Radiant|Natural|GIA

2.51ct I SI1 Radiant Natural Diamond

EX • I/SI1 • GIA 1518171703

Certificate GIA 1518171703

Diamond specifications and retailer prices

From $12,120 USD
As of November 2, 2026
Save $5,299 USD (30%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: $19,277 USD at NZ Jewellers · As of September 27, 2026
View at NZ Jewellers

About this 2.51ct natural radiant diamond

This 2.51ct natural radiant sits in the two to three carat band, graded I colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade stated by the retailer rather than the lab and certified by GIA 1518171703. Listed at 9 retailers as of November 1, 2026, with a 44% 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

2.51
Carat
I
Color
SI1
Clarity
Excellent
Cut (retailer stated)

Specifications

Cut (retailer stated)Excellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle44.73°
Pavilion angle31.36°
OriginNatural
Grading LabGIA
CertificateGIA 1518171703
Dimensions8.69 × 6.69 × 4.60 mm
L/W Ratio1.30
Girdle conditionVery Thick
Key to symbols
Feather, Cavity, Needle
Top View
8.69 mm6.69 mm2.51 ctI / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 1518171703
Side View
Table 66.0%Crown 44.73°GirdlePavilion 31.36°CuletDepth 68.7%

Caratlytics Score

How it works →
A
Excellent
Excellent quality and great value
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See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Nov 2
Current: $12,832 USD|Low: $12,120 USD|High: $18,282 USD|Avg: $13,915 USD|-4.7%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
November 2, 2026
Retailer 3$12,120 USD
Retailer 4$12,127 USD
Retailer 1$12,832 USD
Retailer 7$13,032 USD
Retailer 6$13,552 USD
Retailer 5$14,265 USD
Retailer 2$17,419 USD

37 data points across 7 retailers

9 retailers$12,120 USD to $17,419 USD

A
Cheapest Retailer
-
$12,120 USD
Retailer 2
-
$12,127 USD
A$18,657 AUD
View
Price last confirmed 9 days ago
A
Retailer 3
-
$12,832 USD
£10,104 GBP
View
Retailer 4
-
$13,618 USD
View
Price last confirmed 32 days ago
Retailer 5
-
$13,831 USD
View
Price last confirmed 37 days ago
Retailer 6
-
$13,831 USD
View
Price last confirmed 26 days ago
A
Retailer 7
-
$17,419 USD
£13,716 GBP
View
Retailer 8
-
$19,277 USD
View
Price last confirmed 26 days ago
Most Expensive
NZ Jewellers
4d56b567-6ce3-4faf-84e9-24a3f1d341c9 · Sep 27
$19,277 USD
View
Price last confirmed 36 days ago
8 more retailers have this diamond
Prices start from $12,120 USDSave up to $5,299 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
2.51ct Radiant
$12,120 USD