How much does a 5.00ct+ G SI1 lab grown radiant diamond cost?

As of October 2026, 5.00ct+ G SI1 lab grown radiant diamonds typically cost £538 GBP to £3,110 GBP, with a median price of £977 GBP. There are currently 46 diamonds matching this specification available across retailers.

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

About 60% of these diamonds are available at multiple retailers, with an average price spread of 74%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ G SI1 Lab Grown Radiant

Quick answer

As of October 2026, there are 46 lab grown radiant diamonds with G colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run £538 GBP to £3,110 GBP, with a median of £977 GBP. At least 11 retailers stock this exact specification, and 60% of the stones appear at more than one of them, with an average price spread of 74%. Half of all listings fall between £149 GBP and £292 GBP per carat. Over the last 30 days the median price moved -1.6% and the number of listings moved +78.3%.

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

£403 GBP

Highest Price

£7,415 GBP

Average Price

£1,435 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

60.0%

Price Spread

74.4%

30-Day Price Trend

-1.6%

30-Day Supply Change

+78.3%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$255/ct

10th Percentile

$139

Median

$255

90th Percentile

$575

Score Distribution

99 diamonds scored across 4 quality tiers

Excellent

30 (30.3%)

Very Good

18 (18.2%)

Good

17 (17.2%)

Average

34 (34.3%)

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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