The Hong Kong Jewels
Our Phillips The Hong Kong 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 551
Description: 1.79 ct, Fancy Vivid Yellow, Pear, VS2
True Face-Up: Appears ~16.9% larger than the average Pear shape in this weight.
Analysis: A 1.79-carat Fancy Vivid Yellow pear-shape diamond with a low inner-grade and no prominent green or brown undertone. The stone’s face-up appearance creates the optical illusion of being 2.10 carats, a feature that commands a premium. Please note that the report is dated 2011.
High Auction Estimation: $11,173 pc
Price Realized: $9,068 pc
Visual Assets:
Inner Grade..……………….1
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….7 out of 12
Quality Remark: Low inner grade
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Lot 554
Description: 2.65 ct, Fancy Intense Orangy Pink, Pear, VS1
True Face-Up: Appears ~13.2% larger than the average Pear shape in this weight.
Analysis: A 2.65-carat Fancy Intense orangy-pink pear-shaped diamond with a low inner-grade and a color sensation that aligns with expectations for a pink diamond with an orange modifier. Colorless patches are visible on the wider side of the crown. According to the Diary Report, its face-up appearance matches that of a 3-carat diamond, marking an important aspect of its value.
High Auction Estimation: $150,943 pc
Price Realized: $140,871 pc
Visual Assets:
Inner Grade..……………….2
Color Dispersion.………3
Undertone..…………………3
Total Visual Score….8 out of 12
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Lot 579
Description: 15.51 ct, Fancy Vivid Yellow, Round, VS2
True Face-Up: Appears true to its carat weight
Analysis: A very large vivid yellow Round Brilliant cut diamond with exceptional rarity, notably due to its shape. The low color inner-grade required a deviation from traditional facet alignment to achieve the vivid saturation. This adaptation is evident in the diamond’s high crown and 65% depth, an unusual architecture for a round brilliant. Altering angles in this way funnels most of the color beneath the table, effectively draining the crown of its color. Such a strategic adjustment enables achieving vivid saturation, especially when the inner-grade is borderline. No green or brown undertone is visible in the hue.
High Auction Estimation: $80,593 pc
Price Realized: $73,253 pc
Visual Assets:
Inner Grade..……………….1
Color Dispersion.………1
Undertone..…………………3
Total Visual Score….5 out of 12
Quality Remark: Low inner-grade and dispersion
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Lot 585
Description: 1.38 ct, Fancy Vivid Purplish Pink, Cushion, SI2
True Face-Up: The Diamond’s face-up view appears true to its carat weight
Analysis: A Fancy Vivid purplish-pink cushion cut with high color dispersion and a pleasant color sensation. Graining in pink diamonds is quite common and usually doesn’t affect the price. However, in this case, it seems to reduce the light’s translucency, giving the diamond a misty appearance. The clarity grade is based on a scattered group of crystals located under the table.
High Auction Estimation: $326,087 pc
Price Realized: Didn’t reach the minimum
Visual Assets:
Inner Grade..……………….2
Color Dispersion.………4
Undertone..…………………3
Total Visual Score….9 out of 12
Quality Remark: Hazy due to graining and SI2 clarity
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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, providing insights into the color’s intensity and richness. From Grade 1, indicating the faintest saturation, to Grade 4+, reserved for the most vivid saturation levels, this grading reveals the depth of a diamond’s color.
Color Dispersion examines how evenly the color is distributed across the diamond’s face-up view. This aspect ranges from Grade 1, showing noticeable colorless areas, to Grade 4+, indicating a flawless color spread.
Undertone evaluates the subtle hue influences within the diamond’s color. The undertone grade reflects the diamond’s color fidelity and its alignment with the desirable aesthetic standards. From Grade 1, indicating a significant presence of altering hues that might dilute the primary color’s intensity. to Grade 4+, reserved for diamonds where the undertone enhances the primary color, making it exceptionally desirable.
Our innovative True Face-Up calibration grade also offers invaluable insights into how a diamond’s carat weight is presented visually, adding another dimension to our comprehensive analysis.
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.