIA VS1 with a feather and cloud listed on the cert. When I look at the stone magnified, I don''t see the feather or cloud but I do see a crystal. In fact, it''s pretty obvious and yet wasn''t the grade setter. So who really knows..

 

[jadedpony]

My stone was certified in 2007. When were the ones that you''re looking at certified? The most noticable flaw was a very small black carbon inclusion visible through the table, near the pavilion :shrug:

 

[Todd Gray]

Date: 10/8/2009 9:25:38 AM
Author:bgray
I have an EC vs2 stone with some crystals and a needle. and ''pinpoints are not shown.'' I think its an exceptionally clean vs2. I have been looking for a new stone for myself and the vs2''s seem just full of feathers, clouds, indented naturals etc....has anyone noticed this?

Diamond clarity grades are based on the type of inclusion, but also on the size and/or extent of the inclusion as well as the number of inclusions and location within the diamond. So one VS-2 clarity diamond might contain a single small diamond crystal within the table facet and another might contain several inclusions scattered about along the perimeter of the diamond and so on... It literally is a case by case scenario and is largely dependent upon the opinion of the person grading the diamond.

However there is also a tendency for the labs to adjust their grading parameters and it is my opinion that the VS-2 of today is more like the SI-1 of a decade ago, the SI-1 of today is more like the SI-2 of ten years ago and so on... Perhaps this is due to pressure from within the industry? While most of the gemological laboratories are operated on a non-profit for education type of platform, I don''t think that anything is ever really ''non-profit'' and thus when a diamond cutter with an annual volume of say, $80M tells ''Lab X'' something like "you know, if I''d sent this diamond to ''Lab Y'' I would have gotten a higher color or higher clarity grade, such as..." then perhaps the labs alter their grading standards to keep that cutter''s business? Okay, that''s my contribution to the consipiracy theory

Realize that the two dimensional representation of the inclusions within a diamond is not an accurate representation of the extent of the inclusions beyond indicating where the inclusions appear within the diamond from a top down vantage point. In reality, the inclusions can be located anywhere within the depth of the section represented and thus they may or may not be easily located from that particular vantage point. There are many times during a diamond evaluation where I am trying to locate something like a needle shaped diamond crystal indicated to be in the center of the table facet where the inclusion is not easily found by looking through the table facet at a direct ninety degrees through the microscope and the inclusion is eventually found by tilting the diamond this way, that way, rotating it, rocking it back and forth and looking for a glimpse of something that catches the light until the inclusion is identified. I feel that this is one reason it is important for consumers to work with vendors who actually see the diamonds that they sell and provide detailed representations of the diamond so that they can get a good idea of what the inclusions within the diamond really look like and where they are located, beyond the basic representation provided on the plotting diagram.

 

[30yearsofdiamonds]

GIA grades about 20,000 diamonds per week, between NY, CB and India. They have approx. 400 diamond graders. Lets pretend for a minute that they graded 20, 000 VS2''s last week and were acucurate on 90% of them. That will leave 2000 VS2''s either graded too high or too low, and that is alot. It''s the nature of the grading business and the inability of a % of diamond graders to grade consitently correct.

 

[oldminer]

AFTER THE 90% FIGURE FOR "CORRECTLY GRADED IS USED, THEN 2000 DIAMONDS ARE GRADED HIGH OR LOW. Dealers frequently toss out reports for those diamonds which are graded lower than expected and send them to another lab for grading hoping to get luckier on the next go-round.

Therefore, the market is left with 100 overgraded diamonds which made the dealers extra happy. This throws a real curve into trying to figure out why labs appear to be softer on grading when they may be doing a somewhat different job then what reports are left in circulation in the open market. There are many forces at work.

 

[bgray]

WOW-thanks for the perspective!

 

[Rockdiamond]

Great points raised guys! No question human error comes into play.

There are a lot of borderline stones that can go either way.
One day it looks like a VS2, the next looks like an SI1.
This can happen even if it''s looked at twice by the same grader.
I know it''s happened to me more times than I can remember.