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Round|Natural|GIA

1.51ct I SI2 Round Natural Diamond

ID • I/SI2 • GIA 225

Certificate GIA 225

Diamond specifications and retailer prices

From £1,850 GBP
As of October 31, 2026
Save £3,148 GBP (63%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: £4,998 GBP at Blue Nile · As of November 5, 2026
View at Blue Nile

About this 1.51ct natural round diamond

This 1.51ct natural round sits in the one-and-a-half to two carat band, graded I colour (near-colourless) and SI2 clarity (slightly-included), with a top-tier cut grade and certified by GIA. Listed at 9 retailers as of October 31, 2026, with prices from £1,850 to £4,998, a £3,148 spread on the same certified stone. Blue Nile lists it at £4,998. 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

1.51
Carat
I
Colour
SI2
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
OriginNatural
Grading LabGIA
CertificateGIA 225
Dimensions7.27 × 7.32 × 4.58 mm
L/W Ratio1.01
Top View
7.27 mm7.32 mm1.51 ctI / SI2
OriginNatural
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 225
Side View
Table 56.0%CrownGirdle: MED-STKPavilionCulet: NoneDepth 62.7%

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: Oct 31
Current: £4,998 GBP|Low: £1,850 GBP|High: £4,998 GBP|Avg: £3,613 GBP
Blue Nile
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
November 5, 2026
Retailer 6£1,850 GBP
Retailer 3£2,382 GBP
Retailer 4£2,473 GBP
Retailer 5£2,748 GBP
Retailer 7£3,901 GBP
Retailer 2£4,150 GBP
Blue Nile£4,998 GBP

12 data points across 7 retailers

9 retailers£1,850 GBP to £4,998 GBP

A
Cheapest Retailer
-
£1,850 GBP
A
Retailer 2
-
£2,382 GBP
View
A
Retailer 3
-
£2,473 GBP
View
A
Retailer 4
-
£2,748 GBP
View
B+
Retailer 5
-
£3,901 GBP
View
Retailer 6
-
£4,133 GBP
View
Price last confirmed 60 days ago
B+
Retailer 7
-
£4,150 GBP
View
B+
Retailer 8
-
£4,251 GBP
View
Most Expensive
B+
Blue Nile
29189376 · Nov 5
£4,998 GBP
$6,727 USD
View
8 more retailers have this diamond
Prices start from £1,850 GBPSave up to £3,148 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
1.51ct Round
£1,850 GBP