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Marquise|Lab Grown|IGI

0.51ct D SI1 Marquise Lab Grown Diamond

EX • D/SI1 • IGI LG817665899

Shape and cutting style on the report: Marquise brilliant

Certificate IGI LG817665899

Diamond specifications and retailer prices

From £118 GBP
$158 USD
As of November 1, 2026
Save £526 GBP (82%) vs most expensive(unlock to see where)
8 retailers carry this diamond
Most expensive: £644 GBP at MOH London · As of October 29, 2026
View at MOH London

About this 0.51ct lab-grown marquise diamond

This 0.51ct lab-grown marquise sits in the half to three-quarter carat band, graded D colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG817665899 or 817665899. Listed at 8 retailers as of October 29, 2026, with prices from £118 to £644, a £526 spread on the same certified stone. MOH London lists it at £644. 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

0.51
Carat
D
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryVery Good
FluorescenceNone
Crown angle37.5°
Pavilion angle41.2°
OriginLab Grown
Grading LabIGI
CertificateIGI LG817665899
Dimensions8.18 × 4.05 × 2.65 mm
L/W Ratio2.02
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
8.18 mm4.05 mm0.51 ctD / SI1
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryVery Good
FluorescenceNone
CertificateIGI LG817665899
Side View
Table 63.0%Crown 37.5°Girdle: MED-STKPavilion 41.2°Culet: NoneDepth 65.4%

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: Nov 1
Current: £644 GBP|Low: £93 GBP|High: £648 GBP|Avg: £247 GBP|+0.4%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
November 1, 2026
Retailer 5£93 GBP
Retailer 8£118 GBP
Retailer 6£138 GBP
Retailer 3£161 GBP
Retailer 2£165 GBP
Retailer 4£210 GBP
Retailer 7£284 GBP
MOH London£644 GBP

43 data points across 8 retailers

8 retailers£118 GBP to £644 GBP

Retailer 1
-
£93 GBP
$124 USD
Price last confirmed 7 days ago
A
Retailer 2
-
£118 GBP
$158 USD
View
A
Retailer 3
-
£138 GBP
$185 USD
View
A
Retailer 4
-
£161 GBP
€206 EUR
View
B+
Retailer 5
-
£165 GBP
View
B+
Retailer 6
-
£210 GBP
View
B
Retailer 7
-
£284 GBP
$380 USD
View
Most Expensive
B
MOH London
LG817665899 · Oct 29
£644 GBP
View
7 more retailers have this diamond
Prices start from £118 GBPSave up to £526 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
0.51ct Marquise
£118 GBP