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Round|Natural|GIA

1.21ct H SI1 Round Natural Diamond

EX • H/SI1 • GIA 6455803337

Certificate GIA 6455803337

Diamond specifications and retailer prices

From £2,869 GBP
As of November 6, 2026
Save £3,400 GBP (54%) vs most expensive(unlock to see where)
15 retailers carry this diamond
Most expensive: £8,641 GBP at Diamond Quarter · As of November 5, 2026
View at Diamond Quarter

About this 1.21ct natural round diamond

This 1.21ct natural round sits in the classic one-carat band, graded H colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 6455803337. Listed at 15 retailers as of November 5, 2026, with a 119% spread between the cheapest and most expensive listing. That is exactly the kind of price-discovery gap Carat Hunter was built to surface. 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

1.21
Carat
H
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34°
Pavilion angle40.8°
OriginNatural
Grading LabGIA
CertificateGIA 6455803337
Dimensions6.85 × 6.80 × 4.21 mm
L/W Ratio1.01
Star length50%
Lower girdle75%
Top View
6.85 mm6.80 mm1.21 ctH / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 6455803337
Side View
Table 57.0%Crown 34°Girdle: MED-STKPavilion 40.8°Culet: NoneDepth 61.7%

Caratlytics Score

How it works →
B+
Very Good
Strong quality and value balance
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See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Nov 6
Current: £3,520 GBP|Low: £2,869 GBP|High: £5,800 GBP|Avg: £3,790 GBP|+1.1%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
November 6, 2026
Retailer 8£2,869 GBP
Retailer 5£2,891 GBP
Retailer 7£3,093 GBP
Retailer 9£3,260 GBP
Retailer 1£3,520 GBP
Retailer 6£3,627 GBP
Retailer 3£4,045 GBP
Retailer 2£4,390 GBP
Retailer 4£5,715 GBP

45 data points across 9 retailers

15 retailers£2,869 GBP to £6,269 GBP

B+
Cheapest Retailer
-
£2,869 GBP
B+
Retailer 2
-
£2,891 GBP
View
B+
Retailer 3
-
£3,093 GBP
View
B+
Retailer 4
-
£3,260 GBP
View
Retailer 5
-
£3,260 GBP
View
Price last confirmed 8 days ago
B+
Retailer 6
-
£3,260 GBP
View
B+
Retailer 7
-
£3,520 GBP
View
Retailer 8
-
£3,627 GBP
View
Price last confirmed 28 days ago
B
Retailer 9
-
£3,762 GBP
View
Retailer 10
-
£3,973 GBP
View
Price last confirmed 14 days ago
B
Retailer 11
-
£4,045 GBP
View
B
Retailer 12
-
£4,390 GBP
View
B
Retailer 13
-
£5,715 GBP
View
B
Retailer 14
-
£6,269 GBP
View
Most Expensive
Diamond Quarter
1.21SI1H64372F45N · Nov 5
£8,641 GBP
View
Price under review
14 more retailers have this diamond
Prices start from £2,869 GBPSave up to £3,400 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+
1.21ct Round
£2,869 GBP