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Round|Natural|GIA

0.51ct K SI2 Round Natural Diamond

EX • K/SI2 • GIA 1403359121

Certificate GIA 1403359121

Diamond specifications and retailer prices

From £371 GBP
As of November 4, 2026
Save £478 GBP (56%) vs most expensive(unlock to see where)
12 retailers carry this diamond
Most expensive: £1,411 GBP at NZ Jewellers · As of September 24, 2026
View at NZ Jewellers

About this 0.51ct natural round diamond

This 0.51ct natural round sits in the half to three-quarter carat band, graded K colour (faint-tinted) and SI2 clarity (slightly-included), with a top-tier cut grade and certified by GIA 1403359121. Listed at 12 retailers as of November 4, 2026, with a 129% 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

0.51
Carat
K
Colour
SI2
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceStrong
Crown angle36°
Pavilion angle40.8°
OriginNatural
Grading LabGIA
CertificateGIA 1403359121
Dimensions5.09 × 5.06 × 3.21 mm
L/W Ratio1.01
Star length50%
Lower girdle80%
Top View
5.09 mm5.06 mm0.51 ctK / SI2
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceStrong
CertificateGIA 1403359121
Side View
Table 55.0%Crown 36°Girdle: THN-THKPavilion 40.8°Culet: NoneDepth 63.2%

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 4
Current: £389 GBP|Low: £371 GBP|High: £860 GBP|Avg: £487 GBP|-1.3%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
November 6, 2026
Retailer 6£371 GBP
Retailer 1£389 GBP
Retailer 9£392 GBP
Retailer 8£397 GBP
Retailer 10£408 GBP
Retailer 3£453 GBP
Retailer 4£462 GBP
Retailer 2£500 GBP
Retailer 5£548 GBP
Retailer 7£849 GBP

39 data points across 10 retailers

12 retailers£371 GBP to £849 GBP

Retailer 1
-
£368 GBP
Price last confirmed 44 days ago
Retailer 2
-
£368 GBP
View
Price last confirmed 36 days ago
A
Retailer 3
-
£371 GBP
View
A
Retailer 4
-
£389 GBP
View
B+
Retailer 5
-
£392 GBP
View
Retailer 6
-
£425 GBP
View
Price last confirmed 44 days ago
B+
Retailer 7
-
£453 GBP
View
B+
Retailer 8
-
£462 GBP
View
B
Retailer 9
-
£500 GBP
View
B
Retailer 10
-
£548 GBP
View
B
Retailer 11
-
£849 GBP
View
Most Expensive
NZ Jewellers
7b311409-20ed-4b64-85b2-5f0df2c37e1d · Sep 24
£1,411 GBP
$1,899 USD
View
Price last confirmed 43 days ago
11 more retailers have this diamond
Prices start from £371 GBPSave up to £478 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
0.51ct Round
£371 GBP