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Radiant|Lab Grown|IGI

1.78ct E IF Radiant Lab Grown Diamond

ID • E/IF • IGI LG620418140

Shape and cutting style on the report: Cut cornered rectangular modified brilliant

Certificate IGI LG620418140

Diamond specifications and retailer prices

From $354 USD
As of October 27, 2026
Save $3,496 USD (91%) vs most expensive(unlock to see where)
27 retailers carry this diamond
Most expensive: $3,850 USD at Brilliant Earth · As of October 28, 2026
View at Brilliant Earth

About this 1.78ct lab-grown radiant diamond

This 1.78ct lab-grown radiant sits in the one-and-a-half to two carat band, graded E colour (colourless) and IF clarity (flawless or internally-flawless), with a top-tier cut grade and certified by IGI LG620418140 or 620418140. Listed at 27 retailers as of October 27, 2026, with prices from $354 to $3,850, a $3,496 spread on the same certified stone. Brilliant Earth lists it at $3,850. Compare the cross-retailer prices above before buying. The same certified stone often varies 15 to 40% across stores.

The 4Cs

1.78
Carat
E
Color
IF
Clarity
Ideal
Cut

Specifications

CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
Crown angle44.4°
Pavilion angle33.8°
OriginLab Grown
Grading LabIGI
CertificateIGI LG620418140
Dimensions8.17 × 6.07 × 4.09 mm
L/W Ratio1.35
Culet sizePointed
Cert comments
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
8.17 mm6.07 mm1.78 ctE / IF
OriginLab Grown
CutIdeal
PolishExcellent
SymmetryExcellent
FluorescenceNone
CertificateIGI LG620418140
Side View
Table 64.0%Crown 44.4°Girdle: MediumPavilion 33.8°Culet: NoneDepth 67.4%

Caratlytics Score

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A
Excellent
Excellent quality and great value
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Price History

Last verified: Oct 27
Current: $3,850 USD|Low: $340 USD|High: $3,860 USD|Avg: $1,219 USD|-0.3%
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
Retailer 18
October 29, 2026
Retailer 4$354 USD
Retailer 9$411 USD
Retailer 6$439 USD
Retailer 10$439 USD
Retailer 12$455 USD
Retailer 3$585 USD
Retailer 14$590 USD
Retailer 13$755 USD
Retailer 16$762 USD
Retailer 2$791 USD
Retailer 11$1,020 USD
Retailer 18$1,288 USD
Retailer 8$1,412 USD
Retailer 7$1,660 USD
Retailer 15$1,718 USD
Retailer 5$1,737 USD
Retailer 17$2,690 USD
Brilliant Earth$3,850 USD

35 data points across 18 retailers

27 retailers$354 USD to $3,850 USD

A
Cheapest Retailer
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$354 USD
A
Retailer 2
-
$396 USD
View
Final sale: no returns
A
Retailer 3
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$411 USD
View
A
Retailer 4
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$439 USD
View
A
Retailer 5
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$439 USD
View
A
Retailer 6
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$455 USD
£358 GBP
View
A
Retailer 7
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$585 USD
View
A
Retailer 8
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$590 USD
View
A
Retailer 9
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$671 USD
€639 EUR
View
A
Retailer 10
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$705 USD
View
A
Retailer 11
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$755 USD
ZAR 12,196 ZAR
View
A
Retailer 12
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$762 USD
€726 EUR
View
A
Retailer 13
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$791 USD
£623 GBP
View
A
Retailer 14
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$929 USD
View
Price last confirmed 15 days ago
A
Retailer 15
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$1,020 USD
A$1,569 AUD
View
B+
Retailer 16
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$1,288 USD
View
B+
Retailer 17
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$1,385 USD
View
B+
Retailer 18
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$1,412 USD
View
B+
Retailer 19
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$1,454 USD
View
B+
Retailer 20
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$1,660 USD
View
B+
Retailer 21
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$1,686 USD
View
B+
Retailer 22
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$1,707 USD
£1,344 GBP
View
Price last confirmed 30 days ago
B+
Retailer 23
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$1,718 USD
£1,353 GBP
View
B+
Retailer 24
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$1,737 USD
A$2,673 AUD
View
Price last confirmed 21 days ago
B+
Retailer 25
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$1,851 USD
View
B+
Retailer 26
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$2,690 USD
View
Price last confirmed 8 days ago
Most Expensive
B
Brilliant Earth
16509820A · Oct 28
$3,850 USD
View
26 more retailers have this diamond
Prices start from $354 USDSave up to $3,496 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.

A
1.78ct Radiant
$354 USD