Radiant|Lab Grown|IGI

1.78ct H SI2 Radiant Lab Grown Diamond

ID • H/SI2 • IGI LG512231558

Shape and cutting style on the report: Cut cornered rectangular modified brilliant

Certificate IGI LG512231558

Diamond specifications and retailer prices

From €931 EUR
As of November 6, 2026
Save €1,843 EUR (66%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: €4,234 EUR at MOH London · As of October 27, 2026
View at MOH London

About this 1.78ct lab-grown radiant diamond

This 1.78ct lab-grown radiant sits in the one-and-a-half to two carat band, graded H colour (near-colourless) and SI2 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG512231558 or 512231558. Listed at 9 retailers as of November 6, 2026, with a 198% spread between the cheapest and most expensive listing. That is exactly the kind of price-discovery gap Carat Hunter was built to surface. 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

1.78
Carat
H
Colour
SI2
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle43°
Pavilion angle29.7°
OriginLab Grown
Grading LabIGI
CertificateIGI LG512231558
Dimensions8.12 × 5.95 × 4.04 mm
L/W Ratio1.36
Culet sizePointed
Cert comments
This Laboratory Grown Diamond was created by Chemical Vapor Deposition (CVD) growth process and may include post-growth treatment Type IIa
Top View
8.12 mm5.95 mm1.78 ctH / SI2
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG512231558
Side View
Table 65.0%Crown 43°Girdle: ThickPavilion 29.7°Culet: 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: Nov 6
Current: €4,234 EUR|Low: €931 EUR|High: €4,285 EUR|Avg: €2,142 EUR|-0.9%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
October 30, 2026
Retailer 2€931 EUR
Retailer 3€1,276 EUR
Retailer 7€1,388 EUR
Retailer 4€1,481 EUR
Retailer 10€1,641 EUR
Retailer 9€2,026 EUR
Retailer 5€2,336 EUR
Retailer 8€2,687 EUR
Retailer 6€2,775 EUR
MOH London€4,234 EUR

14 data points across 10 retailers

9 retailers€931 EUR to €2,775 EUR

A
Cheapest Retailer
-
€931 EUR
A
Retailer 2
-
€1,276 EUR
View
A
Retailer 3
-
€1,388 EUR
View
Retailer 4
-
€1,481 EUR
View
Price last confirmed 26 days ago
B+
Retailer 5
-
€1,481 EUR
View
B
Retailer 6
-
€2,336 EUR
View
B
Retailer 7
-
€2,687 EUR
View
B
Retailer 8
-
€2,775 EUR
View
Most Expensive
MOH London
LG512231558 · Oct 27
€4,234 EUR
£3,722 GBP
View
Price last confirmed 11 days ago
8 more retailers have this diamond
Prices start from €931 EURSave up to €1,843 EUR

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 Radiant
€931 EUR