Round|Natural|GIA

1.21ct J SI2 Round Natural Diamond

GD • J/SI2 • GIA 17427766

Certificate GIA 17427766

Diamond specifications and retailer prices

From £1,791 GBP
$2,400 USD
As of October 30, 2026
Save £1,733 GBP (49%) vs most expensive(unlock to see where)
11 retailers carry this diamond
Most expensive: £4,182 GBP at NZ Jewellers · As of September 28, 2026
View at NZ Jewellers

About this 1.21ct natural round diamond

This 1.21ct natural round sits in the classic one-carat band, graded J colour (near-colourless) and SI2 clarity (slightly-included), with a standard cut grade and certified by GIA 17427766. Listed at 11 retailers as of October 29, 2026, with a 97% spread between the cheapest and most expensive listing. That is exactly the kind of price-discovery gap Carat Hunter was built to surface. Cut grade matters more than carat or clarity for visible brilliance. If you can shift budget toward an Excellent or Ideal cut, do it before chasing higher colour or clarity.

The 4Cs

1.21
Carat
J
Colour
SI2
Clarity
Good
Cut

Specifications

CutGood
PolishVery Good
SymmetryVery Good
FluorescenceStrong
Crown angle33°
Pavilion angle40.2°
OriginNatural
Grading LabGIA
CertificateGIA 17427766
Dimensions6.91 × 6.94 × 4.04 mm
L/W Ratio1.00
Star length50%
Lower girdle85%
Key to symbols
Feather, Crystal, Knot
Top View
6.91 mm6.94 mm1.21 ctJ / SI2
OriginNatural
CutGood
PolishVery Good
SymmetryVery Good
FluorescenceStrong
CertificateGIA 17427766
Side View
Table 63.0%Crown 33°Girdle: STK-THKPavilion 40.2°Culet: NoneDepth 58.3%

Caratlytics Score

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

Price History

Last verified: Oct 30
Current: £2,126 GBP|Low: £1,539 GBP|High: £3,547 GBP|Avg: £2,230 GBP|+3.4%
Retailer 1
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
October 31, 2026
Retailer 5£1,539 GBP
Retailer 2£1,931 GBP
Retailer 6£1,935 GBP
Retailer 1£2,126 GBP
Retailer 3£2,353 GBP
Retailer 4£3,524 GBP

40 data points across 6 retailers

11 retailers£1,791 GBP to £3,524 GBP

B+
Cheapest Retailer
-
£1,791 GBP
$2,400 USD
B
Retailer 2
-
£1,931 GBP
View
B
Retailer 3
-
£1,935 GBP
A$3,988 AUD
View
Retailer 4
-
£2,001 GBP
$2,681 USD
View
Price last confirmed 32 days ago
Retailer 5
-
£2,078 GBP
$2,784 USD
View
Price last confirmed 32 days ago
B
Retailer 6
-
£2,126 GBP
View
Retailer 7
-
£2,308 GBP
$3,093 USD
View
Price last confirmed 32 days ago
B
Retailer 8
-
£2,353 GBP
€3,002 EUR
View
C
Retailer 9
-
£2,725 GBP
€3,477 EUR
View
C
Retailer 10
-
£3,524 GBP
View
Most Expensive
NZ Jewellers
0d78096f-79e7-4b7b-a025-93a553bf2cb8 · Sep 28
£4,182 GBP
$5,604 USD
View
Price last confirmed 33 days ago
10 more retailers have this diamond
Prices start from £1,791 GBPSave up to £1,733 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+
1.21ct Round
£1,791 GBP