How much does a 1.00 to 1.49ct J SI1 natural princess diamond cost?

As of October 2026, 1.00 to 1.49ct J SI1 natural princess diamonds typically cost £885 GBP to £2,657 GBP, with a median price of £1,394 GBP. There are currently 227 diamonds matching this specification available across retailers.

Where can I find the best price on a J SI1 princess diamond?

About 40% of these diamonds are available at multiple retailers, with an average price spread of 50%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct J SI1 Natural Princess

Quick answer

As of October 2026, there are 227 natural princess diamonds with J colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £885 GBP to £2,657 GBP, with a median of £1,394 GBP. At least 55 retailers stock this exact specification, and 40% of the stones appear at more than one of them, with an average price spread of 50%. Half of all listings fall between £973 GBP and £1,562 GBP per carat. The same specification in lab grown form lists at a median of about £598 GBP per carat. Over the last 30 days the median price moved -0.7% and the number of listings moved +10.4%.

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

227

Lowest Price

£640 GBP

Highest Price

£5,290 GBP

Average Price

£1,609 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

40.1%

Price Spread

49.6%

30-Day Price Trend

-0.7%

30-Day Supply Change

+10.4%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,591/ct

10th Percentile

$1,109

Median

$1,591

90th Percentile

$2,929

Score Distribution

601 diamonds scored across 4 quality tiers

Excellent

61 (10.1%)

Very Good

133 (22.1%)

Good

125 (20.8%)

Average

282 (46.9%)

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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