When the GIA report says something different...

[Mrs_Strizzle]

Hi all,

While searching for an old cut I have discovered many listings where the seller claims it to be an OEC but the GIA says "circular brilliant", or even "round brilliant" with all the dimensions. How should I take this? Is it no big deal because of the wide range of cuts,or should I be very leery of the seller? As a colored stone girl, I immediately would rule out a seller if the ad said unheated, but the GIA contradicted that. I realize that's not really apples to apples, but you get what I mean. Thanks for any insight, as the world of diamonds is very new to me.

 

[YadaYadaYada]

Per GIA standards the requirements for the circular brilliant grading are different from the requirements for an OEC:

Circular Brilliant Cut Diamonds

Circular Brilliant Cut is a new name for an antique stone. You've likely heard of the popular antique nomenclatures Old Mine and Old Euro...

blog.eragem.com

I have always understood that a circular brilliant would look more transitional than OEC.

 

[oldminer]

There are exact sets of cut parameters that GIA has synthesized, in a rather arbitrary way, which limit their use of OEC as a description. They use the alternatives you mentioned when a diamond is outside their GIA parameters for OEC. However, GIA does not dictate to the trade or to the world of dealers what makes a diamond look or be an OEC. When a dealer disagrees, there is no entity in charge and they are free to use the terminology they feel best describes the diamond they are selling.
This is not remotely related to an example of not revealing a gemstone has been enhanced or treated.

 

[Rockdiamond]

Interesting question!
I always like to include the GIA nomenclature on OEC, OMB and circular brilliants due to this exact confusion.
OTOH.... the words “Radiant Cut” and “Princess Cut” don’t appear on GIA reports and we use those all the time......

ETA- IMO, this is not in the same category as false claims about heating.....

 

[Mrs_Strizzle]

There are exact sets of cut parameters that GIA has synthesized, in a rather arbitrary way, which limit their use of OEC as a description. They use the alternatives you mentioned when a diamond is outside their GIA parameters for OEC. However, GIA does not dictate to the trade or to the world of dealers what makes a diamond look or be an OEC. When a dealer disagrees, there is no entity in charge and they are free to use the terminology they feel best describes the diamond they are selling.
This is not remotely related to an example of not revealing a gemstone has been enhanced or treated.

Thank you for this info. I was leaning towards this since I see it so often, but wanted it clarified by someone more knowledgeable- than me.

 

[denverappraiser]

For a diamond to be graded an Old European Cut by GIA, it must:

Table size must be less than or equal to 53%.

Crown angle must be greater than or equal to 40 degrees.

The lower half facet length must be less than or equal to 60%.

The culet size must be 'slightly large' or larger.

Obviously there are lots of older stones that fail on one or more of these and comparing them unfavorably to a Modern Round Brilliant is clearly unreasonable. Enter the Circular Brilliant.