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

As of October 2026, 5.00ct+ I SI1 lab grown cushion diamonds typically cost $2,451 USD to $4,654 USD, with a median price of $2,791 USD. There are currently 3 diamonds matching this specification available across retailers.

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

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5.00ct+ I SI1 Lab Grown Cushion

Quick answer

As of October 2026, there are 3 lab grown cushion diamonds with I color and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run $2,451 USD to $4,654 USD, with a median of $2,791 USD. The same specification in natural form lists at a median of about $16,454 USD per carat.

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 lab grown stones in the index: 516 USD per carat, +6.9% 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

Lowest Price

$2,366 USD

Highest Price

$28,146 USD

Average Price

$3,426 USD

Score Distribution

3 diamonds scored across 2 quality tiers

Very Good

1 (33.3%)

Good

2 (66.7%)

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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