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Round|Lab Grown|IGI

1.21ct G SI1 Round Lab Grown Diamond

EX • G/SI1 • IGI LG598387229

Shape and cutting style on the report: Round brilliant

Certificate IGI LG598387229

Diamond specifications and retailer prices

From £343 GBP
As of November 1, 2026
Save £781 GBP (69%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: £1,124 GBP at MOH London · As of November 5, 2026
View at MOH London

About this 1.21ct lab-grown round diamond

This 1.21ct lab-grown round sits in the classic one-carat band, graded G colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG598387229 or 598387229. Listed at 9 retailers as of November 1, 2026, with prices from £343 to £1,124, a £781 spread on the same certified stone. MOH London lists it at £1,124. 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
G
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle32.7°
Pavilion angle41.2°
OriginLab Grown
Grading LabIGI
CertificateIGI LG598387229
Dimensions6.94 × 6.88 × 4.17 mm
L/W Ratio1.01
Girdle conditionFaceted
Culet sizePointed
Cert comments
This Laboratory Grown Diamond was created by Chemical Vapor Deposition (CVD) growth process and may include post-growth treatment Type IIa
Top View
6.94 mm6.88 mm1.21 ctG / SI1
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG598387229
Side View
Table 60.0%Crown 32.7°Girdle: MediumPavilion 41.2°Culet: NoneDepth 60.3%

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 1
Current: £1,124 GBP|Low: £181 GBP|High: £1,140 GBP|Avg: £426 GBP|-0.3%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
November 6, 2026
Retailer 11£218 GBP
Retailer 12£254 GBP
Retailer 3£263 GBP
Retailer 4£277 GBP
Retailer 10£281 GBP
Retailer 8£343 GBP
Retailer 5£397 GBP
Retailer 6£409 GBP
Retailer 9£458 GBP
Retailer 2£490 GBP
Retailer 7£863 GBP
MOH London£1,124 GBP

37 data points across 12 retailers

9 retailers£343 GBP to £1,124 GBP

B+
Cheapest Retailer
-
£343 GBP
B+
Retailer 2
-
£397 GBP
View
B
Retailer 3
-
£409 GBP
View
B+
Retailer 4
-
£458 GBP
View
B
Retailer 5
-
£490 GBP
View
B
Retailer 6
-
£863 GBP
View
Retailer 7
-
£903 GBP
View
Price last confirmed 46 days ago
B
Retailer 8
-
£938 GBP
View
Most Expensive
B
MOH London
LG598387229 · Nov 5
£1,124 GBP
View
8 more retailers have this diamond
Prices start from £343 GBPSave up to £781 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
£343 GBP