How much does a 5.00ct+ I SI2 natural princess diamond cost?

As of October 2026, 5.00ct+ I SI2 natural princess diamonds typically cost £24,203 GBP to £46,006 GBP, with a median price of £35,750 GBP. There are currently 4 diamonds matching this specification available across retailers.

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

About 26% of these diamonds are available at multiple retailers, with an average price spread of 41%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ I SI2 Natural Princess

Quick answer

As of October 2026, there are 4 natural princess diamonds with I colour and SI2 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run £24,203 GBP to £46,006 GBP, with a median of £35,750 GBP. At least 26 retailers stock this exact specification, and 26% of the stones appear at more than one of them, with an average price spread of 41%. Half of all listings fall between £5,795 GBP and £9,108 GBP per carat. Over the last 30 days the median price moved -4.3% and the number of listings moved -8.0%.

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. Princess natural stones in the index: 2,158 USD per carat, +5.7% 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

£23,534 GBP

Highest Price

£72,034 GBP

Average Price

£35,852 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

26.3%

Price Spread

40.8%

30-Day Price Trend

-4.3%

30-Day Supply Change

-8.0%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$10,877/ct

10th Percentile

$6,533

Median

$10,877

90th Percentile

$12,804

Score Distribution

11 diamonds scored across 4 quality tiers

Excellent

1 (9.1%)

Very Good

3 (27.3%)

Good

2 (18.2%)

Average

5 (45.5%)

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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