How much does a 1.50 to 1.99ct F SI1 natural cushion diamond cost?

As of October 2026, 1.50 to 1.99ct F SI1 natural cushion diamonds typically cost £3,309 GBP to £9,375 GBP, with a median price of £5,863 GBP. There are currently 258 diamonds matching this specification available across retailers.

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

About 31% of these diamonds are available at multiple retailers, with an average price spread of 57%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct F SI1 Natural Cushion

Quick answer

As of October 2026, there are 258 natural cushion diamonds with F colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run £3,309 GBP to £9,375 GBP, with a median of £5,863 GBP. At least 60 retailers stock this exact specification, and 31% of the stones appear at more than one of them, with an average price spread of 57%. Half of all listings fall between £2,632 GBP and £4,671 GBP per carat. The same specification in lab grown form lists at a median of about £353 GBP per carat. Over the last 30 days the median price moved -2.6% and the number of listings moved +5.2%.

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: October 2026

Available

258

Lowest Price

£2,079 GBP

Highest Price

£18,688 GBP

Average Price

£6,159 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

31.0%

Price Spread

57.4%

30-Day Price Trend

-2.6%

30-Day Supply Change

+5.2%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$4,735/ct

10th Percentile

$2,836

Median

$4,735

90th Percentile

$7,586

Score Distribution

635 diamonds scored across 4 quality tiers

Excellent

79 (12.4%)

Very Good

138 (21.7%)

Good

148 (23.3%)

Average

270 (42.5%)

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Consider Instead

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

F SI2SI2 inclusions are not visible without magnification

Save 26%

Lab-Grown F SI1Same specifications, lab-grown origin

Save 90%

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