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

As of September 2026, 3.00 to 4.99ct I SI2 natural cushion diamonds typically cost HK$145,245 HKD to HK$399,259 HKD, with a median price of HK$231,107 HKD. There are currently 187 diamonds matching this specification available across retailers.

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

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

3.00 to 4.99ct I SI2 Natural Cushion

Quick answer

As of September 2026, there are 187 natural cushion diamonds with I colour and SI2 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run HK$145,245 HKD to HK$399,259 HKD, with a median of HK$231,107 HKD. At least 45 retailers stock this exact specification. Half of all listings fall between HK$60,754 HKD and HK$88,663 HKD per carat. The same specification in lab grown form lists at a median of about HK$6,633 HKD 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

187

Lowest Price

HK$86,729 HKD

Highest Price

HK$968,121 HKD

Average Price

HK$261,135 HKD