Important Jewels
Pre-Auction Analysis: March 8th, 2023, Sotheby’s New York, Important Jewels
Our Sotheby’s New York 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 stones with exceptional characteristics. Stones 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.
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: 25
Description: 4.72 ct, Fancy Yellow, Radiant, VVS2
High Auction Estimation: $7,415 pc
Price realized: $8,073 pc
Rarity: 21-25 diamonds yearly – Share this rarity result – Here
GIA Report: View
Analysis: A 4.72 carat radiant cut diamond with a colorless crown. Its inner-grade is solid and it has no significant in its hue. Given recent cutting trends in the market, it is quite rare to find fancy color diamonds with a low depth percentage (58%) and a large face-up view that corresponds to a larger carat weight.
Visual Assets:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
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Lot: 39
Description: 1.26 ct, Fancy Deep Yellow, Pear, SI1
High Auction Estimation: $23,809 pc
Price realized: $9,576 pc
Rarity: 4-8 diamonds yearly – Share this rarity result – Here
GIA Report: View
Analysis: A 1.26 carat fancy deep yellow pear-shaped diamond with a typical warm undertone and a strong inner-grade. The diamond’s appearance corresponds to a larger carat weight.
Visual Assets:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………2
Total Visual Score….8 out of 12
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Lot: 58
Description 2.08: 2.08 ct, Fancy Deep Yellowish Orange, Round, I1
Description 2.00: 2.00 ct, Fancy Deep Yellowish Orange, Round, SI2
Description 1.11: 1.11 ct, Fancy Deep Yellowish Orange, Round, SI2
Description 1.01: 1.01 ct, Fancy Deep Yellowish Orange, Round, SI2
High Auction Estimation: $12,903 pc
Price realized: $7,784 pc
GIA Report 2.08: View
GIA Report 2.00: View
GIA Report 1.11: View
GIA Report 1.01: View
Analysis of all 4 diamonds: Four round fancy deep yellowish orange diamonds with a typical clarity that ranges from SI2 to I1, resulting from clouds in the center of each stone.
Visual Assets for 4 diamonds:
Visual Assets 2.08:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
Visual Assets 2.00:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
Visual Assets 1.11:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
Visual Assets 1.01:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
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Lot: 111
Description: 0.90 ct, Fancy Deep Pink, Emerald, I1
High Auction Estimation: $133,333 pc
Price realized: $155,223 pc
GIA Report: View
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Analysis: A fancy deep pink that was cut and polished without any modification, resulting in a large colorless area. The I1 clarity grade is due to a large feather crossing the crown.
Visual Assets:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
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Lot: 130 – color report only
Description: 4.03 ct, Fancy Deep Yellow, Cushion
High Auction Estimation: $37,220pc
Withdrawn from auction
GIA Report: View
Analysis: A deep yellow cushion-cut diamond with a warm undertone and a color-only report. The diamond has a large inclusion, estimated to be an I1 clarity and appears somewhat opaque. Because the stone is completely covered in yellow gold from the girdle to the culet, we were unable to grade the diamond accurately.
Visual Assets:
Inner Grade..……………….N/A
Color Dispersion.………N/A
Undertone..…………………N/A
Total Visual Score…. N/A
Quality remark: color-only report, opaque
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Lot: 131
Description: 1.01 ct, Fancy Intense Green, Cushion, I1
High Auction Estimation: $247,524 pc
Price realized: $69,159 pc
GIA Report: View
Analysis: A 1.01 carat fancy intense green cushion with fair symmetry and I1 clarity. The colorless patches on the crown are prominent and the inner-grade is very low.
Visual Assets:
Inner Grade..……………….1
Color Dispersion.………1
Undertone..…………………3
Total Visual Score….5 out of 12
Quality remark: I1, fair symmetry and low inner-grade
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Lot: 133
Description: 1.81 ct, Fancy Green, Cushion, SI2
High Auction Estimation: $44,198 pc
Price realized: $29,470 pc
GIA Report: View
Analysis: A 1.81 carat fancy green cushion-cut diamond with an SI2 clarity. The inner-grade is low, as are the other two visual parameters. However, the diamond’s surface area face-up suggests a larger carat weight. It is important to note that the diamond is completely covered underneath, and the visual analysis should be taken with limitations.
Visual Assets:
Inner Grade..……………….2
Color Dispersion.………2
Undertone..…………………2
Total Visual Score….6 out of 12
Quality remark: SI2 clarity, low visual parameters
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Lot: 134 – color report only
Description: 5.26 ct, Fancy Purplish Pink, Oval
High Auction Estimation: $104,562 pc
Withdrawn from auction
GIA Report: View
Analysis: A fancy purplish pink oval with a color-only report. The diamond appears to have a low clarity grade (I1) and the inner-grade appears very strong, probably due to a pink reflection from the gold underneath. According to the surface area, the diamond corresponds to a larger carat weight.
Visual Assets:
Inner Grade..……………….4
Color Dispersion.………3
Undertone..…………………4
Total Visual Score….11 out of 12
Quality remark: color-only report, low clarity
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Lot: 135 – color report only
Description: 1.48 ct, Fancy Grayish Blue, Radiant
High Auction Estimation: $101,351 pc
Price realized: $41,190 pc
GIA Report: View
Analysis: A 1.48 carat fancy grayish blue radiant cut with a color-only report from 2011. The diamond has a low clarity (I1) and low visual assets.
Visual Assets:
Inner Grade..……………….2
Color Dispersion.………2
Undertone..…………………1
Total Visual Score….5 out of 12
Quality remark: color-only report, low clarity
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Lot: 136
Description: 1.78 ct, Fancy Deep Grayish Yellowish Green, Cushion, VS1
Description: 1.64, ct, Fancy Green, Cushion, I1
High Auction Estimation: $160,818 pc
Price realized: $24,138 pc
GIA Report 1.78: View
GIA Report 1.64: View
Analysis: A 1.78 fancy dark grayish yellowish green diamond with a few colorless patches on the crown. Fancy color diamonds with a deep grade like this one will naturally have a strong inner-grade. A fancy green 1.64 carat cushion-cut diamond with an I1 clarity under the table. The diamond has a strong green fluorescence.
Visual Assets 1.78:
Inner Grade..……………….3
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….9 out of 12
Visual Assets 1.64:
Inner Grade..……………….2
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….8 out of 12
Quality remarks: SI2 and I1 clarity.
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Lot: 151
Description: 4.74 ct, Fancy Intense Yellow, Radiant, SI1
High Auction Estimation: $10,548 pc
Price realized: $11,254 pc
Rarity: 4-9 diamonds yearly – Share this rarity result – Here
GIA Report: View
Analysis: A 4.74 fancy intense yellow radiant cut with an SI1 clarity,
Very few colorless patches are seen through the crown, and no green or brown undertone is visible in the hue.
Visual Assets:
Inner Grade..……………….3
Color Dispersion.………4
Undertone..…………………4
Total Visual Score….11 out of 12
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Lot: 266
Description: 1.12 ct, Fancy Intense Blue, Pear, SI2
High Auction Estimation: $580,357 pc
Didn’t reach the minimum
Rarity: Once every 1-2 years – Share this rarity result – Here
GIA Report: View
Analysis: A 1.12 fancy intense blue pear-shaped diamond with multiple feathers underneath the table facet resulting in an SI2 clarity. The diamond is cut with minimal modification and has a large colorless area in its center. The inner-grade is weak relative to an intense blue.
Visual Assets:
Inner Grade..……………….2
Color Dispersion.………2
Undertone..…………………3
Total Visual Score….7 out of 12
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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 the grade 1, while a stone that exhibits its face-up view with no colorless patches will receive the grade 4+. Unlike the first two elements, the color dispersion is not a gemological quality and is the result of cutter proficiency.
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