How much does a 0.75 to 0.99ct I SI1 natural cushion diamond cost?

As of October 2026, 0.75 to 0.99ct I SI1 natural cushion diamonds typically cost €624 EUR to €2,329 EUR, with a median price of €1,155 EUR. There are currently 190 diamonds matching this specification available across retailers.

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

About 29% of these diamonds are available at multiple retailers, with an average price spread of 77%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct I SI1 Natural Cushion

Quick answer

As of October 2026, there are 190 natural cushion diamonds with I colour and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run €624 EUR to €2,329 EUR, with a median of €1,155 EUR. At least 58 retailers stock this exact specification, and 29% of the stones appear at more than one of them, with an average price spread of 77%. Half of all listings fall between €1,148 EUR and €2,507 EUR per carat. The same specification in lab grown form lists at a median of about €672 EUR per carat. Over the last 30 days the median price moved +1.4% and the number of listings moved +2.9%.

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

190

Lowest Price

€465 EUR

Highest Price

€4,814 EUR

Average Price

€1,366 EUR