How much does a 5.00ct+ J SI2 natural round diamond cost?

As of October 2026, 5.00ct+ J SI2 natural round diamonds typically cost £36,429 GBP to £106,002 GBP, with a median price of £57,140 GBP. There are currently 130 diamonds matching this specification available across retailers.

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

About 38% of these diamonds are available at multiple retailers, with an average price spread of 48%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ J SI2 Natural Round

Quick answer

As of October 2026, there are 130 natural round diamonds with J colour and SI2 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run £36,429 GBP to £106,002 GBP, with a median of £57,140 GBP. At least 11 retailers stock this exact specification, and 38% of the stones appear at more than one of them, with an average price spread of 48%. Half of all listings fall between £6,599 GBP and £10,150 GBP per carat. Over the last 30 days the median price moved +0.4% and the number of listings moved +14.1%.

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. Round natural stones in the index: 2,248 USD per carat, +7.6% 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

130

Lowest Price

£19,052 GBP

Highest Price

£427,112 GBP

Average Price

£66,849 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

38.1%

Price Spread

48.3%

30-Day Price Trend

+0.4%

30-Day Supply Change

+14.1%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$9,793/ct

10th Percentile

$7,784

Median

$9,793

90th Percentile

$14,676

Score Distribution

342 diamonds scored across 4 quality tiers

Excellent

47 (13.7%)

Very Good

70 (20.5%)

Good

84 (24.6%)

Average

141 (41.2%)

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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