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Round|Natural|GIA

1.66ct M SI1 Round Natural Diamond

EX • M/SI1 • GIA 2547765261

Certificate GIA 2547765261

Diamond specifications and retailer prices

From £1,817 GBP
As of November 4, 2026
Save £2,352 GBP (56%) vs most expensive(unlock to see where)
13 retailers carry this diamond
Most expensive: £4,244 GBP at NZ Jewellers · As of October 23, 2026
View at NZ Jewellers

About this 1.66ct natural round diamond

This 1.66ct natural round sits in the one-and-a-half to two carat band, graded M colour (faint-tinted) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 2547765261. Listed at 13 retailers as of November 4, 2026, with a 129% 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

1.66
Carat
M
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceFaint
Crown angle36°
Pavilion angle41.2°
OriginNatural
Grading LabGIA
CertificateGIA 2547765261
Dimensions7.53 × 7.58 × 4.71 mm
L/W Ratio1.01
Top View
7.53 mm7.58 mm1.66 ctM / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceFaint
CertificateGIA 2547765261
Side View
Table 58.0%Crown 36°Girdle: MediumPavilion 41.2°Culet: NoneDepth 62.3%

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 4
Current: £4,169 GBP|Low: £1,788 GBP|High: £4,441 GBP|Avg: £2,754 GBP|-6.1%
NZ Jewellers
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
November 6, 2026
Retailer 11£1,817 GBP
Retailer 3£2,002 GBP
Retailer 8£2,208 GBP
Retailer 10£2,320 GBP
Retailer 4£2,451 GBP
Retailer 12£2,454 GBP
Retailer 2£2,605 GBP
Retailer 7£2,649 GBP
Retailer 5£2,780 GBP
Retailer 6£2,920 GBP
Retailer 9£3,745 GBP
NZ Jewellers£4,169 GBP

38 data points across 12 retailers

13 retailers£1,817 GBP to £4,169 GBP

A
Cheapest Retailer
-
£1,817 GBP
Retailer 2
-
£2,002 GBP
View
Price last confirmed 17 days ago
A
Retailer 3
-
£2,208 GBP
View
Final sale: no returns
B+
Retailer 4
-
£2,320 GBP
View
B+
Retailer 5
-
£2,451 GBP
View
B+
Retailer 6
-
£2,454 GBP
View
B+
Retailer 7
-
£2,605 GBP
View
B+
Retailer 8
-
£2,649 GBP
View
B+
Retailer 9
-
£2,780 GBP
View
B+
Retailer 10
-
£2,920 GBP
View
B
Retailer 11
-
£3,745 GBP
View
B
Retailer 12
-
£4,169 GBP
View
Most Expensive
NZ Jewellers
c3dc410e-7922-4c5e-aaf1-a752583d0752 · Oct 23
£4,244 GBP
$5,680 USD
View
Price last confirmed 14 days ago
12 more retailers have this diamond
Prices start from £1,817 GBPSave up to £2,352 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
1.66ct Round
£1,817 GBP