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Round|Natural|GIA

1.28ct I SI1 Round Natural Diamond

EX • I/SI1 • GIA 6515401647

Certificate GIA 6515401647

Diamond specifications and retailer prices

From £2,462 GBP
As of November 5, 2026
Save £1,204 GBP (33%) vs most expensive(unlock to see where)
5 retailers carry this diamond
Most expensive: £3,666 GBP at 77 Diamonds · As of November 6, 2026
View at 77 Diamonds

About this 1.28ct natural round diamond

This 1.28ct natural round sits in the one-and-a-quarter to one-and-a-half carat band, graded I colour (near-colourless) and SI1 clarity (slightly-included), with a top-tier cut grade and certified by GIA 6515401647. Listed at 5 retailers as of November 5, 2026, with prices from £2,462 to £3,666, a £1,204 spread on the same certified stone. 77 Diamonds lists it at £3,666. 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

1.28
Carat
I
Colour
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle36°
Pavilion angle40.8°
OriginNatural
Grading LabGIA
CertificateGIA 6515401647
Dimensions6.90 × 6.85 × 4.30 mm
L/W Ratio1.01
Star length50%
Lower girdle80%
Top View
6.90 mm6.85 mm1.28 ctI / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 6515401647
Side View
Table 58.0%Crown 36°Girdle: MED-STKPavilion 40.8°Culet: NoneDepth 62.8%

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 5
Current: £3,666 GBP|Low: £2,462 GBP|High: £3,726 GBP|Avg: £2,788 GBP|+0.8%
77 Diamonds
Retailer 2
Retailer 3
Retailer 4
November 6, 2026
Retailer 4£2,462 GBP
Retailer 3£2,495 GBP
Retailer 2£2,501 GBP
77 Diamonds£3,666 GBP

32 data points across 4 retailers

5 retailers£2,462 GBP to £3,666 GBP

A
Cheapest Retailer
-
£2,462 GBP
A
Retailer 2
-
£2,495 GBP
View
A
Retailer 3
-
£2,501 GBP
View
A
Retailer 4
-
£2,616 GBP
View
Most Expensive
B
77 Diamonds
RBZMMCC8BAK · Nov 6
£3,666 GBP
View
4 more retailers have this diamond
Prices start from £2,462 GBPSave up to £1,204 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
1.28ct Round
£2,462 GBP