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Round|Lab Grown|IGI

1.23ct G SI1 Round Lab Grown Diamond

ID • G/SI1 • IGI LG488131917

Shape and cutting style on the report: Round brilliant

Certificate IGI LG488131917

Diamond specifications and retailer prices

From £656 GBP
As of November 5, 2026
Save £565 GBP (46%) vs most expensive(unlock to see where)
12 retailers carry this diamond
Most expensive: £1,692 GBP at Friendly Diamonds · As of November 4, 2026
View at Friendly Diamonds

About this 1.23ct lab-grown round diamond

This 1.23ct 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 LG488131917 or 488131917. Listed at 12 retailers as of November 4, 2026, with a 86% 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 angle34°
Pavilion angle41.2°
OriginLab Grown
Grading LabIGI
CertificateIGI LG488131917
Dimensions6.93 × 6.90 × 4.24 mm
L/W Ratio1.00
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
6.93 mm6.90 mm1.23 ctG / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG488131917
Side View
Table 57.5%Crown 34°Girdle: THN-MEDPavilion 41.2°Culet: NoneDepth 61.3%

Caratlytics Score

How it works →
B
Good
Decent quality, room for better deals
Unlock full score analysis
See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Nov 5
Current: £1,692 GBP|Low: £629 GBP|High: £2,889 GBP|Avg: £1,124 GBP
Friendly Diamonds
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
November 6, 2026
Retailer 4£656 GBP
Retailer 5£691 GBP
Retailer 8£734 GBP
Retailer 6£761 GBP
Retailer 9£761 GBP
Retailer 10£892 GBP
Retailer 2£1,147 GBP
Retailer 7£1,221 GBP
Friendly Diamonds£1,692 GBP
Retailer 3£2,843 GBP

43 data points across 10 retailers

12 retailers£656 GBP to £1,221 GBP

B
Cheapest Retailer
-
£656 GBP
B
Retailer 2
-
£691 GBP
View
B
Retailer 3
-
£713 GBP
View
B
Retailer 4
-
£734 GBP
View
Final sale: no returns
Retailer 5
-
£761 GBP
View
Price last confirmed 25 days ago
B
Retailer 6
-
£761 GBP
View
B
Retailer 7
-
£892 GBP
View
B
Retailer 8
-
£1,147 GBP
View
B
Retailer 9
-
£1,221 GBP
View
Most Expensive
Friendly Diamonds
1594928 · Nov 4
£1,692 GBP
$2,277 USD
View
Price under review
9 more retailers have this diamond
Prices start from £656 GBPSave up to £565 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 Round
£656 GBP