How much does a 3.00 to 4.99ct I SI2 natural cushion diamond cost?

As of November 2026, 3.00 to 4.99ct I SI2 natural cushion diamonds typically cost $32,396 NZD to $102,075 NZD, with a median price of $52,389 NZD. There are currently 112 diamonds matching this specification available across retailers.

Where can I find the best price on a I SI2 cushion diamond?

About 43% of these diamonds are available at multiple retailers, with an average price spread of 37%. A comparison tool like Carat Hunter lets you see all the prices side by side.

3.00 to 4.99ct I SI2 Natural Cushion

Quick answer

As of November 2026, there are 112 natural cushion diamonds with I colour and SI2 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run $32,396 NZD to $102,075 NZD, with a median of $52,389 NZD. At least 51 retailers stock this exact specification, and 43% of the stones appear at more than one of them, with an average price spread of 37%. Half of all listings fall between $13,443 NZD and $19,505 NZD per carat. The same specification in lab grown form lists at a median of about $1,195 NZD per carat. Over the last 30 days the median price moved -0.7% and the number of listings moved +13.4%.

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: November 2026

Available

112

Lowest Price

$19,359 NZD

Highest Price

$218,973 NZD

Average Price

$61,504 NZD