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

As of November 2026, 1.00 to 1.49ct J SI1 natural cushion diamonds typically cost £784 GBP to £2,440 GBP, with a median price of £1,347 GBP. There are currently 455 diamonds matching this specification available across retailers.

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

About 38% of these diamonds are available at multiple retailers, with an average price spread of 64%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct J SI1 Natural Cushion

Quick answer

As of November 2026, there are 455 natural cushion diamonds with J colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £784 GBP to £2,440 GBP, with a median of £1,347 GBP. At least 56 retailers stock this exact specification, and 38% of the stones appear at more than one of them, with an average price spread of 64%. Half of all listings fall between £919 GBP and £1,711 GBP per carat. The same specification in lab grown form lists at a median of about £753 GBP per carat. Over the last 30 days the median price moved +0.3% and the number of listings moved +6.8%.

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. Cushion natural stones in the index: 2,948 USD per carat, +1.7% 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: November 2026

Available

455

Lowest Price

£557 GBP

Highest Price

£5,508 GBP

Average Price

£1,517 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

38.3%

Price Spread

64.3%

30-Day Price Trend

+0.3%

30-Day Supply Change

+6.8%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$1,651/ct

10th Percentile

$1,011

Median

$1,651

90th Percentile

$2,943

Score Distribution

1.1K diamonds scored across 4 quality tiers

Excellent

157 (14.3%)

Very Good

219 (19.9%)

Good

286 (26.0%)

Average

439 (39.9%)

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Consider Instead

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

Lab-Grown J SI1Same specifications, lab-grown origin

Save 39%

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