AGS Certificate Question

[jennyann2]

I was looking at the following diamond and noticed on the AGS Certificate that there was a little note stating "Clouds are not shown." What exactly does that mean? Is this stone going to be cloudy/hazy?

Thanks for the help, I''ve learned so much from reading this forum....I think I have a long way to go though!

Shape: A Cut Above H&A
Carat: 1.222
Color: I
Clarity: SI1
Depth: 60.6
Table: 55
Crown Angle: 34.8
Crown %: 15.6
Pavilion Angle: 40.8
Pavilion %: 43
Girdle: 0.9%-1.4%FACETED
Polish: Ideal
Symmetry: Ideal
Culet: Pointed
Fluorescence: Negligible
Measurements: 6.96-6.98X4.22

 

[Garry H (Cut Nut)]

It means they never ever attempt to draw a cloud on a report- they only ever write it as a comment. It is OK

 

[oldminer]

Sometimes a cloud is represented by a series of dashes, surrounding the outline of the "cloud", but more often than not, a cloud is a comment and not drawn into the plot. The dashed line image looms rather large and overly important compared to the effect most clouds actually have. Most clouds have very little visual impact. Also, a cloud or clouds may be extensive or difficult to find their borders. You would find it unpleasant to see an entire diamond circled by a dashed line indicating nearly the entire stone was clouded unless there was some real visual impact. WHo'd buy such a diamond if they had another choice? So that's why.

What will the presence of a cloud or clouds do to the predictive ray tracing AGS hopes to employ next year in light behavior grading? Will that have any impact on the accuracy of these results?

 

[Garry H (Cut Nut)]

Interesting point Dave - GIA found in their recent study for their Foundation for Grading that clouds that were the clarity grade determining factor (i.e. there were no other inclusions - only the cloud(s)) that grades with SI2 and lower - the cloud(s) reduced the fire.

They also found that fair or poor polish reduced brightness and fire and that as color became more saturated on the D-Z scale that brightness decreased.

 

[oldminer]

A body color increases from colorless to tinted, regardless of the hue, the color, there is less brightness possible as more and more light is absorbed from the increasing deep body color.l Now, this effect is rather nominal in the upper color grades where body color is very slight anyway, but overall brilliancy will definitely decrease as color intensifies. Brightness also decreases as size increases. The thicker the stone, the more light is absorbed within. Larger diamonds cannot be as bright as smaller diamonds.

These issues pose huge problems for simplistic approaches to brilliancy grading. Unless a whole lot of extremely detailed factors are programmed into the ray/beam tracing situation, the resultant answers will be bogus.