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Cushion|Lab Grown|IGI

4.21ct D FL Cushion Lab Grown Diamond

ID • D/FL • IGI LG780662156

Shape and cutting style on the report: Antique cushion cut

Certificate IGI LG780662156

Diamond specifications and retailer prices

From £3,058 GBP
$4,097 USD
As of October 29, 2026
Save £8,843 GBP (74%) vs most expensive(unlock to see where)
10 retailers carry this diamond
Most expensive: £11,901 GBP at MOH London · As of October 29, 2026
View at MOH London

About this 4.21ct lab-grown cushion diamond

This 4.21ct 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 LG780662156 or 780662156. Listed at 10 retailers as of October 29, 2026, with prices from £3,058 to £11,901, a £8,843 spread on the same certified stone. MOH London lists it at £11,901. 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

4.21
Carat
D
Colour
FL
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle36.5°
Pavilion angle42.7°
OriginLab Grown
Grading LabIGI
CertificateIGI LG780662156
Dimensions10.81 × 8.68 × 5.88 mm
L/W Ratio1.25
Girdle conditionFaceted
Culet sizeLarge
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
10.81 mm8.68 mm4.21 ctD / FL
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG780662156
Side View
Table 56.0%Crown 36.5°Girdle: STK-THKPavilion 42.7°Culet: LargeDepth 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: Oct 29
Current: £11,901 GBP|Low: £3,058 GBP|High: £26,235 GBP|Avg: £10,686 GBP|-4.0%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
Retailer 13
Retailer 14
Retailer 15
October 31, 2026
Retailer 12£3,058 GBP
Retailer 10£3,204 GBP
Retailer 15£4,634 GBP
Retailer 9£4,704 GBP
Retailer 2£4,892 GBP
Retailer 3£5,213 GBP
Retailer 14£6,334 GBP
Retailer 8£6,336 GBP
Retailer 13£6,774 GBP
Retailer 6£9,022 GBP
Retailer 11£9,737 GBP
MOH London£11,901 GBP
Retailer 4£17,016 GBP
Retailer 7£22,186 GBP
Retailer 5£26,235 GBP

32 data points across 15 retailers

10 retailers£3,058 GBP to £11,901 GBP

A
Cheapest Retailer
-
£3,058 GBP
$4,097 USD
A
Retailer 2
-
£3,204 GBP
$4,293 USD
View
A
Retailer 3
-
£4,634 GBP
$6,209 USD
View
Final sale: no returns
A
Retailer 4
-
£4,704 GBP
$6,303 USD
View
A
Retailer 5
-
£4,892 GBP
$6,555 USD
View
A
Retailer 6
-
£6,334 GBP
$8,487 USD
View
A
Retailer 7
-
£6,336 GBP
$8,490 USD
View
B+
Retailer 8
-
£6,774 GBP
€8,644 EUR
View
B+
Retailer 9
-
£9,737 GBP
$13,046 USD
View
Most Expensive
B+
MOH London
LG780662156 · Oct 29
£11,901 GBP
View
9 more retailers have this diamond
Prices start from £3,058 GBPSave up to £8,843 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
4.21ct Cushion
£3,058 GBP