Round|Natural|GIA

1.28ct I SI1 Round Natural Diamond

EX • I/SI1 • GIA 2556020066

Certificate GIA 2556020066

Diamond specifications and retailer prices

From $4,074 USD
As of November 6, 2026
6 retailers carry this diamond
Most expensive: $5,255 USD at Cape Diamonds · As of October 12, 2026
View at Cape 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 2556020066. Listed at 6 retailers as of November 6, 2026. 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
Color
SI1
Clarity
Excellent
Cut

Specifications

CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle36.5°
Pavilion angle41°
OriginNatural
Grading LabGIA
CertificateGIA 2556020066
Dimensions6.85 × 6.90 × 4.36 mm
L/W Ratio1.01
Star length50%
Top View
6.85 mm6.90 mm1.28 ctI / SI1
OriginNatural
CutExcellent
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateGIA 2556020066
Side View
Table 56.0%Crown 36.5°Girdle: THN-STKPavilion 41°Culet: NoneDepth 63.4%

Caratlytics Score

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B+
Very Good
Strong quality and value balance
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Price History

Last verified: Nov 6
Current: $5,255 USD|Low: $3,450 USD|High: $6,082 USD|Avg: $4,512 USD|+5.1%
Cape Diamonds
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
October 15, 2026
Retailer 11$3,450 USD
Retailer 8$3,745 USD
Retailer 9$4,074 USD
Retailer 5$4,393 USD
Retailer 3$4,420 USD
Retailer 12$4,420 USD
Retailer 6$4,446 USD
Retailer 2$4,471 USD
Retailer 4$4,570 USD
Retailer 7$4,940 USD
Cape Diamonds$5,255 USD
Retailer 10$6,082 USD

22 data points across 12 retailers

6 retailers

Retailer 1
-
$3,450 USD
Price last confirmed 25 days ago
B+
Retailer 2
-
$4,074 USD
View
Retailer 3
-
$4,393 USD
View
Price last confirmed 23 days ago
Retailer 4
-
$4,446 USD
View
Price last confirmed 25 days ago
Retailer 5
-
$4,940 USD
View
Price last confirmed 24 days ago
Most Expensive
Cape Diamonds
cert_2556020066 · Oct 12
$5,255 USD
ZAR 84,899 ZAR
View
Price last confirmed 25 days ago
5 more retailers have this diamond
Prices start from $4,074 USD

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+
1.28ct Round
$4,074 USD