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3.78ct F SI1 Round Lab Grown Diamond

ID • F/SI1 • IGI LG620425009

Shape and cutting style on the report: Round brilliant

Certificate IGI LG620425009

Diamond specifications and retailer prices

From £1,005 GBP
CA$1,873 CAD
As of November 2, 2026
Save £324 GBP (24%) vs most expensive(unlock to see where)
2 retailers carry this diamond
Most expensive: £1,329 GBP at The Diamond Guys · As of November 1, 2026
View at The Diamond Guys

About this 3.78ct lab-grown round diamond

This 3.78ct lab-grown round sits in the three to five carat band, graded F colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG620425009 or 620425009. Listed at 2 retailers as of November 1, 2026, with prices from £1,005 to £1,329, a £324 spread on the same certified stone. The Diamond Guys lists it at £1,329. 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

3.78
Carat
F
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34.1°
Pavilion angle40.8°
OriginLab Grown
Grading LabIGI
CertificateIGI LG620425009
Dimensions10.14 × 10.09 × 6.10 mm
L/W Ratio1.00
Girdle conditionFaceted
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
10.14 mm10.09 mm3.78 ctF / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG620425009
Side View
Table 58.0%Crown 34.1°Girdle: MediumPavilion 40.8°Culet: NoneDepth 60.3%

Caratlytics Score

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B+
Very Good
Strong quality and value balance
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Price History

Last verified: Nov 2
Current: £831 GBP|Low: £200 GBP|High: £2,422 GBP|Avg: £882 GBP|-8.4%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
The Diamond Guys
August 3, 2026
Retailer 2£544 GBP
Retailer 4£591 GBP
Retailer 7£662 GBP
Retailer 9£671 GBP
Retailer 6£778 GBP
Retailer 3£805 GBP
Retailer 1£831 GBP
Retailer 5£1,005 GBP
Retailer 10£1,304 GBP
The Diamond Guys£1,329 GBP
Retailer 8£2,072 GBP

59 data points across 11 retailers

2 retailers£1,005 GBP to £1,329 GBP

B+
Cheapest Retailer
-
£1,005 GBP
CA$1,873 CAD
Most Expensive
B
The Diamond Guys
1954434357 · Nov 1
£1,329 GBP
$1,784 USD
View
1 more retailer has this diamond
Prices start from £1,005 GBPSave up to £324 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.

B+
3.78ct Round
£1,005 GBP