How much does a 0.75 to 0.99ct J SI2 lab grown round diamond cost?

As of October 2026, 0.75 to 0.99ct J SI2 lab grown round diamonds typically cost £294 GBP to £723 GBP, with a median price of £506 GBP. There are currently 6 diamonds matching this specification available across retailers.

Where can I find the best price on a J SI2 round diamond?

About 29% of these diamonds are available at multiple retailers, with an average price spread of 51%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct J SI2 Lab Grown Round

Quick answer

As of October 2026, there are 6 lab grown round diamonds with J colour and SI2 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run £294 GBP to £723 GBP, with a median of £506 GBP. At least 17 retailers stock this exact specification, and 29% of the stones appear at more than one of them, with an average price spread of 51%. Half of all listings fall between £533 GBP and £915 GBP per carat. The same specification in natural form lists at a median of about £1,069 GBP per carat. Over the last 30 days the median price moved -23.7% and the number of listings moved -76.8%.

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. Round lab grown stones in the index: 414 USD per carat, -5.0% 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

£216 GBP

Highest Price

£1,036 GBP

Average Price

£519 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

28.6%

Price Spread

51.1%

30-Day Price Trend

-23.7%

30-Day Supply Change

-76.8%

Volatility (30d)

0.19

Price Range

Price per carat distribution across retailers

$996/ct

10th Percentile

$367

Median

$996

90th Percentile

$1,864

Score Distribution

8 diamonds scored across 4 quality tiers

Excellent

1 (12.5%)

Very Good

2 (25.0%)

Good

4 (50.0%)

Average

1 (12.5%)

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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