Round|Lab Grown|IGI

1.65ct F SI1 Round Lab Grown Diamond

EX • F/SI1 • IGI LG12378006

Shape and cutting style on the report: Round brilliant

Certificate IGI LG12378006

Diamond specifications and retailer prices

From £274 GBP
$368 USD
As of November 1, 2026
Save £1,048 GBP (79%) vs most expensive(unlock to see where)
20 retailers carry this diamond
Most expensive: £2,437 GBP at Do Amore Diamonds · As of November 2, 2026
View at Do Amore Diamonds

About this 1.65ct lab-grown round diamond

This 1.65ct lab-grown round sits in the one-and-a-half to two carat band, graded F colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG12378006 or 12378006. Listed at 20 retailers as of October 31, 2026, with a 382% 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

1.65
Carat
F
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34°
Pavilion angle41.1°
OriginLab Grown
Grading LabIGI
CertificateIGI LG12378006
Dimensions7.64 × 7.67 × 4.62 mm
L/W Ratio1.00
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
7.64 mm7.67 mm1.65 ctF / SI1
OriginLab Grown
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG12378006
Side View
Table 60.0%Crown 34°Girdle: MED-UNDPavilion 41.1°Culet: NoneDepth 60.3%

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 1
Current: £2,437 GBP|Low: £274 GBP|High: £2,437 GBP|Avg: £784 GBP
Do Amore Diamonds
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
Retailer 17
Retailer 18
Retailer 19
Retailer 20
November 2, 2026
Retailer 20£274 GBP
Retailer 3£313 GBP
Retailer 18£318 GBP
Retailer 5£341 GBP
Retailer 16£341 GBP
Retailer 15£349 GBP
Retailer 7£451 GBP
Retailer 8£563 GBP
Retailer 19£589 GBP
Retailer 13£616 GBP
Retailer 10£622 GBP
Retailer 12£669 GBP
Retailer 2£690 GBP
Retailer 6£998 GBP
Retailer 9£1,082 GBP
Retailer 14£1,162 GBP
Retailer 4£1,208 GBP
Retailer 11£1,322 GBP
Retailer 17£1,470 GBP
Do Amore Diamonds£2,437 GBP

17 data points across 20 retailers

20 retailers£274 GBP to £1,322 GBP

A
Cheapest Retailer
-
£274 GBP
$368 USD
A
Retailer 2
-
£313 GBP
$420 USD
View
A
Retailer 3
-
£318 GBP
$427 USD
View
Retailer 4
-
£341 GBP
$457 USD
View
Price last confirmed 8 days ago
A
Retailer 5
-
£341 GBP
$457 USD
View
B+
Retailer 6
-
£349 GBP
$468 USD
View
B+
Retailer 7
-
£451 GBP
$605 USD
View
Retailer 8
-
£563 GBP
$755 USD
View
Price last confirmed 12 days ago
B+
Retailer 9
-
£589 GBP
$791 USD
View
B
Retailer 10
-
£616 GBP
View
B
Retailer 11
-
£622 GBP
$835 USD
View
B+
Retailer 12
-
£669 GBP
$898 USD
View
B+
Retailer 13
-
£690 GBP
View
B
Retailer 14
-
£998 GBP
$1,339 USD
View
B
Retailer 15
-
£1,082 GBP
$1,452 USD
View
B
Retailer 16
-
£1,162 GBP
$1,560 USD
View
B
Retailer 17
-
£1,208 GBP
$1,621 USD
View
B
Retailer 18
-
£1,322 GBP
$1,775 USD
View
Retailer 19
-
£1,470 GBP
View
Price last confirmed 8 days ago
Most Expensive
Do Amore Diamonds
27-EC6B3E9CB · Nov 2
£2,437 GBP
$3,270 USD
View
Price under review
19 more retailers have this diamond
Prices start from £274 GBPSave up to £1,048 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
1.65ct Round
£274 GBP