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

As of October 2026, 1.00 to 1.49ct J SI1 natural radiant diamonds typically cost £1,105 GBP to £3,195 GBP, with a median price of £1,780 GBP. There are currently 191 diamonds matching this specification available across retailers.

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

About 38% 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 Radiant

Quick answer

As of October 2026, there are 191 natural radiant diamonds with J colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £1,105 GBP to £3,195 GBP, with a median of £1,780 GBP. At least 57 retailers stock this exact specification, and 38% of the stones appear at more than one of them, with an average price spread of 50%. Half of all listings fall between £1,191 GBP and £1,919 GBP per carat. The same specification in lab grown form lists at a median of about £363 GBP per carat. Over the last 30 days the median price moved -0.9% and the number of listings moved +16.9%.

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 natural stones in the index: 3,091 USD per carat, +13.2% 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

191

Lowest Price

£719 GBP

Highest Price

£6,396 GBP

Average Price

£1,968 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

37.9%

Price Spread

50.3%

30-Day Price Trend

-0.9%

30-Day Supply Change

+16.9%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,926/ct

10th Percentile

$1,312

Median

$1,926

90th Percentile

$3,555

Score Distribution

572 diamonds scored across 4 quality tiers

Excellent

51 (8.9%)

Very Good

112 (19.6%)

Good

101 (17.7%)

Average

308 (53.8%)

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Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

J SI2SI2 inclusions are not visible without magnification

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Lab-Grown J SI1Same specifications, lab-grown origin

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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