Round|Natural|GIA

1.23ct E SI1 Round Natural Diamond

EX • E/SI1 • GIA 1565135099

Certificate GIA 1565135099

Diamond specifications and retailer prices

From £2,875 GBP
As of November 5, 2026
Save £482 GBP (14%) vs most expensive(unlock to see where)
9 retailers carry this diamond
Most expensive: £5,188 GBP at NZ Jewellers · As of October 27, 2026
View at NZ Jewellers

About this 1.23ct natural round diamond

This 1.23ct natural round sits in the classic one-carat band, graded E colour (colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 1565135099. Listed at 9 retailers as of October 30, 2026, with a relatively tight 17% spread, which is unusual at this carat range and suggests competitive pricing across the listings. 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

1.23
Carat
E
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceMedium
Crown angle36°
Pavilion angle41°
OriginNatural
Grading LabGIA
CertificateGIA 1565135099
Dimensions6.78 × 6.83 × 4.24 mm
L/W Ratio1.01
Girdle conditionSlightly Thick
Key to symbols
Crystal, Feather
Top View
6.78 mm6.83 mm1.23 ctE / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceMedium
CertificateGIA 1565135099
Side View
Table 59.0%Crown 36°GirdlePavilion 41°CuletDepth 62.3%

Caratlytics Score

How it works →
B+
Very Good
Strong quality and value balance
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See the detailed 0 to 100 score with Quality, Value, Certification & Market breakdown

Price History

Last verified: Nov 5
Current: £5,188 GBP|Low: £2,838 GBP|High: £5,213 GBP|Avg: £3,526 GBP|-0.5%
NZ Jewellers
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
October 30, 2026
Retailer 4£2,838 GBP
Retailer 9£2,875 GBP
Retailer 3£2,881 GBP
Retailer 6£2,978 GBP
Retailer 7£2,978 GBP
Retailer 8£3,193 GBP
Retailer 2£3,358 GBP
Retailer 5£4,985 GBP
NZ Jewellers£5,188 GBP

28 data points across 9 retailers

9 retailers£2,875 GBP to £3,358 GBP

Retailer 1
-
£2,838 GBP
Price last confirmed 9 days ago
B+
Retailer 2
-
£2,875 GBP
View
Retailer 3
-
£2,881 GBP
View
Price last confirmed 9 days ago
Retailer 4
-
£2,978 GBP
View
Price last confirmed 11 days ago
Retailer 5
-
£2,978 GBP
View
Price last confirmed 12 days ago
Retailer 6
-
£3,193 GBP
View
Price last confirmed 33 days ago
B+
Retailer 7
-
£3,358 GBP
View
Retailer 8
-
£4,985 GBP
View
Price last confirmed 11 days ago
Most Expensive
NZ Jewellers
f2159c02-59d5-4fbc-86aa-12c7fd592421 · Oct 27
£5,188 GBP
$6,982 USD
View
Price last confirmed 10 days ago
8 more retailers have this diamond
Prices start from £2,875 GBPSave up to £482 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.

B+
1.23ct Round
£2,875 GBP