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

As of September 2026, 1.00 to 1.49ct J SI1 natural radiant diamonds typically cost £1,089 GBP to £3,284 GBP, with a median price of £1,764 GBP. There are currently 613 diamonds matching this specification available across retailers.

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

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1.00 to 1.49ct J SI1 Natural Radiant

Quick answer

As of September 2026, there are 613 natural radiant diamonds with J colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £1,089 GBP to £3,284 GBP, with a median of £1,764 GBP. At least 51 retailers stock this exact specification. Half of all listings fall between £1,222 GBP and £1,901 GBP per carat. The same specification in lab grown form lists at a median of about £1,153 GBP per carat.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Radiant natural stones in the index: 2,765 USD per carat, +6.0% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

613

Lowest Price

£598 GBP

Highest Price

£14,506 GBP

Average Price

£1,979 GBP

Market Intelligence

Retailers Selling

Price Spread

45.0%

Price Range

Price per carat distribution across retailers

$1,913/ct

10th Percentile

$1,271

Median

$1,913

90th Percentile

$3,000

Score Distribution

613 diamonds scored across 4 quality tiers

Excellent

34 (5.5%)

Very Good

133 (21.7%)

Good

160 (26.1%)

Average

286 (46.7%)

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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

Save 27%

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