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

As of November 2026, 3.00 to 4.99ct G SI1 natural marquise diamonds typically cost £23,980 GBP to £53,623 GBP, with a median price of £32,043 GBP. There are currently 22 diamonds matching this specification available across retailers.

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

About 38% of these diamonds are available at multiple retailers, with an average price spread of 25%. A comparison tool like Carat Hunter lets you see all the prices side by side.

3.00 to 4.99ct G SI1 Natural Marquise

Quick answer

As of November 2026, there are 22 natural marquise diamonds with G colour and SI1 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run £23,980 GBP to £53,623 GBP, with a median of £32,043 GBP. At least 52 retailers stock this exact specification, and 38% of the stones appear at more than one of them, with an average price spread of 25%. Half of all listings fall between £10,713 GBP and £13,796 GBP per carat. The same specification in lab grown form lists at a median of about £308 GBP per carat. Over the last 30 days the median price moved -0.1% and the number of listings moved +30.4%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, October 2026: natural diamonds at 2,202 USD per carat and lab-grown at 462 USD per carat, a natural to lab ratio of 4.8 to 1. Marquise natural stones in the index: 2,177 USD per carat, -4.2% 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

Lowest Price

£18,884 GBP

Highest Price

£116,100 GBP

Average Price

£37,013 GBP