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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 $714 AUD
As of November 4, 2026
Save $919 AUD (56%) vs most expensive(unlock to see where)
12 retailers carry this diamond
Most expensive: $2,713 AUD 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: $747 AUD|Low: $714 AUD|High: $1,654 AUD|Avg: $936 AUD|-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$714 AUD
Retailer 1$747 AUD
Retailer 9$753 AUD
Retailer 8$763 AUD
Retailer 10$784 AUD
Retailer 3$871 AUD
Retailer 4$889 AUD
Retailer 2$961 AUD
Retailer 5$1,054 AUD
Retailer 7$1,633 AUD

39 data points across 10 retailers

12 retailers$714 AUD to $1,633 AUD

Retailer 1
-
$707 AUD
Price last confirmed 44 days ago
Retailer 2
-
$707 AUD
View
Price last confirmed 36 days ago
A
Retailer 3
-
$714 AUD
View
A
Retailer 4
-
$747 AUD
View
B+
Retailer 5
-
$753 AUD
View
Retailer 6
-
$817 AUD
View
Price last confirmed 44 days ago
B+
Retailer 7
-
$871 AUD
View
B+
Retailer 8
-
$889 AUD
View
B
Retailer 9
-
$961 AUD
View
B
Retailer 10
-
$1,054 AUD
View
B
Retailer 11
-
$1,633 AUD
View
Most Expensive
NZ Jewellers
7b311409-20ed-4b64-85b2-5f0df2c37e1d · Sep 24
$2,713 AUD
$1,899 USD
View
Price last confirmed 43 days ago
11 more retailers have this diamond
Prices start from $714 AUDSave up to $919 AUD

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
$714 AUD