Pre-Auction Analysis: Christie’s New York, June 11th, 2024

Pre-Auction Analysis: Christie’s New York, June 11th, 2024, 

Our Christie’s Magnificent Jewels Pre-Auction Analysis focuses on elements that are not always visible to the untrained eye. We discuss characteristics such as Inner-Grade, Color Dispersion, and Undertone – collectively termed IDU. Professionals use the IDU method intuitively when analyzing a Fancy Color Diamond. The acronym we use makes these elements easier to remember. 

Members who read this analysis should see it as a valuable supplement to the GIA report. A detailed explanation of the FCRF’s grading methodology can be found at the end of this article. We recommend reviewing it closely to broaden one’s professional vocabulary for describing fancy color diamonds to clients.  

Please note that we analyze and grade diamonds under LED lights and relative to their grade on the GIA report.

The Grades

We use grades 1, 2, 3, and 4, with 1 being the lowest grade. Grade “4+” is granted in rare cases and denotes diamonds with exceptional characteristics. diamonds that receive a minimum total IDU score of 9 without a red remark pass the industry premium 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 diamonds’ GIA reports and FCRF rarity stats.

• All images in this analysis were taken with an iPhone 13 Pro; no filters were applied.
• All auction valuations are per-carat and listed in US Dollars.
• The FCRF evaluates chosen diamonds during each auction based on expert judgments.

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.

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Lot 32

Description: 5.43 ct, Fancy Intense Orangy Pink, Marquise, I1
High Auction Estimation: $92,082 pc
Price Realised: Didn’t reach the minimum
GIA

Analysis: A large Pink marquise with an orange modifier. The I2 clarity grade is due to a large number of transparent crystals scattered under the table. The warm Undertone is quite prominent.

Quality Remark: I2

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Lot 55

Description: 6.09 ct, Fancy Vivid Yellow, Emerald, VVS1
High Auction Estimation: $57,472 pc
Price Realised: $130,345 pc
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 7.14 ct = 17.2% larger

Analysis: A Fancy Vivid Yellow, rectangular emerald-cut diamond with a high Inner-Grade and typical Color Dispersion characteristic of emerald-cut diamonds with a classic, non-modified cut. No significant green or brown Undertones are visible in the hue.

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Lot 58

Description: 3.18 ct, Fancy Vivid Pink, Cushion, IF
High Auction Estimation: $1,572,328 pc
Price Realised: Didn’t reach the minimum
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 3.57 ct = 12.3% larger

Analysis: Analyzing the facet alignment of this odd-shaped Vivid Pink, it is reasonable to assume it was recut from an older polished diamond that didn’t fulfill its color potential. Significant large colorless patches in the culet and crown detract from the overall aesthetic. The cooler purple Undertone is pleasant, although the Inner-Grade is very low, bordering on the Intense grade.  

Quality Remark: Low Inner-Grade and Dispersion

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Lot 86

Description: 9.55 ct, Fancy Orangy Pink, Oval, VVS1
High Auction Estimation: $125,655 pc
Price Realised: $85,760 pc
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 10.85 ct = 13.6% larger

Analysis: A large Fancy Orangy Pink oval with a low Inner-Grade and noticeable colorless area in the center of the shape.

Quality Remark: Low Inner-Grade

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Lot 115

Description: 84.05 ct, Fancy Intense Yellow, Cushion, IF
High Auction Estimation: $23,796 pc
Price realized: $25,789 pc
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 84.7 ct = 0.8% larger

Analysis: A very large Fancy Intense Yellow cushion cut diamond with prominent colorless patches on the crown. The Inner-Grade borders on the Vivid saturation while exhibiting an absolute yellow hue.

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Lot 136

Description: 2.28 ct, Fancy Vivid Blue, Heart, VVS1 potentially IF
High Auction Estimation: $1,140,351 pc
Price realized: $924,123 pc
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 3.08 ct = 34.9% larger

Analysis: A 2.28 ct Fancy Vivid Blue heart-shaped diamond with a significantly large face-up, giving it the visual appearance of a 3-carat diamond. The Inner-Grade is weak, yet it displays an absolute blue color without any gray Undertones.

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Lot 137

Description: 33.65 ct, Fancy Intense Yellow, Radiant, VS2
High Auction Estimation: $19,317 pc
Price realized:$19,097 pc
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 38.92 ct = 15.6% larger

Analysis: A very large Fancy Intense Yellow radiant cut diamond featuring a step-cut facet alignment on the crown. The Inner-Grade is at its lowest, bordering on Fancy Yellow, with some prominent colorless areas visible in the face-up view

Quality Remark: Very low Inner-Grade

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Lot 147

Description: 10.2 ct, Fancy Intense Pink, Round, IF
High Auction Estimation: $1,176,471 pc
Price realized: $1,302,942 pc
GIA Rarity Diary
True Face-Up: Translates to the visual appearance of a 11.34 ct = 11.1% larger

Analysis: A Fancy Intense Pink round brilliant-cut diamond that features a completely colorless face-up, while it exhibits a strong body color, visible only when placed face-down or at a 45-degree angle through the table facet. Round brilliant diamonds cut in this manner typically do not exhibit their full potential unless they are repolished into a modified square shape, losing approximately 20% of their weight in the process. This diamond presents a rare opportunity to observe a fancy color diamond with a strong body color and a completely colorless face-up, attributed to the round brilliant facet alignment, originally designed to minimize color retention.

Quality Remark: Very low Color Dispersion

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Discover the IDU Grading Standard

Our pre-auction analysis leverages the IDU Grading Standard to evaluate fancy color diamonds, focusing on three key visual attributes not covered by GIA: Inner-Grade, Undertone, and Color Dispersion. These elements provide deeper insights into a diamond’s color intensity, hue influences, and color evenness—factors critical to its beauty and value. Additionally, our True Face-Up calibration reveals how a diamond’s carat weight translates to its visual presence.

Inner-Grade measures the saturation strength within the GIA-defined categories, determining the level of saturation. 

Grade 1 places the saturation in doubt, indicating it borders on the saturation below. 

Grade 2 is a weak saturation, 

Grade 3 refers to a solid saturation, 

Grade 4 borders on one saturation above. In the vivid category, 

Grade 4+ is reserved for exceptional saturation.

Color Dispersion examines literally how well the color mosaic is dispersed across the diamond’s face-up view. 

This aspect ranges from Grade 1, showing noticeable colorless areas, to Grade 4+, indicating perfect dispersion.

Undertone evaluates the subtle color influences within the diamond’s color, such as brightness or muted tones. 

The undertone grade reflects the diamond’s color sensation and how well it meets our expectations of the color. 

Grade 1 indicates a significant presence of another color. 

Grade 2 indicates a mild foreign sensation. 

Grade 3 indicates an insignificant undertone (most abundant). 

Grade 4 is the pure form of the color.

Grade 4+ is reserved for pink diamonds where the undertone enhances the primary color, making it exceptionally desirable.

For an in-depth exploration of our grading methodology and how it enhances the valuation of fancy color diamonds, we invite you to read the full article.