How much does a 0.75 to 0.99ct E SI1 lab grown radiant diamond cost?

As of October 2026, 0.75 to 0.99ct E SI1 lab grown radiant diamonds typically cost £162 GBP to £534 GBP, with a median price of £313 GBP. There are currently 51 diamonds matching this specification available across retailers.

Where can I find the best price on a E SI1 radiant diamond?

About 40% of these diamonds are available at multiple retailers, with an average price spread of 88%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct E SI1 Lab Grown Radiant

Quick answer

As of October 2026, there are 51 lab grown radiant diamonds with E colour and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run £162 GBP to £534 GBP, with a median of £313 GBP. At least 35 retailers stock this exact specification, and 40% of the stones appear at more than one of them, with an average price spread of 88%. Half of all listings fall between £234 GBP and £522 GBP per carat. The same specification in natural form lists at a median of about £1,869 GBP per carat. Over the last 30 days the median price moved +0.9% and the number of listings moved +1.1%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, September 2026: natural diamonds at 2,335 USD per carat and lab-grown at 443 USD per carat, a natural to lab ratio of 5.3 to 1. Radiant lab grown stones in the index: 474 USD per carat, -2.1% month on month. See the full index release

Figures come from current listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: October 2026

Available

Lowest Price

£107 GBP

Highest Price

£1,171 GBP

Average Price

£354 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

40.1%

Price Spread

88.5%

30-Day Price Trend

+0.9%

30-Day Supply Change

+1.1%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$433/ct

10th Percentile

$220

Median

$433

90th Percentile

$1,092

Score Distribution

75 diamonds scored across 4 quality tiers

Excellent

12 (16.0%)

Very Good

26 (34.7%)

Good

19 (25.3%)

Average

18 (24.0%)

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Related Specifications

D IF D VVS1 D VVS2 D VS1 D VS2 D SI1 E IF E VVS1 E VVS2 E VS1 E VS2 E SI1 F IF F VVS1 F VVS2 F VS1 F VS2 F SI1 G IF G VVS1 G VVS2 G VS1 G VS2 G SI1 H IF H VVS1 H VVS2 H VS1 H VS2 H SI1 I IF I VVS1 I VVS2 I VS1 I VS2 I SI1