Round|Natural|GIA

0.51ct K SI2 Round Natural Diamond

EX • K/SI2 • GIA 1403359121

Certificate GIA 1403359121

Diamond specifications and retailer prices

From $500 USD
As of November 4, 2026
Save $643 USD (56%) vs most expensive(unlock to see where)
12 retailers carry this diamond
Most expensive: $1,899 USD 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
Color
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: $523 USD|Low: $500 USD|High: $1,158 USD|Avg: $655 USD|-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$500 USD
Retailer 1$523 USD
Retailer 9$527 USD
Retailer 8$534 USD
Retailer 10$549 USD
Retailer 3$610 USD
Retailer 4$622 USD
Retailer 2$673 USD
Retailer 5$738 USD
Retailer 7$1,143 USD

39 data points across 10 retailers

12 retailers$500 USD to $1,143 USD

Retailer 1
-
$495 USD
Price last confirmed 44 days ago
Retailer 2
-
$495 USD
View
Price last confirmed 36 days ago
A
Retailer 3
-
$500 USD
View
A
Retailer 4
-
$523 USD
View
B+
Retailer 5
-
$527 USD
View
Retailer 6
-
$572 USD
View
Price last confirmed 44 days ago
B+
Retailer 7
-
$610 USD
View
B+
Retailer 8
-
$622 USD
View
B
Retailer 9
-
$673 USD
View
B
Retailer 10
-
$738 USD
View
B
Retailer 11
-
$1,143 USD
View
Most Expensive
NZ Jewellers
7b311409-20ed-4b64-85b2-5f0df2c37e1d · Sep 24
$1,899 USD
View
Price last confirmed 42 days ago
11 more retailers have this diamond
Prices start from $500 USDSave up to $643 USD

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
$500 USD