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Cushion|Lab Grown|IGI

1.50ct D SI1 Cushion Lab Grown Diamond

ID • D/SI1 • IGI LG678551060

Shape and cutting style on the report: Square cushion modified brilliant

Certificate IGI LG678551060

Diamond specifications and retailer prices

From £156 GBP
$209 USD
As of October 30, 2026
Save £687 GBP (82%) vs most expensive(unlock to see where)
7 retailers carry this diamond
Most expensive: £843 GBP at Brilliant Earth · As of October 30, 2026
View at Brilliant Earth

About this 1.5ct lab-grown cushion diamond

This 1.5ct lab-grown cushion sits in the one-and-a-half to two carat band, graded D colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG678551060 or 678551060. Listed at 7 retailers as of October 30, 2026, with prices from £156 to £843, a £687 spread on the same certified stone. Brilliant Earth lists it at £843. 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

1.50
Carat
D
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34°
Pavilion angle36.9°
OriginLab Grown
Grading LabIGI
CertificateIGI LG678551060
Dimensions6.66 × 6.55 × 4.12 mm
L/W Ratio1.02
Girdle conditionFaceted
Culet sizePointed
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
6.66 mm6.55 mm1.50 ctD / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG678551060
Side View
Table 61.0%Crown 34°Girdle: STK-VTKPavilion 36.9°Culet: NoneDepth 62.9%

Caratlytics Score

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A
Excellent
Excellent quality and great value
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See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Oct 30
Current: £843 GBP|Low: £113 GBP|High: £985 GBP|Avg: £497 GBP|-14.4%
Brilliant Earth
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
October 30, 2026
Retailer 8£156 GBP
Retailer 5£290 GBP
Retailer 9£307 GBP
Retailer 2£314 GBP
Retailer 7£357 GBP
Retailer 6£430 GBP
Retailer 10£487 GBP
Retailer 11£585 GBP
Retailer 4£769 GBP
Brilliant Earth£843 GBP
Retailer 3£880 GBP

25 data points across 11 retailers

7 retailers£156 GBP to £843 GBP

A
Cheapest Retailer
-
£156 GBP
$209 USD
Final sale: no returns
B+
Retailer 2
-
£290 GBP
$388 USD
View
A
Retailer 3
-
£314 GBP
€401 EUR
View
A
Retailer 4
-
£357 GBP
$479 USD
View
B+
Retailer 5
-
£430 GBP
$576 USD
View
B
Retailer 6
-
£769 GBP
View
Most Expensive
B
Brilliant Earth
15325425A · Oct 30
£843 GBP
$1,130 USD
View
6 more retailers have this diamond
Prices start from £156 GBPSave up to £687 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
1.50ct Cushion
£156 GBP