Round|Lab Grown|IGI

1.78ct E SI1 Round Lab Grown Diamond

ID • E/SI1

Diamond specifications and retailer prices

From £167 GBP
$222 USD
As of October 29, 2026
Save £496 GBP (75%) vs most expensive(unlock to see where)
5 retailers carry this diamond
Most expensive: £663 GBP at NZ Jewellers · As of October 27, 2026
View at NZ Jewellers

About this 1.78ct lab-grown round diamond

This 1.78ct lab-grown round sits in the one-and-a-half to two carat band, graded E colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by IGI. Listed at 5 retailers as of October 27, 2026, with prices from £167 to £663, a £496 spread on the same certified stone. NZ Jewellers lists it at £663. 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

1.78
Carat
E
Colour
SI1
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
OriginLab Grown
Grading LabIGI
Dimensions7.78 × 7.82 × 0.00 mm
L/W Ratio1.01
Top View
7.78 mm7.82 mm1.78 ctE / SI1
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI
Side View
Table 58.0%CrownGirdle: MediumPavilionCulet: NoneDepth 61.1%

Caratlytics Score

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A
Excellent
Excellent quality and great value
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Price History

Last verified: Oct 29
Current: £663 GBP|Low: £164 GBP|High: £679 GBP|Avg: £347 GBP|-2.3%
NZ Jewellers
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
October 29, 2026
Retailer 4£167 GBP
Retailer 5£193 GBP
Retailer 3£207 GBP
Retailer 6£211 GBP
Retailer 2£358 GBP
Retailer 7£561 GBP
NZ Jewellers£663 GBP

30 data points across 7 retailers

5 retailers£167 GBP to £663 GBP

A
Cheapest Retailer
-
£167 GBP
$222 USD
A
Retailer 2
-
£193 GBP
$257 USD
View
A
Retailer 3
-
£207 GBP
$275 USD
View
A
Retailer 4
-
£358 GBP
View
Most Expensive
B
NZ Jewellers
cbee3b9f-6ee5-45a5-af39-b2f03e4aede7 · Oct 27
£663 GBP
$883 USD
View
4 more retailers have this diamond
Prices start from £167 GBPSave up to £496 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
1.78ct Round
£167 GBP