How much does a 0.75 to 0.99ct E SI1 natural marquise diamond cost?

As of October 2026, 0.75 to 0.99ct E SI1 natural marquise diamonds typically cost £1,260 GBP to £3,337 GBP, with a median price of £2,015 GBP. There are currently 87 diamonds matching this specification available across retailers.

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

About 27% of these diamonds are available at multiple retailers, with an average price spread of 47%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct E SI1 Natural Marquise

Quick answer

As of October 2026, there are 87 natural marquise diamonds with E colour and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run £1,260 GBP to £3,337 GBP, with a median of £2,015 GBP. At least 57 retailers stock this exact specification, and 27% of the stones appear at more than one of them, with an average price spread of 47%. Half of all listings fall between £1,901 GBP and £2,979 GBP per carat. The same specification in lab grown form lists at a median of about £304 GBP per carat. Over the last 30 days the median price moved -1.1% and the number of listings moved +2.1%.

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. Marquise natural stones in the index: 2,268 USD per carat, +10.8% 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

Lowest Price

£768 GBP

Highest Price

£4,936 GBP

Average Price

£2,159 GBP