How much does a 3.00 to 4.99ct D SI1 natural cushion diamond cost?

As of September 2026, 3.00 to 4.99ct D SI1 natural cushion diamonds typically cost £23,493 GBP to £63,588 GBP, with a median price of £35,977 GBP. There are currently 247 diamonds matching this specification available across retailers.

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

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3.00 to 4.99ct D SI1 Natural Cushion

Quick answer

As of September 2026, there are 247 natural cushion diamonds with D colour and SI1 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run £23,493 GBP to £63,588 GBP, with a median of £35,977 GBP. At least 44 retailers stock this exact specification. Half of all listings fall between £9,551 GBP and £13,138 GBP per carat. The same specification in lab grown form lists at a median of about £278 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. Cushion natural stones in the index: 2,792 USD per carat, +1.1% 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

247

Lowest Price

£15,269 GBP

Highest Price

£117,032 GBP

Average Price

£38,853 GBP

Market Intelligence

Retailers Selling

Price Spread

31.1%

Price Range

Price per carat distribution across retailers

$15,566/ct

10th Percentile

$10,873

Median

$15,566

90th Percentile

$20,255

Score Distribution

247 diamonds scored across 4 quality tiers

Excellent

37 (15.0%)

Very Good

63 (25.5%)

Good

92 (37.2%)

Average

55 (22.3%)

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Lab-Grown D 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