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Radiant|Lab Grown|IGI

1.51ct G SI1 Radiant Lab Grown Diamond

ID • G/SI1 • IGI LG508137718

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

Certificate IGI LG508137718

Diamond specifications and retailer prices

From £732 GBP
As of November 6, 2026
Save £1,651 GBP (69%) vs most expensive(unlock to see where)
12 retailers carry this diamond
Most expensive: £2,526 GBP at NZ Jewellers · As of November 6, 2026
View at NZ Jewellers

About this 1.51ct lab-grown radiant diamond

This 1.51ct lab-grown radiant sits in the one-and-a-half to two carat band, graded G colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG508137718 or 508137718. Listed at 12 retailers as of November 4, 2026, with a 226% 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

1.51
Carat
G
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle37.8°
Pavilion angle30.4°
OriginLab Grown
Grading LabIGI
CertificateIGI LG508137718
Dimensions7.68 × 5.99 × 3.66 mm
L/W Ratio1.28
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
7.68 mm5.99 mm1.51 ctG / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG508137718
Side View
Table 69.5%Crown 37.8°Girdle: STK-THKPavilion 30.4°Culet: NoneDepth 61.1%

Caratlytics Score

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

Price History

Last verified: Nov 6
Current: £1,885 GBP|Low: £732 GBP|High: £3,900 GBP|Avg: £1,862 GBP|-2.9%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
November 6, 2026
Retailer 3£732 GBP
Retailer 5£1,162 GBP
Retailer 8£1,300 GBP
Retailer 6£1,348 GBP
Retailer 1£1,885 GBP
Retailer 7£2,121 GBP
Retailer 4£2,383 GBP
Retailer 2£3,838 GBP

44 data points across 8 retailers

12 retailers£732 GBP to £2,383 GBP

B+
Cheapest Retailer
-
£732 GBP
B
Retailer 2
-
£1,162 GBP
View
B
Retailer 3
-
£1,264 GBP
View
B
Retailer 4
-
£1,300 GBP
View
Final sale: no returns
Retailer 5
-
£1,348 GBP
View
Price last confirmed 26 days ago
B
Retailer 6
-
£1,348 GBP
View
B
Retailer 7
-
£1,476 GBP
View
B
Retailer 8
-
£1,885 GBP
View
B
Retailer 9
-
£2,121 GBP
View
B
Retailer 10
-
£2,383 GBP
View
Most Expensive
NZ Jewellers
ca34d291-6431-4e06-b846-08ff7aaab054 · Nov 6
£2,526 GBP
$3,381 USD
View
Price under review
10 more retailers have this diamond
Prices start from £732 GBPSave up to £1,651 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+
1.51ct Radiant
£732 GBP