Pre-Auction Analysis: June 16, 2022, Sotheby’s New York – Magnificent Jewels

Our Sotheby’s New York Pre-Auction Analysis focuses on elements that aren’t visible to the untrained eye. We describe important visual elements for those who cannot attend the preview. We discuss characteristics such as: Inner-Grade, Color Dispersion, and Undertone – collectively termed IDU. These visual assets are explained in detail at the bottom of this article.

It is important to note that we analyze and grade these Fancy Color Diamonds under LED light and relative to their GIA grade.

We use grades 1, 2, 3, and 4, with 1 being the lowest grade. Grade “4+” is granted in rare cases and denotes stones with exceptional characteristics. Stones that receive a minimum total IDU score of 9, without a red remark, pass the industry threshold and can be traded easily. Fancy Color Diamonds that are graded 10 or above (without a quality remark) are usually sought after by high-end jewelers and collectors.

For your convenience, we have added direct links to the GIA reports.

• All images in this article review were taken with an iPhone 13 Pro; no filters were applied.
• All auction valuations are per-carat and listed in US Dollars.

Disclaimer
This analysis reflects the opinions of the FCRF professional team. It does not constitute a recommendation to buy or not buy a particular diamond. Buyers assume the responsibility of verifying any information with the auction house. At times, mistakes can happen in the visual analysis and report placement. Therefore, one should not rely solely on this analysis for buying purposes.

Lot: 445
Description: 3.02 ct, Fancy Vivid Yellow, Emerald-Cut, VVS2
High Auction Estimation: $300,000 total
Didn’t reach the minimum
Rarity: A similar diamond enters the market once every… Check Rarity Here.
GIA Report: View

Analysis:
A Square Vivid Yellow Emerald-cut diamond, cut and polished with a classic colorless facet alignment resulting in low color dispersion. The Inner-Grade is solid, and no green or brown undertone is present in the hue.

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

Lot: 448
Description: 19.83 ct, Fancy Intense Yellow, Oval, VVS2
High Auction Estimation: $27,735 pc
Price Realized: $30,500 pc
Rarity: An extremely small number of similar diamonds enter the market yearly… Check Rarity Here.
GIA Report: View

Analysis:
A large Fancy Intense Yellow Oval-cut diamond with a solid Inner-Grade. The color concentration was not done meticulously, resulting in large, colorless areas in the center of the table from the face up.

Visual Assets:
Inner Grade..……………….3
Color Dispersion.………2
Undertone..…………………3
Total Visual Score…..8 out of 12
Quality Remark…………Low Color Dispersion

Lot: 454
Description: 1.02 ct, Fancy Vivid Blue-Green, Radiant, I1 and  1.01 ct, Fancy Vivid Orangey-Yellow, Radiant, I1
High Auction Estimation: $350,000 total
Price Realized: $252,000 total
Rarity: A diamond, similar to this Orangey-Yellow one, enters the market once every… Check Rarity Here.
GIA Reports: View and View

Analysis:
The 1.02 Fancy Vivid Blue-Green Radiant-cut diamond has a solid Inner-Grade and almost no colorless patches on the face-up view of the stone. The overall color sensation of the stone, however, does not fully correspond to its GIA color description, as it appears less blue than expected. The I1 clarity is a result of black crystals scattered in the stone and reflected among the pavilion facets.

The 1.01 Fancy Vivid Orangey-Yellow radiant has a solid Inner-Grade and a very pleasant undertone. The I1 clarity results from some large feathers.
According to the laser inscription on both diamonds, it appears that they were once part of a small, private collection called Olympia.

Visual Assets:
1.02 ct
Inner Grade..……………….3
Color Dispersion.………4
Undertone..…………………2
Total Visual Score…..9 out of 12
Quality Remark…………I1 Clarity

1.01 ct
Inner Grade..……………….3
Color Dispersion……….3
Undertone..…………………4
Total Visual Score…..10 out of 12
Quality Remark…………I1 Clarity

Lot: 456
Description: 0.40 ct, Fancy Red, Radiant, SI1 and 0.39 ct, Fancy Red, Radiant, VS2 and 0.31 ct, Fancy Red, Radiant, VS1
High Auction Estimation: $772,727 pc
Didn’t reach the minimum
GIA Reports: View, View and View

Analysis:
A brooch with three Fancy Red Radiant-cut diamonds, with relatively high clarity grades for their color category. Inner-Grade does not apply here, as red diamonds come only in the “Fancy” category due to the fact that red is a highly saturated color in diamonds. Color dispersion is high in all three stones. Of all  three, the 0.39 appears less red than expected compared with the other two.

All GIA reports are dated 2010

Visual Assets:
0.40 ct
Inner Grade..………………N/A
Color Dispersion.………4
Undertone..…………………3
Quality Remark…………None

0.39 ct
Inner Grade..………………N/A
Color Dispersion……….3
Undertone..…………………3
Quality Remark…………None

0.31 ct
Inner Grade..………………N/A
Color Dispersion.………3
Undertone..…………………3
Quality Remark…………None

Lot: 457
Description: 3.69 ct, Fancy Blue, Radiant, VS2
High Auction Estimation: $203,252 pc
Didn’t reach the minimum
Rarity: An extremely small number of similar diamonds enter the market yearly… Check Rarity Here.
GIA Report: View

Analysis:
An elongated Fancy Blue, Mixed-Cut, Radiant. The crown is decorated with steps, while the pavilion is polished with a Starburst facet alignment. Because Fancy Color Diamonds are polished “freestyle”, and a mixed-cut style is very common among square and rectangular shapes, it doesn’t impact the appearance of the stone. The Inner-Grade is below the average color for Fancy Blue diamonds, and no significant gray undertone is seen in the hue. The stone appears a bit large relative to its carat weight.

Visual Assets:
Inner Grade..……………….2
Color Dispersion.………3
Undertone..…………………3
Total Visual Score…..8 out of 12
Quality Remark…………Low Inner-Grade

Lot: 458
Description: 15.23 ct, Fancy Vivid Yellow, Pear, IF
High Auction Estimation: $52,528 pc
Price Realized: $43,020 pc
Rarity: An extremely small number of similar diamonds enter the market yearly… Check Rarity Here.
GIA Report: View

Analysis:
A large Fancy Vivid Yellow Mixed-Cut Pear shape. The stone has a traditional Starburst facet alignment on the bottom, and steps on the very steep crown. Fancy Color Diamonds are polished in a freestyle manner, and nearly any appearance is acceptable in the trade. However, diamonds with a rounded contour that incorporate geometric facets along their outline may be unusual in traditional jewelry designs.

The Inner-Grade is very low, bordering on the intense grade, and no green or brown undertone is seen in the hue.

Visual Assets:
Inner Grade..……………….1
Color Dispersion.………3
Undertone..…………………4
Total Visual Score…..8 out of 12
Quality Remark…………Low Inner-Grade

Lot: 459
Description: 3.46 ct, Fancy Gray-Violet, Old-Mine-Cut, SI1
High Auction Estimation: $202,312 pc
Price Realized: $573,988 pc
GIA Report: View

Analysis:
A Fancy Gray-Violet Old Mine Diamond. According to the GIA, it has a ~40% Gray modifier and ~60% Violet as its body color. Diamonds with a violet body color are very rare in nature, particularly in sizes above 1 carat. This diamond was probably manufactured at the beginning of the previous century, and its SI1 clarity results from chips and bruises surrounding the stone, most of which could likely be polished out. The gray hue reinforces the Inner-Grade, and color dispersion is low, although typical of this type of antique cut. Industry professionals wishing to reintroduce this stone into the jewelry market will likely repolish the diamond and improve its appearance.

Visual Assets:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score…..9 out of 12
Quality Remark…………None

Lot: 460
Description: 4.08 ct, Fancy Intense Pink, Old-Mine-Cut, VS2
High Auction Estimation: $441,176 pc
Price Realized: $931,617 pc
GIA Report: View

Analysis:
A Fancy Intense Pink Old Mine Cushion-shaped diamond. Looking at the facet alignment and the external marks on the stone, we can assume the stone was manufactured at the beginning of the last century. A warm undertone is notable in the pink hue, and as expected, color dispersion is low and appears asymmetrically across the face-up of the diamond. Industry professionals wishing to reintroduce this stone into the jewelry market will likely repolish the diamond and improve its appearance.

Visual Assets:
Inner Grade..……………….3
Color Dispersion.………2
Undertone..…………………2
Total Visual Score…..7 out of 12
Quality Remark…………Warm Undertone

Lot: 499
Description: 41.02 ct, Fancy Intense Yellow, Radiant, VS2
High Auction Estimation: $29,254 pc
Didn’t reach the minimum
Rarity: An extremely small number of similar diamonds enter the market yearly… Check Rarity Here.
GIA Report: View

Analysis:
A very large Fancy Intense Yellow Radiant cut with a low color Inner-Grade and very few colorless patches on the face-up view.

Visual Assets:
Inner Grade..……………….2
Color Dispersion.………4
Undertone..…………………3
Total Visual Score…..9 out of 12
Quality Remark…………None

Lot: 510
Description: 5.89 ct, Fancy Brownish-Orangey-Pink, Radiant, VS2
High Auction Estimation: $76,400 pc
Didn’t reach the minimum
GIA Report: View

Analysis:
An elongated Fancy Brownish Orangey-Pink Radiant cut, with pink being the prominent color. The stone is surrounded by pink gold, which affects its overall appearance and means that the three visual assets should be regarded with reservation.

Visual Assets:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score…..9 out of 12
Quality Remark…………None

General

We use 1, 2, 3, 4, and 4+ to grade the three visual elements that GIA is silent about, although they impact the value dramatically.

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 (above average).
Grade 4 very strong saturation.
Grade 4+ applies to the vivid category only, exhibiting the strongest possible saturation (rarely seen).

Undertone refers to a subtle hue influence in the body color of the stone.
For example:
A Fancy Blue Diamond with a significant gray presence in its general appearance will be graded with a low undertone grade of 1. A Fancy Blue that has no gray influence that is close to a primary blue will receive the grade, 4.
In a Pink Fancy Color Diamond, a stone with a warm undertone (such as orange or brown) will receive a low undertone grade. A pink stone with a cold undertone (such as purple) will receive a high grade.
In Yellow Fancy Color Diamonds, low foreign influence or a light orange influence will grant the stone a high undertone grade. When the yellow undertone looks like a true primary yellow, it will receive the rare grade 4+. Green and brown undertones will grant a low grade in the yellow category.

Color Dispersion relates to how well the color is dispersed in the face-up view of a Fancy Color Diamond, regardless as to whether the GIA grades the stone as even. A stone with many colorless areas will receive a grade of 1, while a stone that exhibits its face-up view with no colorless patches will receive a grade of 4+. Unlike the first two elements, the color dispersion is not a gemological quality and is the result of cutter proficiency.