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Cushion|Lab Grown|IGI

3.18ct D SI1 Cushion Lab Grown Diamond

EX • D/SI1 • IGI LG639415932

Shape and cutting style on the report: Square cushion brilliant

Certificate IGI LG639415932

Diamond specifications and retailer prices

From £437 GBP
$585 USD
As of October 31, 2026
Save £1,180 GBP (73%) vs most expensive(unlock to see where)
11 retailers carry this diamond
Most expensive: £1,617 GBP at MOH London · As of October 29, 2026
View at MOH London

About this 3.18ct lab-grown cushion diamond

This 3.18ct lab-grown cushion sits in the three to five carat band, graded D colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG639415932 or 639415932. Listed at 11 retailers as of October 29, 2026, with prices from £437 to £1,617, a £1,180 spread on the same certified stone. MOH London lists it at £1,617. 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

3.18
Carat
D
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34.6°
Pavilion angle39.6°
OriginLab Grown
Grading LabIGI
CertificateIGI LG639415932
Dimensions8.76 × 8.65 × 5.53 mm
L/W Ratio1.01
Girdle conditionFaceted
Culet sizePointed
Cert comments
This Laboratory Grown Diamond was created by Chemical Vapor Deposition (CVD) growth process Type IIa
Top View
8.76 mm8.65 mm3.18 ctD / SI1
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG639415932
Side View
Table 63.0%Crown 34.6°Girdle: MED-STKPavilion 39.6°Culet: NoneDepth 63.9%

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 31
Current: £1,617 GBP|Low: £437 GBP|High: £2,043 GBP|Avg: £835 GBP|-19.9%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
October 31, 2026
Retailer 3£437 GBP
Retailer 9£438 GBP
Retailer 8£478 GBP
Retailer 5£541 GBP
Retailer 6£571 GBP
Retailer 2£661 GBP
Retailer 7£663 GBP
Retailer 4£720 GBP
Retailer 10£1,255 GBP
Retailer 11£1,389 GBP
MOH London£1,617 GBP

44 data points across 11 retailers

11 retailers£437 GBP to £1,617 GBP

A
Cheapest Retailer
-
£437 GBP
$585 USD
Final sale: no returns
Retailer 2
-
£438 GBP
$587 USD
View
Price last confirmed 15 days ago
A
Retailer 3
-
£478 GBP
HK$5,000 HKD
View
A
Retailer 4
-
£541 GBP
$725 USD
View
B+
Retailer 5
-
£571 GBP
$765 USD
View
A
Retailer 6
-
£661 GBP
€843 EUR
View
A
Retailer 7
-
£663 GBP
$888 USD
View
A
Retailer 8
-
£720 GBP
View
B
Retailer 9
-
£1,255 GBP
$1,681 USD
View
B+
Retailer 10
-
£1,389 GBP
SGD 2,515 SGD
View
Most Expensive
B
MOH London
LG639415932 · Oct 29
£1,617 GBP
View
10 more retailers have this diamond
Prices start from £437 GBPSave up to £1,180 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
3.18ct Cushion
£437 GBP