CaratHunter
Plans
Marquise|Lab Grown|IGI

1.21ct E SI1 Marquise Lab Grown Diamond

EX • E/SI1 • IGI LG816673640

Shape and cutting style on the report: Marquise brilliant

Certificate IGI LG816673640

Diamond specifications and retailer prices

From £140 GBP
As of November 4, 2026
Save £587 GBP (81%) vs most expensive(unlock to see where)
8 retailers carry this diamond
Most expensive: £727 GBP at MOH London · As of November 1, 2026
View at MOH London

About this 1.21ct lab-grown marquise diamond

This 1.21ct lab-grown marquise sits in the classic one-carat band, graded E colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG816673640 or 816673640. Listed at 8 retailers as of November 1, 2026, with prices from £140 to £727, a £587 spread on the same certified stone. MOH London lists it at £727. 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
E
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle33.3°
Pavilion angle40.5°
OriginLab Grown
Grading LabIGI
CertificateIGI LG816673640
Dimensions11.44 × 5.59 × 3.44 mm
L/W Ratio2.05
Cert comments
This Laboratory Grown Diamond was created by Chemical Vapor Deposition (CVD) growth process Type IIa
Top View
11.44 mm5.59 mm1.21 ctE / SI1
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG816673640
Side View
Table 61.0%Crown 33.3°Girdle: MED-STKPavilion 40.5°Culet: NoneDepth 61.5%

Caratlytics Score

How it works →
A
Excellent
Excellent quality and great value
Unlock full score analysis
See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Nov 4
Current: £727 GBP|Low: £137 GBP|High: £728 GBP|Avg: £371 GBP|+1.7%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
November 6, 2026
Retailer 5£140 GBP
Retailer 3£200 GBP
Retailer 2£273 GBP
Retailer 7£279 GBP
Retailer 4£295 GBP
Retailer 6£528 GBP
Retailer 8£540 GBP
MOH London£727 GBP

17 data points across 8 retailers

8 retailers£140 GBP to £727 GBP

A
Cheapest Retailer
-
£140 GBP
Final sale: no returns
A
Retailer 2
-
£200 GBP
View
A
Retailer 3
-
£273 GBP
View
A
Retailer 4
-
£279 GBP
View
B+
Retailer 5
-
£295 GBP
View
B
Retailer 6
-
£528 GBP
View
B
Retailer 7
-
£540 GBP
View
Most Expensive
B
MOH London
LG816673640 · Nov 1
£727 GBP
View
7 more retailers have this diamond
Prices start from £140 GBPSave up to £587 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.

A
1.21ct Marquise
£140 GBP