Round|Natural|GIA

0.51ct I SI1 Round Natural Diamond

EX • I/SI1 • GIA 5556598199

Certificate GIA 5556598199

Diamond specifications and retailer prices

From £366 GBP
$490 USD
As of October 29, 2026
Save £1,138 GBP (76%) vs most expensive(unlock to see where)
19 retailers carry this diamond
Most expensive: £1,640 GBP at NZ Jewellers · As of October 17, 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 I colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 5556598199. Listed at 19 retailers as of October 29, 2026, with a 311% 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
I
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle36°
Pavilion angle40.8°
OriginNatural
Grading LabGIA
CertificateGIA 5556598199
Dimensions5.08 × 5.12 × 3.17 mm
L/W Ratio1.01
Culet sizeNone
Key to symbols
Crystal
Top View
5.08 mm5.12 mm0.51 ctI / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 5556598199
Side View
Table 59.0%Crown 36°Girdle: MED-STKPavilion 40.8°Culet: NoneDepth 62.2%

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: Oct 29
Current: £697 GBP|Low: £332 GBP|High: £1,222 GBP|Avg: £724 GBP|+3.5%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
November 1, 2026
Retailer 6£366 GBP
Retailer 3£612 GBP
Retailer 2£642 GBP
Retailer 1£697 GBP
Retailer 8£729 GBP
Retailer 7£786 GBP
Retailer 4£807 GBP
Retailer 5£1,214 GBP

41 data points across 8 retailers

19 retailers£366 GBP to £1,504 GBP

A
Cheapest Retailer
-
£366 GBP
$490 USD
Final sale: no returns
A
Retailer 2
-
£487 GBP
$652 USD
View
Retailer 3
-
£493 GBP
$660 USD
View
Price last confirmed 13 days ago
Retailer 4
-
£510 GBP
$683 USD
View
Price last confirmed 16 days ago
Retailer 5
-
£510 GBP
$683 USD
View
Price last confirmed 17 days ago
Retailer 6
-
£546 GBP
$732 USD
View
Price last confirmed 40 days ago
B+
Retailer 7
-
£556 GBP
$745 USD
View
B+
Retailer 8
-
£580 GBP
$777 USD
View
B+
Retailer 9
-
£612 GBP
$820 USD
View
B+
Retailer 10
-
£627 GBP
$840 USD
View
B
Retailer 11
-
£642 GBP
View
B
Retailer 12
-
£663 GBP
$888 USD
View
B+
Retailer 13
-
£697 GBP
€889 EUR
View
B+
Retailer 14
-
£729 GBP
$977 USD
View
Retailer 15
-
£786 GBP
A$1,621 AUD
View
Price last confirmed 27 days ago
B
Retailer 16
-
£807 GBP
ZAR 17,467 ZAR
View
Retailer 17
-
£1,214 GBP
View
Price last confirmed 11 days ago
B
Retailer 18
-
£1,504 GBP
CA$2,799 CAD
View
Most Expensive
NZ Jewellers
73cd0e3b-7c4d-4c16-b8db-b395cd03d181 · Oct 17
£1,640 GBP
$2,197 USD
View
Price last confirmed 15 days ago
18 more retailers have this diamond
Prices start from £366 GBPSave up to £1,138 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
£366 GBP