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Round|Lab Grown|IGI

1.55ct D SI1 Round Lab Grown Diamond

ID • D/SI1 • IGI LG778645865

Shape and cutting style on the report: Round brilliant

Certificate IGI LG778645865

Diamond specifications and retailer prices

From £167 GBP
As of November 5, 2026
Save £1,044 GBP (86%) vs most expensive(unlock to see where)
19 retailers carry this diamond
Most expensive: £1,211 GBP at Brilliant Earth · As of November 5, 2026
View at Brilliant Earth

About this 1.55ct lab-grown round diamond

This 1.55ct lab-grown round sits in the one-and-a-half to two carat band, graded D colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI LG778645865 or 778645865. Listed at 19 retailers as of November 5, 2026, with prices from £167 to £1,211, a £1,044 spread on the same certified stone. Brilliant Earth lists it at £1,211. 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

1.55
Carat
D
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle35.4°
Pavilion angle40.5°
OriginLab Grown
Grading LabIGI
CertificateIGI LG778645865
Dimensions7.39 × 7.43 × 4.55 mm
L/W Ratio1.01
Girdle conditionFaceted
Culet sizePointed
Cert comments
As Grown - No indication of post-growth treatment This Laboratory Grown Diamond was created by High Pressure High Temperature (HPHT) growth process Type II
Top View
7.39 mm7.43 mm1.55 ctD / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG778645865
Side View
Table 58.0%Crown 35.4°Girdle: MED-STKPavilion 40.5°Culet: NoneDepth 61.5%

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 5
Current: £1,211 GBP|Low: £160 GBP|High: £1,211 GBP|Avg: £439 GBP
Brilliant Earth
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
Retailer 13
November 6, 2026
Retailer 10£167 GBP
Retailer 7£186 GBP
Retailer 3£194 GBP
Retailer 12£207 GBP
Retailer 11£279 GBP
Retailer 8£344 GBP
Retailer 6£380 GBP
Retailer 13£396 GBP
Retailer 5£605 GBP
Retailer 4£665 GBP
Retailer 2£667 GBP
Retailer 9£833 GBP
Brilliant Earth£1,211 GBP

43 data points across 13 retailers

19 retailers£167 GBP to £1,211 GBP

A
Cheapest Retailer
-
£167 GBP
A
Retailer 2
-
£186 GBP
View
Final sale: no returns
A
Retailer 3
-
£194 GBP
View
A
Retailer 4
-
£207 GBP
View
Retailer 5
-
£207 GBP
View
Price last confirmed 21 days ago
A
Retailer 6
-
£228 GBP
View
B+
Retailer 7
-
£279 GBP
View
A
Retailer 8
-
£344 GBP
View
A
Retailer 9
-
£346 GBP
View
A
Retailer 10
-
£380 GBP
View
B+
Retailer 11
-
£396 GBP
View
Retailer 12
-
£605 GBP
View
Price last confirmed 58 days ago
B
Retailer 13
-
£665 GBP
View
B
Retailer 14
-
£667 GBP
View
B
Retailer 15
-
£669 GBP
View
B
Retailer 16
-
£704 GBP
View
Retailer 17
-
£833 GBP
View
Price last confirmed 8 days ago
B
Retailer 18
-
£945 GBP
View
Most Expensive
B
Brilliant Earth
18623571A · Nov 5
£1,211 GBP
$1,630 USD
View
18 more retailers have this diamond
Prices start from £167 GBPSave up to £1,044 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
1.55ct Round
£167 GBP