Cushion|Lab Grown|IGI

4.20ct D FL Cushion Lab Grown Diamond

EX • D/FL

Diamond specifications and retailer prices

From £3,960 GBP
$5,306 USD
As of October 31, 2026
Save £6,070 GBP (61%) vs most expensive(unlock to see where)
4 retailers carry this diamond
Most expensive: £19,248 GBP at Helzberg Diamonds · As of September 27, 2026
View at Helzberg Diamonds

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. Listed at 4 retailers as of October 31, 2026, with a 153% spread between the cheapest and most expensive listing. That is exactly the kind of price-discovery gap Carat Hunter was built to surface. 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
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
OriginLab Grown
Grading LabIGI
Dimensions9.40 × 9.21 × 6.25 mm
L/W Ratio1.02
Top View
9.40 mm9.21 mm4.20 ctD / FL
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI
Side View
Table 61.0%CrownGirdle: MED-STKPavilionCulet: NoneDepth 67.9%

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 31
Current: £19,248 GBP|Low: £4,070 GBP|High: £19,248 GBP|Avg: £10,371 GBP
Helzberg Diamonds
Retailer 2
Retailer 3
Retailer 4
October 23, 2026
Retailer 3£4,070 GBP
Retailer 2£4,400 GBP
Retailer 4£10,030 GBP
Helzberg Diamonds£19,248 GBP

6 data points across 4 retailers

4 retailers£3,960 GBP to £10,030 GBP

A
Cheapest Retailer
-
£3,960 GBP
$5,306 USD
A
Retailer 2
-
£4,070 GBP
$5,453 USD
View
B+
Retailer 3
-
£10,030 GBP
$13,439 USD
View
Most Expensive
Helzberg Diamonds
ZXZOGJMIJLMH · Sep 27
£19,248 GBP
$25,790 USD
View
Price last confirmed 34 days ago
3 more retailers have this diamond
Prices start from £3,960 GBPSave up to £6,070 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
£3,960 GBP