CaratHunter
Plans
Cushion|Lab Grown|IGI

4.09ct F SI1 Cushion Lab Grown Diamond

ID • F/SI1 • IGI LG677556271

Shape and cutting style on the report: Cushion brilliant

Certificate IGI LG677556271

Diamond specifications and retailer prices

From £363 GBP
As of November 2, 2026
Save £1,399 GBP (79%) vs most expensive(unlock to see where)
10 retailers carry this diamond
Most expensive: £1,762 GBP at Rare Carat · As of October 28, 2026
View at Rare Carat

About this 4.09ct lab-grown cushion diamond

This 4.09ct lab-grown cushion sits in the three to five carat band, graded F colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG677556271 or 677556271. Listed at 10 retailers as of October 28, 2026, with prices from £363 to £1,762, a £1,399 spread on the same certified stone. Rare Carat lists it at £1,762. 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

4.09
Carat
F
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle33.8°
Pavilion angle38.2°
OriginLab Grown
Grading LabIGI
CertificateIGI LG677556271
Dimensions10.61 × 8.73 × 5.91 mm
L/W Ratio1.22
Girdle conditionFaceted
Culet sizePointed
Cert comments
This Laboratory Grown Diamond was created by Chemical Vapor Deposition (CVD) growth process Type IIa
Top View
10.61 mm8.73 mm4.09 ctF / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG677556271
Side View
Table 61.0%Crown 33.8°Girdle: MED-STKPavilion 38.2°Culet: NoneDepth 67.7%

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 2
Current: £2,606 GBP|Low: £363 GBP|High: £4,292 GBP|Avg: £1,440 GBP
Rare Carat
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
November 2, 2026
Retailer 2£363 GBP
Retailer 10£467 GBP
Retailer 7£529 GBP
Retailer 6£637 GBP
Retailer 12£660 GBP
Retailer 9£678 GBP
Retailer 5£692 GBP
Retailer 11£870 GBP
Retailer 8£1,556 GBP
Rare Carat£2,606 GBP
Retailer 3£3,534 GBP
Retailer 4£4,292 GBP

6 data points across 12 retailers

10 retailers£363 GBP to £1,762 GBP

A
Cheapest Retailer
-
£363 GBP
A
Retailer 2
-
£467 GBP
HK$4,900 HKD
View
A
Retailer 3
-
£529 GBP
$710 USD
View
A
Retailer 4
-
£637 GBP
€814 EUR
View
B+
Retailer 5
-
£660 GBP
$886 USD
View
A
Retailer 6
-
£678 GBP
$910 USD
View
A
Retailer 7
-
£692 GBP
View
A
Retailer 8
-
£870 GBP
$1,168 USD
View
B
Retailer 9
-
£1,556 GBP
View
Most Expensive
B
Rare Carat
KI2715562KF677 · Oct 28
£1,762 GBP
$2,365 USD
View
9 more retailers have this diamond
Prices start from £363 GBPSave up to £1,399 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
4.09ct Cushion
£363 GBP