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Round|Lab Grown|IGI

1.21ct F SI1 Round Lab Grown Diamond

ID • F/SI1 • IGI LG487108246

Shape and cutting style on the report: Round brilliant

Certificate IGI LG487108246

Diamond specifications and retailer prices

From £687 GBP
As of November 5, 2026
Save £595 GBP (46%) vs most expensive(unlock to see where)
11 retailers carry this diamond
Most expensive: £1,780 GBP at Friendly Diamonds · As of November 4, 2026
View at Friendly Diamonds

About this 1.21ct lab-grown round diamond

This 1.21ct lab-grown round sits in the classic one-carat band, graded F colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG487108246 or 487108246. Listed at 11 retailers as of November 4, 2026, with a 87% 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
F
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle35.2°
Pavilion angle40.2°
OriginLab Grown
Grading LabIGI
CertificateIGI LG487108246
Dimensions6.90 × 6.87 × 4.17 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
6.90 mm6.87 mm1.21 ctF / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG487108246
Side View
Table 58.5%Crown 35.2°Girdle: MediumPavilion 40.2°Culet: NoneDepth 60.6%

Caratlytics Score

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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: £1,780 GBP|Low: £687 GBP|High: £2,746 GBP|Avg: £1,276 GBP
Friendly Diamonds
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
November 6, 2026
Retailer 5£687 GBP
Retailer 8£751 GBP
Retailer 9£772 GBP
Retailer 7£800 GBP
Retailer 4£1,217 GBP
Retailer 6£1,283 GBP
Retailer 2£1,491 GBP
Friendly Diamonds£1,780 GBP
Retailer 3£2,707 GBP

46 data points across 9 retailers

11 retailers£687 GBP to £1,283 GBP

B
Cheapest Retailer
-
£687 GBP
B
Retailer 2
-
£751 GBP
View
B
Retailer 3
-
£772 GBP
View
Final sale: no returns
Retailer 4
-
£790 GBP
View
Price last confirmed 66 days ago
Retailer 5
-
£800 GBP
View
Price last confirmed 25 days ago
B
Retailer 6
-
£930 GBP
View
B
Retailer 7
-
£1,217 GBP
View
B
Retailer 8
-
£1,283 GBP
View
Retailer 9
-
£1,491 GBP
View
Price under review
Most Expensive
Friendly Diamonds
1594948 · Nov 4
£1,780 GBP
$2,383 USD
View
Price under review
9 more retailers have this diamond
Prices start from £687 GBPSave up to £595 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
£687 GBP