Pre-Auction Analysis: April 29, 2022, Sotheby’s Hong Kong Magnificent Jewels

As most of the industry has been unable to travel during this challenging period, this Auction Analysis could help those who would like to bid without physically inspecting the goods.                                                 

Our Sotheby’s Hong Kong Pre-Auction Analysis focuses on elements that aren’t visible to the untrained eye. We will describe the important visual elements for those who cannot attend the preview and discuss characteristics such as: Undertone, Color Dispersion, and Inner-Grade. These factors, collectively termed UDI, are explained in detail at the end of this article. We analyze and grade Fancy Color Diamonds 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 UDI score of 8, 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 jewelry brands, collectors, and the investment community.

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

• All images in this article review were taken with an iPhone 12 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 to verify 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: 1891
Description: 5.11 ct, Fancy Vivid Purplish-Pink, Radiant, VS2
High Auction Estimation: $2,494,872 pc
Didn’t reach the minimum
Rarity: A similar diamond enters the market once every… Check Rarity Here.
GIA Report: View

Analysis:
Pink Fancy Color diamonds with a vivid grade are becoming significantly rarer with time, especially above the one-carat weight. According to FCRF rarity data, a diamond with these exact parameters of shape, weight, clarity, and color grade enters the market just once a decade.
The purple modifier adds a cooler, pleasant hue sensation to the overall appearance, while the inner-grade is above average. Several colorless patches can be seen on the crown, and the stone’s dimensions correspond to its weight, resulting in high overall visual assets.
As you view our images of this stone, we wish to draw your attention to the rounded outline of the gold cup underneath the stone that may affect one’s impression of the rectangular shape of this traditional radiant cut.

Visual Assets:

Total Visual Score: 10 out of 12

Lot: 1880
Description: 17.03 ct, Fancy Vivid Yellow, Radiant, VS2
High Auction Estimation: $52,402 pc
Price Realized: $58,450 pc
Rarity: An extremely small number of similar diamonds enter the market yearly…Check Rarity Here.
GIA Report: View

Analysis:
A large Vivid Yellow radiant-cut diamond with large, colorless patches on the crown. The facet alignment makes it clear that this stone was repolished from what was once a round brilliant to reinforce its color, a procedure that often just results in a “Good” symmetry. The face-up dimensions of the stone correspond to a larger weight and no significant green or brown undertone is visible.

Visual Assets:

Total Visual Score: 8 out of 12

Lot: 1865
Description: 5.17 ct, Fancy Purplish-Pink, Pear, VS2
High Auction Estimation: $221,933 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 fancy purplish-pink pear shape with a pleasant undertone, low inner-grade, and noticeable colorless areas on the crown. The fluorescent grade on the GIA report is “Strong Blue”.

Visual Assets:

Total Visual Score: 7 out of 12

Lot: 1863
Description: A parcel of 7 unmounted Fancy Color Diamonds.
High Auction Estimation: $56,915 pc – each diamond is analyzed separately.
Price Realized: $33,587 pc

Sub Lot: 1863 (1)
Description: 0.76 ct, Fancy Intense Green-Yellow, Radiant, SI2
GIA Report: View

Analysis:
An intense green-yellow diamond with a high depth percentage of 79% resulting in a smaller face-up view relative to its carat weight. The diamond’s blue fluorescent grade is very strong, and its clarity is SI2.

Visual Assets:

Total Visual Score: 10 out of 12

Sub Lot: 1863 (2)
Description: 0.74 ct, Fancy Deep Yellow-Orange, Radiant, I1
GIA Report: View

Analysis:
A fancy deep orange color with a 40% yellow color as a modifier. The stone is highly saturated and its color dispersion is not high. Clarity is I1 and the GIA report is dated 2011.

Visual Assets:

Total Visual Score: 9 out of 12

Sub Lot: 1863 (3)
Description: 0.68 ct, Fancy Green, Oval, SI2
GIA Report: View

Analysis:
A fancy green oval with high visual assets and SI2 clarity. The GIA report is dated 2017.

Visual Assets:

Total Visual Score: 10 out of 12

Sub Lot: 1863 (4)
Description: 0.63 ct, Fancy Brownish-Orangy-Pink, Oval, VVS1
GIA Report: View

Analysis:
A diamond with a pink body color and significant brown and orange color modifiers that create a warm appearance.

Visual Assets:

Total Visual Score: 10 out of 12

Sub Lot: 1863 (5)
Description: 0.61 ct, Fancy Vivid Yellow, Pear, VS1
GIA Report: View

Analysis:
A Vivid Yellow pear shape with strong inner-grade and high color dispersion. The GIA report is dated 2018.

Visual Assets:

Total Visual Score: 10 out of 12

Sub Lot: 1863 (6)
Description: 0.55 ct, Fancy Vivid Yellowish-Orange, Pear, VS2
GIA Report: View

Analysis:
A Vivid Yellowish-Orange diamond with high visual assets supported by a yellow fluorescent.

Visual Assets:

Total Visual Score: 12 out of 12

Sub Lot: 1863 (7)
Description: 0.51 ct, Fancy Greyish-Yellowish green, “Chameleon” Pear, VS2
GIA Report: View

Analysis:
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Visual Assets:

Total Visual Score: 12 out of 12

Lot: 1841
Description: 3.27 ct, Fancy Vivid Blue, Cushion, IF
High Auction Estimation: $1,754,422 pc
Price Realized: $1,617,676 pc
Rarity: A similar diamond enters the market once every…Check Rarity Here.
GIA Report: View

Analysis:
A Fancy Vivid Blue cushion, cut and polished as an old mine diamond with a typical open culet. Its color dispersion is low, which is an accepted visual characteristic in stones polished in this manner. A noticeable gray undertone is visible in the diamond’s hue, reinforcing its overall inner-grade. The face-up dimensions are large relative to its weight.  

Visual Assets:

Total Visual Score: 8 out of 12

Lot: 1821 – Color report only
Description: 1.06 ct, Fancy Red, Radiant
High Auction Estimation: $312,706 pc
Price Realized: $530,190 pc
GIA Report: View

Analysis:

A 1.06 Fancy Red cushion cut diamond with a color-only GIA report. When placing the stone under a UV diamond lamp, its fluorescence seemed significant, as seen in the picture above. A large black crystal is placed under the table, which may correspond to an I1 clarity or lower.
Strong Inner-grade is an inherent characteristic of Fancy Red diamonds, and as such, it receives the highest possible inner-grade. The color is dispersed nicely around the stone’s face-up view, and its undertone is quite warm.

Visual Assets:

Total Visual Score: 10 out of 12

Lot: 1806
Description: 4.00 ct, Fancy Yellow, Pear, VS2 and 4.00 ct, Fancy Yellow, Pear, VS2
High Auction Estimation: $19,115
Price Realized: $$15,053 pc
Rarity: An extremely small number of diamonds, similar to each diamond in this pair, enter the market yearly… Check Rarity Here.
GIA Reports: View and View

Analysis:
A matching pair of Fancy Yellow pear-shaped diamonds with excellent visual parameters. The dimensions of each diamond are similar, though their table size and outlines differ. Their identical 4.00 carat weight, which could be perceived as less attractive in a single stone, adds a sense of compatibility to the pair, as both have the same exact unusual weight.

Visual Assets:

Total Visual Score (each): 12 out of 12

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.