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Cushion|Lab Grown|IGI

1.78ct D FL Cushion Lab Grown Diamond

ID • D/FL • IGI LG846664592

Shape and cutting style on the report: Cushion modified brilliant

Certificate IGI LG846664592

Diamond specifications and retailer prices

From £503 GBP
As of October 30, 2026
Save £4,198 GBP (89%) vs most expensive(unlock to see where)
3 retailers carry this diamond
Most expensive: £4,702 GBP at Brilliant Earth · As of October 30, 2026
View at Brilliant Earth

About this 1.78ct lab-grown cushion diamond

This 1.78ct lab-grown cushion sits in the one-and-a-half to two carat band, graded D colour (colourless) and FL clarity (flawless or internally-flawless), with a top-tier cut grade and certified by IGI LG846664592 or 846664592. Listed at 3 retailers as of October 30, 2026, with prices from £503 to £4,702, a £4,198 spread on the same certified stone. Brilliant Earth lists it at £4,702. Compare the cross-retailer prices above before buying. The same certified stone often varies 15 to 40% across stores.

The 4Cs

1.78
Carat
D
Colour
FL
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle33.8°
Pavilion angle35.7°
OriginLab Grown
Grading LabIGI
CertificateIGI LG846664592
Dimensions8.63 × 6.22 × 4.30 mm
L/W Ratio1.39
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
8.63 mm6.22 mm1.78 ctD / FL
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG846664592
Side View
Table 57.0%Crown 33.8°Girdle: MED-STKPavilion 35.7°CuletDepth 69.1%

Caratlytics Score

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A
Excellent
Excellent quality and great value
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Price History

Last verified: Oct 30
Current: £4,702 GBP|Low: £503 GBP|High: £4,702 GBP|Avg: £2,792 GBP
Brilliant Earth
Retailer 2
Retailer 3
October 31, 2026
Retailer 3£503 GBP
Retailer 2£3,549 GBP
Brilliant Earth£4,702 GBP

2 data points across 3 retailers

3 retailers£503 GBP to £4,702 GBP

A
Cheapest Retailer
-
£503 GBP
B
Retailer 2
-
£3,549 GBP
$4,755 USD
View
Most Expensive
B
Brilliant Earth
22370033A · Oct 30
£4,702 GBP
$6,300 USD
View
2 more retailers have this diamond
Prices start from £503 GBPSave up to £4,198 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
1.78ct Cushion
£503 GBP