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Round|Lab Grown|IGI

3.51ct E SI1 Round Lab Grown Diamond

ID • E/SI1 • IGI LG670420051

Shape and cutting style on the report: Round brilliant

Certificate IGI LG670420051

Diamond specifications and retailer prices

From £284 GBP
$378 USD
As of October 29, 2026
Save £1,173 GBP (81%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: £1,457 GBP at Rare Carat · As of October 28, 2026
View at Rare Carat

About this 3.51ct lab-grown round diamond

This 3.51ct lab-grown round sits in the three to five carat band, graded E colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG670420051 or 670420051. Listed at 9 retailers as of October 28, 2026, with prices from £284 to £1,457, a £1,173 spread on the same certified stone. Rare Carat lists it at £1,457. 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

3.51
Carat
E
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle33.5°
Pavilion angle40.5°
OriginLab Grown
Grading LabIGI
CertificateIGI LG670420051
Dimensions9.88 × 9.85 × 5.89 mm
L/W Ratio1.00
Girdle conditionFaceted
Culet sizePointed
Cert comments
HEARTS & ARROWS This Laboratory Grown Diamond was created by Chemical Vapor Deposition (CVD) growth process Type IIa
Top View
9.88 mm9.85 mm3.51 ctE / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG670420051
Side View
Table 58.0%Crown 33.5°Girdle: MediumPavilion 40.5°Culet: NoneDepth 59.7%

Caratlytics Score

How it works →
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 29
Current: £1,457 GBP|Low: £284 GBP|High: £3,702 GBP|Avg: £1,178 GBP|-0.9%
Rare Carat
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
October 29, 2026
Retailer 11£284 GBP
Retailer 9£318 GBP
Retailer 2£565 GBP
Retailer 14£602 GBP
Retailer 6£830 GBP
Retailer 4£870 GBP
Retailer 3£926 GBP
Retailer 10£987 GBP
Retailer 8£987 GBP
Retailer 12£1,131 GBP
Retailer 7£1,376 GBP
Retailer 13£1,406 GBP
Rare Carat£1,457 GBP
Retailer 5£3,702 GBP

27 data points across 14 retailers

9 retailers£284 GBP to £1,457 GBP

A
Cheapest Retailer
-
£284 GBP
$378 USD
A
Retailer 2
-
£318 GBP
$423 USD
View
A
Retailer 3
-
£565 GBP
€716 EUR
View
B+
Retailer 4
-
£987 GBP
$1,314 USD
View
B+
Retailer 5
-
£987 GBP
$1,315 USD
View
B+
Retailer 6
-
£1,131 GBP
$1,506 USD
View
B+
Retailer 7
-
£1,376 GBP
View
Retailer 8
-
£1,406 GBP
SGD 2,530 SGD
View
Price last confirmed 17 days ago
Most Expensive
B
Rare Carat
LGRD30-86336 · Oct 28
£1,457 GBP
$1,940 USD
View
8 more retailers have this diamond
Prices start from £284 GBPSave up to £1,173 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
3.51ct Round
£284 GBP