Round|Natural|GIA

1.51ct I SI2 Round Natural Diamond

ID • I/SI2 • GIA 225

Certificate GIA 225

Diamond specifications and retailer prices

From $3,557 AUD
As of October 31, 2026
Save $6,053 AUD (63%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: $9,610 AUD 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 $3,557 to $9,610, a $6,053 spread on the same certified stone. Blue Nile lists it at $9,610. 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: $9,610 AUD|Low: $3,557 AUD|High: $9,610 AUD|Avg: $6,946 AUD
Blue Nile
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
November 5, 2026
Retailer 6$3,557 AUD
Retailer 3$4,580 AUD
Retailer 4$4,755 AUD
Retailer 5$5,284 AUD
Retailer 7$7,501 AUD
Retailer 2$7,978 AUD
Blue Nile$9,610 AUD

12 data points across 7 retailers

9 retailers$3,557 AUD to $9,610 AUD

A
Cheapest Retailer
-
$3,557 AUD
A
Retailer 2
-
$4,580 AUD
View
A
Retailer 3
-
$4,755 AUD
View
A
Retailer 4
-
$5,284 AUD
View
B+
Retailer 5
-
$7,501 AUD
View
Retailer 6
-
$7,945 AUD
View
Price last confirmed 60 days ago
B+
Retailer 7
-
$7,978 AUD
View
B+
Retailer 8
-
$8,174 AUD
View
Most Expensive
B+
Blue Nile
29189376 · Nov 5
$9,610 AUD
$6,727 USD
View
8 more retailers have this diamond
Prices start from $3,557 AUDSave up to $6,053 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
1.51ct Round
$3,557 AUD