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Round|Natural|GIA

0.66ct M SI2 Round Natural Diamond

EX • M/SI2 • GIA 5503478758

Certificate GIA 5503478758

Diamond specifications and retailer prices

From £450 GBP
As of November 6, 2026
Save £86 GBP (16%) vs most expensive(unlock to see where)
7 retailers carry this diamond
Most expensive: £1,421 GBP at NZ Jewellers · As of September 24, 2026
View at NZ Jewellers

About this 0.66ct natural round diamond

This 0.66ct natural round sits in the half to three-quarter carat band, graded M colour (faint-tinted) and SI2 clarity (slightly-included), with a top-tier cut grade and certified by GIA 5503478758. Listed at 7 retailers as of November 5, 2026, with a relatively tight 19% 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

0.66
Carat
M
Colour
SI2
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle36°
Pavilion angle40.8°
OriginNatural
Grading LabGIA
CertificateGIA 5503478758
Dimensions5.51 × 5.53 × 3.46 mm
L/W Ratio1.00
Star length50%
Lower girdle75%
Top View
5.51 mm5.53 mm0.66 ctM / SI2
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 5503478758
Side View
Table 58.0%Crown 36°GirdlePavilion 40.8°Culet: NoneDepth 62.7%

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 6
Current: £450 GBP|Low: £450 GBP|High: £554 GBP|Avg: £520 GBP|-4.7%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
November 6, 2026
Retailer 1£450 GBP
Retailer 4£519 GBP
Retailer 2£536 GBP
Retailer 3£539 GBP

36 data points across 4 retailers

7 retailers£450 GBP to £536 GBP

Retailer 1
-
£371 GBP
Price last confirmed 29 days ago
Retailer 2
-
£399 GBP
View
Price last confirmed 29 days ago
Retailer 3
-
£399 GBP
View
Price last confirmed 38 days ago
Retailer 4
-
£428 GBP
View
Price last confirmed 38 days ago
B+
Retailer 5
-
£450 GBP
View
B
Retailer 6
-
£536 GBP
View
Most Expensive
NZ Jewellers
15ff43c4-a07b-4042-be2b-1ac38cb2d21b · Sep 24
£1,421 GBP
$1,912 USD
View
Price under review
6 more retailers have this diamond
Prices start from £450 GBPSave up to £86 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+
0.66ct Round
£450 GBP