How much does a 3.00 to 4.99ct G SI1 natural cushion diamond cost?

As of October 2026, 3.00 to 4.99ct G SI1 natural cushion diamonds typically cost £21,381 GBP to £54,177 GBP, with a median price of £30,736 GBP. There are currently 113 diamonds matching this specification available across retailers.

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

About 40% of these diamonds are available at multiple retailers, with an average price spread of 30%. A comparison tool like Carat Hunter lets you see all the prices side by side.

3.00 to 4.99ct G SI1 Natural Cushion

Quick answer

As of October 2026, there are 113 natural cushion diamonds with G colour and SI1 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run £21,381 GBP to £54,177 GBP, with a median of £30,736 GBP. At least 54 retailers stock this exact specification, and 40% of the stones appear at more than one of them, with an average price spread of 30%. Half of all listings fall between £8,559 GBP and £11,532 GBP per carat. The same specification in lab grown form lists at a median of about £306 GBP per carat. Over the last 30 days the median price moved -0.3% and the number of listings moved +15.5%.

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

113

Lowest Price

£11,807 GBP

Highest Price

£95,468 GBP

Average Price

£34,934 GBP