Round|Natural|GIA

20.66ct H SI1 Round Natural Diamond

EX • H/SI1 • GIA 5234238312

Certificate GIA 5234238312

Diamond specifications and retailer prices

From £597,996 GBP
$802,475 USD
As of November 1, 2026
Save £163,828 GBP (22%) vs most expensive(unlock to see where)
4 retailers carry this diamond
Most expensive: £761,824 GBP at Yorxs · As of November 1, 2026
View at Yorxs

About this 20.66ct natural round diamond

This 20.66ct natural round sits in the over five carat band, graded H colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 5234238312. Listed at 4 retailers as of November 1, 2026, with prices from £597,996 to £761,824, a £163,828 spread on the same certified stone. Yorxs lists it at £761,824. SI-grade stones are eye-clean roughly 60 to 70% of the time at this carat range. Check the inclusion plot on the cert and ask the retailer for high-resolution video before buying.

The 4Cs

20.66
Carat
H
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceStrong
Crown angle32.5°
Pavilion angle41.8°
OriginNatural
Grading LabGIA
CertificateGIA 5234238312
Dimensions17.54 × 17.39 × 10.99 mm
L/W Ratio1.01
Star length45%
Lower girdle80%
Top View
17.54 mm17.39 mm20.66 ctH / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceStrong
CertificateGIA 5234238312
Side View
Table 57.0%Crown 32.5°Girdle: STK-STKPavilion 41.8°Culet: NoneDepth 62.9%

Caratlytics Score

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B
Good
Decent quality, room for better deals
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Price History

Last verified: Nov 1
Current: £598,923 GBP|Low: £579,639 GBP|High: £765,222 GBP|Avg: £634,730 GBP|-0.9%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Yorxs
November 1, 2026
Retailer 3£586,864 GBP
Retailer 2£597,996 GBP
Retailer 1£598,923 GBP
Retailer 4£623,888 GBP
Yorxs£761,824 GBP

29 data points across 5 retailers

4 retailers£597,996 GBP to £761,824 GBP

Retailer 1
-
£586,864 GBP
A$1,211,593 AUD
Price last confirmed 29 days ago
B
Retailer 2
-
£597,996 GBP
$802,475 USD
View
B
Retailer 3
-
£598,923 GBP
View
Most Expensive
B
Yorxs
4438E07F5 · Nov 1
£761,824 GBP
€973,640 EUR
View
3 more retailers have this diamond
Prices start from £597,996 GBPSave up to £163,828 GBP

Carat Hunter is not affiliated with, endorsed by, or sponsored by any retailer listed. Retailer information is from publicly available sources and may not be current. Verify details directly with the retailer before purchasing. Return terms as we hold them. Check the retailer's own returns page before you buy.

B
20.66ct Round
£597,996 GBP