CaratHunter
Plans
Round|Lab Grown|IGI

1.20ct D SI1 Round Lab Grown Diamond

EX • D/SI1 • IGI LG780664327

Shape and cutting style on the report: Round brilliant

Certificate IGI LG780664327

Diamond specifications and retailer prices

From £134 GBP
$179 USD
As of October 28, 2026
Save £551 GBP (80%) vs most expensive(unlock to see where)
10 retailers carry this diamond
Most expensive: £686 GBP at MOH London · As of October 29, 2026
View at MOH London

About this 1.2ct lab-grown round diamond

This 1.2ct lab-grown round sits in the classic one-carat band, graded D colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG780664327 or 780664327. Listed at 10 retailers as of October 28, 2026, with prices from £134 to £686, a £551 spread on the same certified stone. MOH London lists it at £686. 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

1.20
Carat
D
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle33.4°
Pavilion angle40.4°
OriginLab Grown
Grading LabIGI
CertificateIGI LG780664327
Dimensions6.93 × 6.88 × 4.09 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
6.93 mm6.88 mm1.20 ctD / SI1
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG780664327
Side View
Table 61.0%Crown 33.4°Girdle: MediumPavilion 40.4°Culet: NoneDepth 59.2%

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: Oct 28
Current: £686 GBP|Low: £96 GBP|High: £827 GBP|Avg: £411 GBP|-2.7%
MOH London
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
October 29, 2026
Retailer 9£134 GBP
Retailer 11£148 GBP
Retailer 10£259 GBP
Retailer 7£265 GBP
Retailer 2£286 GBP
Retailer 6£334 GBP
Retailer 12£390 GBP
Retailer 5£496 GBP
Retailer 3£522 GBP
Retailer 8£661 GBP
MOH London£686 GBP
Retailer 4£827 GBP

23 data points across 12 retailers

10 retailers£134 GBP to £686 GBP

Retailer 1
-
£120 GBP
$160 USD
Price last confirmed 37 days ago
A
Retailer 2
-
£134 GBP
$179 USD
View
Final sale: no returns
Retailer 3
-
£140 GBP
$186 USD
View
Price last confirmed 37 days ago
B+
Retailer 4
-
£265 GBP
$353 USD
View
B+
Retailer 5
-
£286 GBP
€363 EUR
View
B+
Retailer 6
-
£334 GBP
$445 USD
View
Retailer 7
-
£479 GBP
$638 USD
View
Price last confirmed 33 days ago
B
Retailer 8
-
£496 GBP
$660 USD
View
B
Retailer 9
-
£661 GBP
$880 USD
View
Most Expensive
B
MOH London
LG780664327 · Oct 29
£686 GBP
View
9 more retailers have this diamond
Prices start from £134 GBPSave up to £551 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
1.20ct Round
£134 GBP