Radiant|Lab Grown|IGI

12.78ct F SI1 Radiant Lab Grown Diamond

ID • F/SI1 • IGI LG591336712

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

Certificate IGI LG591336712

Diamond specifications and retailer prices

From €1,363 EUR
£1,199 GBP
As of November 2, 2026
Save €1,818 EUR (57%) vs most expensive(unlock to see where)
13 retailers carry this diamond
Most expensive: €9,796 EUR at Adiamor · As of November 2, 2026
View at Adiamor

About this 12.78ct lab-grown radiant diamond

This 12.78ct lab-grown radiant sits in the over five carat band, graded F colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG591336712 or 591336712. Listed at 13 retailers as of November 1, 2026, with a 133% 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

12.78
Carat
F
Color
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle44.8°
Pavilion angle34°
OriginLab Grown
Grading LabIGI
CertificateIGI LG591336712
Dimensions16.82 × 11.37 × 7.51 mm
L/W Ratio1.48
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
16.82 mm11.37 mm12.78 ctF / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG591336712
Side View
Table 65.0%Crown 44.8°Girdle: Slightly ThickPavilion 34°Culet: NoneDepth 66.1%

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 2
Current: €9,796 EUR|Low: €1,363 EUR|High: €20,483 EUR|Avg: €5,675 EUR|-52.2%
Adiamor
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
Retailer 13
Retailer 14
Retailer 15
Retailer 16
November 2, 2026
Retailer 2€1,363 EUR
Retailer 6€1,463 EUR
Retailer 5€1,592 EUR
Retailer 13€1,697 EUR
Retailer 14€1,848 EUR
Retailer 16€1,994 EUR
Retailer 15€2,237 EUR
Retailer 9€2,385 EUR
Retailer 10€2,669 EUR
Retailer 11€2,695 EUR
Retailer 12€2,926 EUR
Retailer 3€3,181 EUR
Retailer 4€5,447 EUR
Adiamor€9,796 EUR
Retailer 7€18,350 EUR
Retailer 8€18,394 EUR

7 data points across 16 retailers

13 retailers€1,363 EUR to €3,181 EUR

A
Cheapest Retailer
-
€1,363 EUR
£1,199 GBP
A
Retailer 2
-
€1,463 EUR
$1,635 USD
View
A
Retailer 3
-
€1,592 EUR
$1,779 USD
View
A
Retailer 4
-
€1,697 EUR
$1,896 USD
View
A
Retailer 5
-
€1,848 EUR
$2,065 USD
View
B+
Retailer 6
-
€1,994 EUR
HK$17,400 HKD
View
B+
Retailer 7
-
€2,237 EUR
$2,499 USD
View
B+
Retailer 8
-
€2,385 EUR
£2,098 GBP
View
B+
Retailer 9
-
€2,669 EUR
$2,982 USD
View
B
Retailer 10
-
€2,695 EUR
View
B+
Retailer 11
-
€2,926 EUR
$3,269 USD
View
B
Retailer 12
-
€3,181 EUR
$3,554 USD
View
Most Expensive
Adiamor
D-82832577 · Nov 2
€9,796 EUR
$10,944 USD
View
Price under review
12 more retailers have this diamond
Prices start from €1,363 EURSave up to €1,818 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
12.78ct Radiant
€1,363 EUR