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Round|Lab Grown|IGI

4.20ct D IF Round Lab Grown Diamond

ID • D/IF • IGI LG754594373

Shape and cutting style on the report: Round brilliant

Certificate IGI LG754594373

Diamond specifications and retailer prices

From £1,433 GBP
$1,908 USD
As of October 29, 2026
Save £16,274 GBP (92%) vs most expensive(unlock to see where)
17 retailers carry this diamond
Most expensive: £17,707 GBP at Brilliant Earth · As of October 29, 2026
View at Brilliant Earth

About this 4.2ct lab-grown round diamond

This 4.2ct lab-grown round sits in the three to five carat band, graded D colour (colourless) and IF clarity (flawless or internally-flawless), with a top-tier cut grade and certified by IGI LG754594373 or 754594373. Listed at 17 retailers as of October 29, 2026, with prices from £1,433 to £17,707, a £16,274 spread on the same certified stone. Brilliant Earth lists it at £17,707. Lab-grown prices in the 2ct and up range have fallen 40 to 60% over the last 18 months. Use the cross-retailer spread above to find the lowest current listing.

The 4Cs

4.20
Carat
D
Colour
IF
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle34.3°
Pavilion angle40.8°
OriginLab Grown
Grading LabIGI
CertificateIGI LG754594373
Dimensions10.35 × 10.39 × 6.37 mm
L/W Ratio1.00
Girdle conditionFaceted
Culet sizePointed
Cert comments
HEARTS & ARROWS As Grown - No indication of post-growth treatment This Laboratory Grown Diamond was created by High Pressure High Temperature (HPHT) growth process Type II
Top View
10.35 mm10.39 mm4.20 ctD / IF
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG754594373
Side View
Table 56.0%Crown 34.3°Girdle: MED-STKPavilion 40.8°Culet: NoneDepth 61.4%

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: Oct 29
Current: £17,707 GBP|Low: £1,433 GBP|High: £18,248 GBP|Avg: £4,700 GBP|-3.0%
Brilliant Earth
Retailer 2
Retailer 3
Retailer 4
Retailer 5
Retailer 6
Retailer 7
Retailer 8
Retailer 9
Retailer 10
Retailer 11
Retailer 12
Retailer 13
Retailer 14
Retailer 15
Retailer 16
Retailer 17
October 29, 2026
Retailer 14£1,433 GBP
Retailer 4£1,559 GBP
Retailer 15£1,735 GBP
Retailer 9£1,802 GBP
Retailer 12£2,155 GBP
Retailer 3£2,522 GBP
Retailer 13£2,603 GBP
Retailer 17£2,729 GBP
Retailer 8£2,757 GBP
Retailer 10£2,962 GBP
Retailer 5£3,830 GBP
Retailer 6£4,025 GBP
Retailer 11£4,596 GBP
Retailer 2£5,004 GBP
Retailer 7£8,118 GBP
Retailer 16£9,860 GBP
Brilliant Earth£17,707 GBP

33 data points across 17 retailers

17 retailers£1,433 GBP to £17,707 GBP

A
Cheapest Retailer
-
£1,433 GBP
$1,908 USD
A
Retailer 2
-
£1,559 GBP
$2,076 USD
View
A
Retailer 3
-
£1,735 GBP
$2,311 USD
View
A
Retailer 4
-
£1,802 GBP
$2,400 USD
View
Final sale: no returns
A
Retailer 5
-
£2,155 GBP
$2,870 USD
View
A
Retailer 6
-
£2,522 GBP
$3,358 USD
View
A
Retailer 7
-
£2,603 GBP
$3,466 USD
View
A
Retailer 8
-
£2,729 GBP
$3,634 USD
View
A
Retailer 9
-
£2,757 GBP
$3,671 USD
View
A
Retailer 10
-
£2,962 GBP
€3,757 EUR
View
A
Retailer 11
-
£3,830 GBP
$5,100 USD
View
A
Retailer 12
-
£4,025 GBP
A$8,246 AUD
View
Price last confirmed 7 days ago
A
Retailer 13
-
£4,596 GBP
$6,120 USD
View
B+
Retailer 14
-
£5,004 GBP
View
B+
Retailer 15
-
£8,118 GBP
A$16,632 AUD
View
Price last confirmed 21 days ago
B+
Retailer 16
-
£9,860 GBP
$13,130 USD
View
Most Expensive
B
Brilliant Earth
17680491Y · Oct 29
£17,707 GBP
$23,580 USD
View
16 more retailers have this diamond
Prices start from £1,433 GBPSave up to £16,274 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
4.20ct Round
£1,433 GBP