How much does a 5.00ct+ I SI1 lab grown cushion diamond cost?

As of September 2026, 5.00ct+ I SI1 lab grown cushion diamonds typically cost $3,442 USD to $127,652 USD, with a median price of $9,593 USD. There are currently 9 diamonds matching this specification available across retailers.

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

Compare prices across retailers on Carat Hunter to see all your options.

5.00ct+ I SI1 Lab Grown Cushion

Quick answer

As of September 2026, there are 9 lab grown cushion diamonds with I color and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run $3,442 USD to $127,652 USD, with a median of $9,593 USD. At least 12 retailers stock this exact specification. Half of all listings fall between $265 USD and $682 USD per carat. The same specification in natural form lists at a median of about $17,577 USD 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 lab grown stones in the index: 466 USD per carat, -14.7% 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

Lowest Price

$2,676 USD

Highest Price

$181,641 USD

Average Price

$47,820 USD

Market Intelligence

Retailers Selling

Price Spread

118.4%

Price Range

Price per carat distribution across retailers

$352/ct

10th Percentile

$195

Median

$352

90th Percentile

$920

Score Distribution

9 diamonds scored across 3 quality tiers

Very Good

4 (44.4%)

Good

3 (33.3%)

Average

2 (22.2%)

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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