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Round|Natural|IGI

1.21ct J SI1 Round Natural Diamond

EX • J/SI1 • IGI 670478896

Shape and cutting style on the report: Round brilliant

Certificate IGI 670478896

Diamond specifications and retailer prices

From £1,319 GBP
As of November 5, 2026
Save £1,232 GBP (48%) vs most expensive(unlock to see where)
16 retailers carry this diamond
Most expensive: £3,606 GBP at NZ Jewellers · As of September 21, 2026
View at NZ Jewellers

About this 1.21ct natural round diamond

This 1.21ct natural round sits in the classic one-carat band, graded J colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI 670478896. Listed at 16 retailers as of November 4, 2026, with a 93% 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
J
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34.4°
Pavilion angle40.8°
OriginNatural
Grading LabIGI
CertificateIGI 670478896
Dimensions6.86 × 6.91 × 4.19 mm
L/W Ratio1.01
Girdle conditionFaceted
Culet sizePointed
Cert comments
IDEAL CUT ROUND BRILLIANT
Top View
6.86 mm6.91 mm1.21 ctJ / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI 670478896
Side View
Table 58.0%Crown 34.4°Girdle: MediumPavilion 40.8°Culet: NoneDepth 60.9%

Caratlytics Score

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A
Excellent
Excellent quality and great value
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See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Nov 5
Current: £3,165 GBP|Low: £1,319 GBP|High: £3,606 GBP|Avg: £1,840 GBP|-12.2%
NZ Jewellers
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
November 6, 2026
Retailer 7£1,319 GBP
Retailer 8£1,398 GBP
Retailer 9£1,478 GBP
Retailer 10£1,478 GBP
Retailer 6£1,490 GBP
Retailer 2£1,594 GBP
Retailer 4£1,782 GBP
Retailer 3£1,979 GBP
Retailer 5£2,551 GBP
NZ Jewellers£3,165 GBP

29 data points across 10 retailers

16 retailers£1,319 GBP to £2,551 GBP

A
Cheapest Retailer
-
£1,319 GBP
A
Retailer 2
-
£1,398 GBP
View
Retailer 3
-
£1,478 GBP
View
Price last confirmed 56 days ago
Retailer 4
-
£1,478 GBP
View
Price last confirmed 44 days ago
Retailer 5
-
£1,478 GBP
View
Price last confirmed 15 days ago
A
Retailer 6
-
£1,490 GBP
View
Retailer 7
-
£1,514 GBP
View
Price last confirmed 21 days ago
A
Retailer 8
-
£1,594 GBP
View
Retailer 9
-
£1,706 GBP
View
Price last confirmed 60 days ago
Retailer 10
-
£1,706 GBP
View
Price last confirmed 45 days ago
B+
Retailer 11
-
£1,782 GBP
View
B+
Retailer 12
-
£1,979 GBP
View
B
Retailer 13
-
£2,551 GBP
View
Retailer 14
-
£3,165 GBP
View
Price last confirmed 17 days ago
Retailer 15
-
£3,606 GBP
View
Price last confirmed 57 days ago
Most Expensive
NZ Jewellers
4037a78b-fd2d-45af-aade-16b6d7d538be · Sep 21
£3,606 GBP
$4,826 USD
View
Price last confirmed 46 days ago
15 more retailers have this diamond
Prices start from £1,319 GBPSave up to £1,232 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.

A
1.21ct Round
£1,319 GBP