Color grades and size

[kenny]

Imagine two round brilliant flawless diamonds with the exact same proportions.
Let's say AGS gave them both the color grade J.

One is 4 mm in diameter, the other is 8 mm.

Place them both, side by side, table down in laboratory conditions under the proper lighting for color grading diamonds.

Will the color look the same?
Or will the 8 mm look more yellow since your are looking through twice as much colored material as in the 4 mm.

 

[Dee*Jay]

I would *imagine* that the color would become apparent at some grade, but not at the higher levels. I.e., Ds would look the same, Es would look the same, etc., maybe down to Is or Js where color seems to show more in larger stones (?). This is purely speculation on my part but it seems reasonable...

 

[kenny]

bump

 

[Lorelei]

I would say the 8mm would look more tinted as generally the larger you go the more colour can be seen.

 

[oldminer]

You will not find any other transparent material color grade as diamonds are graded. Even D color looks darker in large stones than in smaller stones. To my eyes and in my lighting, a 5 carat GIA D looks more E/F borderline when using carat sized master stones. The increase in apparent body color as size increases is even more pronounced on stones with some tint of coloration.

A colorless glass topped coffee table is green when viewed from the side edge. It still is colorless glass, but the absorption of light through its width is far great than the absorption of light through its much more shallow depth. When one wants a glass photographic filter, it is determined simply by the amount of color visible in its depth. One must keep in mind that filters are not sold for thousands of dollars by the carat.

When it comes to diamonds, a unique material of high value, the cutters, dealers and the labs have long preferred to use a color grade related to the inherent body color of the rough and smallish master diamonds, and to a great extent they disregard the finished size of the diamond and how it compares to smaller masters. This is how the market works and this is a given that consumers can understand. It is a totally logical strategy, though unique, and the market is free to respond if dealers disagree. It is because of the huge dollar values that we have this quite subjective system which seems to have succeeded in operating for many years.

Of course, Fancy Color diamonds are graded "face-up". Why? Well, the cutter uses skill to create the right blend of face-up color or to intensify color in the face-up view by carefully engineering facets to do the job. Again, it is a free market function that has worked well for many years. It does seem illogical on first glance to grade some diamonds one way and other diamonds another, but when one looks at market forces, the end result fits the current market model.

 

[Cehrabehra]

Date: 9/8/2006 1:06:30 PM
Author: oldminer
You will not find any other transparent material color grade as diamonds are graded. Even D color looks darker in large stones than in smaller stones. To my eyes and in my lighting, a 5 carat GIA D looks more E/F borderline when using carat sized master stones. The increase in apparent body color as size increases is even more pronounced on stones with some tint of coloration.

ahhh like water... even enough to fill a bathtub can sometimes take on a tint....

 

[kenny]

Thank you.
So I guess that settles it.

The larger the diamond the more color it will have for a given color grade.

So it stands to reason that if you are buying a smaller stone you can get away with a less expensive color grade.

If you are buying a larger stone it is even more important to spend the money for an even more expensive color grade.

In other words a small I J or K shows less color than a larger I J or K.

 

[Rhino]

Excellent input Dave and yes Ken. You''re right on with your last comment. In many instances when folks are using say an H colored center stone it is possible for them to use I-J color side stones with no worry in contrast between the appearances so long as the cuts on them are similar.