New Industry Standard

We identify three primary visual characteristics of fancy color diamonds: 

Inner-Grade, Color Dispersion, and Undertone (IDU).

We use grades 1, 2, 3, and 4. Grade 1 being the lowest quality grade and Grade 4+ is the highest possible grade, granted in rare cases and denotes stones with exceptional quality characteristics.

Inner-Grade refers to the strength of color within each GIA saturation category:

Grade 1, weakest, bordering the saturation below.

Grade 2, weak (most common).

Grade 3, full-bodied color.

Grade 4, very strong saturation.

Undertone refers to a subtle hue influence in the body color of the stone.

For example: In a pink fancy color diamond, a stone with a warm undertone (leaning towards orange or brown) will receive a low grade. A pink stone with a cold purple undertone will receive a high grade.

Color Dispersion refers to how color is dispersed in a fancy color diamond’s face-up view.

This is regardless of whether the GIA grades the stone as “even” or not. A stone with many colorless areas will receive a low grade, while a stone that exhibits its face-up view with absolutely no colorless patches, will receive a grade of 4+. 

The FCRF’s characteristics have become the industry standard for leading jewelry brands. They allow for an accurate description of a diamond’s visual assets among professionals, retailers, and private clients. In auction analyses, these descriptions are essential, as auction catalog images often disguise stones’ visual flaws.

Here are a few examples of our visual analyses from our previously published Pre-Auction Analysis articles that show how our methodology is implemented.

__________________________________________________________________________

12.98 carat Fancy Deep Orange Yellow Pear Shape, VS2

Unprocessed FCRF images                   
 

Auction Catalog  image

Visual Assets:
Inner Grade..………………4
Color Dispersion.………3
Undertone..…………………2
Total Visual Score…….9 out of 12

FCRF Analysis: Interestingly, this orange-looking pear-shaped diamond has two states of appearance. The first has an unattractive dark undertone (with some brown flashes) under standard indoor lighting. The other appearance looks completely different, with a strong, orange hue when viewed in direct sunlight. This phenomenon is due to the glowing effect of the diamond’s yellow fluorescence when it meets UV rays from the sun. The two images shown clearly demonstrate this phenomenon.  

*This diamond was offered at Christie’s Geneva, on May 16th, 2018.

__________________________________________________________________________

33.51 carat Fancy Light Purplish Pink Rectangular-Cut Cornered, VS2

Unprocessed FCRF images
 

Auction Catalog image

Visual Assets:
Inner Grade..………………1
Color Dispersion.………2
Undertone..…………………3
Total Visual Score…….6 out of 12

FCRF Analysis: Some areas of this large, pink diamond are milky, and they are visible when viewed through its girdle. The Inner-Grade is low, and the diamond loses most of its body color in direct sunlight (typical for type IIa pink diamonds). The color appears mainly under the table, leaving the crown completely colorless. On one side of the girdle, there is a large, natural indent that may be visible to the naked eye (image attached). As with most lots, there is no resemblance between the stone’s appearance in real life and its catalog image.

*This diamond was offered at Christie’s Geneva, on May 16th, 2018.

__________________________________________________________________________

3.44 carat Fancy Vivid Purplish Pink, Radiant Cut, IF.  MOUSSAIEFF. 

Unprocessed FCRF image           
 

Auction Catalog image

Visual Assets:
Inner Grade..………………4
Color Dispersion.………4
Undertone..…………………4
Quality Remark…..Strong blue fluorescence
Total Visual Score………12

FCRF Analysis: A Vivid Purplish-Pink diamond with exceptional visual characteristics that meets our expectations of a pink diamond. The undertone has the right amount of purple in the mix, the color is dispersed all around the face-up view, and the strength of color is at its maximum level. The ‘Strong Blue’ fluorescence doesn’t have a negative visual effect on this pink diamond. However, some buyers give great importance to gemological features that generate a discount in colorless diamonds, even if they have no negative visual effect on fancy color diamonds.

*This diamond was offered at Christie’s Hong Kong, on May 28th, 2019.

__________________________________________________________________________

A pair of 6.49 and 6.10 carat diamonds, Fancy Intense Yellow, Round, IF

Unprocessed FCRF image                                    

Auction Catalog image

Visual Assets:
Inner Grade..………………3
Color Dispersion.………2
Undertone..…………………3
Quality Remark…..Deformed Face Up
Total Visual Score……..8

FCRF Analysis: These are two Round Brilliant-cut diamonds with similar dimensions, Inner-Grade, and Undertone. However, the stones have different table sizes (67% and 63%), leading to low compatibility as a matching pair. The steep angles on the diamonds’ crown and pavilion make it evident that they underwent major recutting to concentrate color under the table and a dark colorless crown at the same time. This visual contrast usually leads to an “Intense” grade at the expense of creating a deformed face up with low color dispersion.

*This diamond was offered at Sotheby’s Hong Kong, on July 19th, 2022.

__________________________________________________________________________