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Radiant|Lab Grown|IGI

1.23ct G SI1 Radiant Lab Grown Diamond

ID • G/SI1 • IGI LG514255275

Shape and cutting style on the report: Cut cornered rectangular modified brilliant

Certificate IGI LG514255275

Diamond specifications and retailer prices

From £501 GBP
As of November 6, 2026
Save £530 GBP (51%) vs most expensive(unlock to see where)
13 retailers carry this diamond
Most expensive: £1,787 GBP at NZ Jewellers · As of November 6, 2026
View at NZ Jewellers

About this 1.23ct lab-grown radiant diamond

This 1.23ct lab-grown radiant 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 LG514255275 or 514255275. Listed at 13 retailers as of November 4, 2026, with a 106% 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

1.23
Carat
G
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle41.2°
Pavilion angle32.3°
OriginLab Grown
Grading LabIGI
CertificateIGI LG514255275
Dimensions7.25 × 5.53 × 3.53 mm
L/W Ratio1.31
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
7.25 mm5.53 mm1.23 ctG / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG514255275
Side View
Table 61.5%Crown 41.2°Girdle: Slightly ThickPavilion 32.3°Culet: NoneDepth 63.8%

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: £1,007 GBP|Low: £501 GBP|High: £2,529 GBP|Avg: £1,040 GBP|-0.4%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
November 6, 2026
Retailer 3£501 GBP
Retailer 6£548 GBP
Retailer 9£613 GBP
Retailer 7£636 GBP
Retailer 4£770 GBP
Retailer 1£1,007 GBP
Retailer 8£1,030 GBP
Retailer 5£1,566 GBP
Retailer 2£2,489 GBP

42 data points across 9 retailers

13 retailers£501 GBP to £1,030 GBP

B+
Cheapest Retailer
-
£501 GBP
B
Retailer 2
-
£548 GBP
View
B
Retailer 3
-
£596 GBP
View
B
Retailer 4
-
£613 GBP
View
Final sale: no returns
B
Retailer 5
-
£636 GBP
View
Retailer 6
-
£636 GBP
View
Price last confirmed 26 days ago
B
Retailer 7
-
£770 GBP
View
B
Retailer 8
-
£1,007 GBP
View
B
Retailer 9
-
£1,030 GBP
View
Retailer 10
-
£1,566 GBP
View
Price under review
Most Expensive
NZ Jewellers
608f19aa-4b90-4042-a34e-5575f5ee5aa6 · Nov 6
£1,787 GBP
$2,392 USD
View
Price under review
10 more retailers have this diamond
Prices start from £501 GBPSave up to £530 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+
1.23ct Radiant
£501 GBP