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Round|Natural|GIA

1.00ct K SI1 Round Natural Diamond

EX • K/SI1 • GIA 2558715221

Certificate GIA 2558715221

Diamond specifications and retailer prices

From £1,141 GBP
As of November 6, 2026
Save £1,522 GBP (57%) vs most expensive(unlock to see where)
20 retailers carry this diamond
Most expensive: £3,187 GBP at NZ Jewellers · As of October 3, 2026
View at NZ Jewellers

About this 1ct natural round diamond

This 1ct natural round sits in the classic one-carat band, graded K colour (faint-tinted) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 2558715221. Listed at 20 retailers as of November 4, 2026, with a 133% 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

1.00
Carat
K
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle33.5°
Pavilion angle41.8°
OriginNatural
Grading LabGIA
CertificateGIA 2558715221
Dimensions6.40 × 6.46 × 3.93 mm
L/W Ratio1.01
Girdle conditionFaceted
Culet sizeNone
Key to symbols
Crystal, Cloud, Feather
Top View
6.40 mm6.46 mm1.00 ctK / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 2558715221
Side View
Table 61.0%Crown 33.5°Girdle: MED-STKPavilion 41.8°Culet: NoneDepth 61.1%

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 6
Current: £1,190 GBP|Low: £1,141 GBP|High: £2,703 GBP|Avg: £1,737 GBP|-3.1%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
November 6, 2026
Retailer 7£1,141 GBP
Retailer 1£1,190 GBP
Retailer 5£1,405 GBP
Retailer 8£1,458 GBP
Retailer 2£1,646 GBP
Retailer 4£1,860 GBP
Retailer 3£2,066 GBP
Retailer 6£2,664 GBP

35 data points across 8 retailers

20 retailers£1,141 GBP to £2,664 GBP

A
Cheapest Retailer
-
£1,141 GBP
A
Retailer 2
-
£1,190 GBP
View
B+
Retailer 3
-
£1,405 GBP
View
B+
Retailer 4
-
£1,427 GBP
View
B+
Retailer 5
-
£1,430 GBP
View
B+
Retailer 6
-
£1,458 GBP
View
B+
Retailer 7
-
£1,523 GBP
View
Retailer 8
-
£1,525 GBP
View
Price last confirmed 39 days ago
Retailer 9
-
£1,525 GBP
View
Price last confirmed 28 days ago
Retailer 10
-
£1,525 GBP
View
Price last confirmed 25 days ago
B+
Retailer 11
-
£1,589 GBP
View
Retailer 12
-
£1,595 GBP
View
Price last confirmed 38 days ago
B+
Retailer 13
-
£1,627 GBP
View
B+
Retailer 14
-
£1,646 GBP
View
Retailer 15
-
£1,759 GBP
View
Price last confirmed 38 days ago
B+
Retailer 16
-
£1,860 GBP
View
B
Retailer 17
-
£2,066 GBP
View
B
Retailer 18
-
£2,664 GBP
View
Retailer 19
-
£3,187 GBP
View
Price last confirmed 39 days ago
Most Expensive
NZ Jewellers
7368ce97-3a06-415c-8add-e03809881242 · Oct 3
£3,187 GBP
$4,290 USD
View
Price last confirmed 34 days ago
19 more retailers have this diamond
Prices start from £1,141 GBPSave up to £1,522 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
1.00ct Round
£1,141 GBP