How much does a 5.00ct+ G SI1 natural cushion diamond cost?

As of September 2026, 5.00ct+ G SI1 natural cushion diamonds typically cost £51,042 GBP to £117,685 GBP, with a median price of £77,443 GBP. There are currently 76 diamonds matching this specification available across retailers.

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

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

5.00ct+ G SI1 Natural Cushion

Quick answer

As of September 2026, there are 76 natural cushion diamonds with G colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run £51,042 GBP to £117,685 GBP, with a median of £77,443 GBP. At least 37 retailers stock this exact specification. Half of all listings fall between £11,526 GBP and £16,682 GBP per carat. The same specification in lab grown form lists at a median of about £255 GBP 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

Lowest Price

£29,519 GBP

Highest Price

£281,635 GBP

Average Price

£82,499 GBP