4 replies to this topic

[f0rbidden]

My question of the day is this..

I have found more and more information about the grading of cut lately. Seems the GIA is about to add 'cut' to their certification process...but the documents I've read have only dealt with rbc's.

Does GIA at this time only offer to grade cut on round brilliants because they are so popular (accounting for the vast majority of diamonds sold)? OR
would other shapes become more popular if the GIA would offer to cert those cuts as well?

So in other words, does the GIA inadvertantly slow the sale of other shape diamonds because of the more extensive reporting they do on RBC's?

[ben]

Does the tail wag the dog?

In this case, I think not. Round Brilliants are more popular, therefore, GIA offers (or will offer) cut grading on them.

[barry]

Are only round brilliants that conform to Towlkowsky's measurements for "Ideal" a top visually eye pleasing cut or are there other combinations of Table-Crown-Pavillion that will be visually attractive?

GIA's 15 year research project sought to extend Towlkowsky's 1919 formulations and answer this question.

Fancy shapes because of their irregular architecture refract light in a more unpredictable manner compared to rounds and therefore assessing Cut quality in these shapes is significantly more difficult to quantify.

Eventually, GIA will have a Cut Grade for shapes other than the round brilliant.

[f0rbidden]

ok, so then that leads to the next question - WHY are round brilliant diamonds the most popular cut?

I don't think any well cut diamond with good color/clarity is unattractive, but I wouldn't want to own an RBC - they're just not my taste - my diamond of choice is an emerald cut. 2nd choice would have to be asscher, but it's not a close second.

What makes RBC's so popular?

[denverappraiser]

There are several reasons. Here’s a few:

Given good cutting, RBC’s will have better light return than any other shape.
People have been putting thought into the optics of RBC’s for quite a bit longer than for other shapes. This makes it something of a traditional look and purchases of diamonds are often all about traditions.
No points makes them generally less fragile than pears, marquise, princess etc.
Round is a nice looking shape as a component for a piece of jewelry.
The brilliant cut pavilion has a nice sparkly look to it and its’ fairly forgiving of the medium to low clarity and color grades. I-1 J RBC’s can often be quite lovely (or not). Emerald cuts, for example, will show both color and clarity variations more prominently.

Neil