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Cushion|Lab Grown|IGI

4.20ct D FL Cushion Lab Grown Diamond

ID • D/FL • IGI LG846663139

Shape and cutting style on the report: Cushion modified brilliant

Certificate IGI LG846663139

Diamond specifications and retailer prices

From £3,273 GBP
As of October 30, 2026
Save £17,096 GBP (84%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: £20,369 GBP at With Clarity · As of October 31, 2026
View at With Clarity

About this 4.2ct lab-grown cushion diamond

This 4.2ct lab-grown cushion sits in the three to five carat band, graded D colour (colourless) and FL clarity (flawless or internally-flawless), with a top-tier cut grade and certified by IGI LG846663139 or 846663139. Listed at 9 retailers as of October 30, 2026, with prices from £3,273 to £20,369, a £17,096 spread on the same certified stone. With Clarity lists it at £20,369. Lab-grown prices in the 2ct and up range have fallen 40 to 60% over the last 18 months. Use the cross-retailer spread above to find the lowest current listing.

The 4Cs

4.20
Carat
D
Colour
FL
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle31.7°
Pavilion angle35.4°
OriginLab Grown
Grading LabIGI
CertificateIGI LG846663139
Dimensions11.69 × 8.30 × 5.51 mm
L/W Ratio1.41
Girdle conditionFaceted
Cert comments
As Grown - No indication of post-growth treatment This Laboratory Grown Diamond was created by High Pressure High Temperature (HPHT) growth process Type II
Top View
11.69 mm8.30 mm4.20 ctD / FL
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG846663139
Side View
Table 61.0%Crown 31.7°Girdle: STK-THKPavilion 35.4°Culet: NoneDepth 66.4%

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: Oct 30
Current: £3,944 GBP|Low: £3,027 GBP|High: £21,998 GBP|Avg: £7,872 GBP|+7.5%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
With Clarity
October 31, 2026
Retailer 5£3,273 GBP
Retailer 1£3,944 GBP
Retailer 2£4,835 GBP
Retailer 7£5,621 GBP
Retailer 6£7,177 GBP
Retailer 3£7,197 GBP
Retailer 8£7,527 GBP
Retailer 4£11,792 GBP
With Clarity£20,369 GBP

7 data points across 9 retailers

9 retailers£3,273 GBP to £20,369 GBP

A
Cheapest Retailer
-
£3,273 GBP
A
Retailer 2
-
£3,944 GBP
$5,285 USD
View
A
Retailer 3
-
£4,835 GBP
$6,479 USD
View
A
Retailer 4
-
£5,621 GBP
$7,531 USD
View
B+
Retailer 5
-
£7,177 GBP
€9,158 EUR
View
B+
Retailer 6
-
£7,197 GBP
$9,643 USD
View
B+
Retailer 7
-
£7,527 GBP
View
B+
Retailer 8
-
£11,792 GBP
$15,800 USD
View
Most Expensive
B
With Clarity
846663139 · Oct 31
£20,369 GBP
$27,292 USD
View
8 more retailers have this diamond
Prices start from £3,273 GBPSave up to £17,096 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
4.20ct Cushion
£3,273 GBP