How much does a 0.75 to 0.99ct I SI1 natural round diamond cost?

As of November 2026, 0.75 to 0.99ct I SI1 natural round diamonds typically cost €888 EUR to €2,587 EUR, with a median price of €1,437 EUR. There are currently 1,430 diamonds matching this specification available across retailers.

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

About 35% of these diamonds are available at multiple retailers, with an average price spread of 52%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct I SI1 Natural Round

Quick answer

As of November 2026, there are 1,430 natural round diamonds with I color and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run €888 EUR to €2,587 EUR, with a median of €1,437 EUR. At least 66 retailers stock this exact specification, and 35% of the stones appear at more than one of them, with an average price spread of 52%. Half of all listings fall between €1,519 EUR and €2,500 EUR per carat. The same specification in lab grown form lists at a median of about €1,244 EUR per carat. Over the last 30 days the median price moved -1.5% and the number of listings moved +6.5%.

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. Round natural stones in the index: 2,248 USD per carat, +7.6% 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

1,430

Lowest Price

€556 EUR

Highest Price

€5,043 EUR

Average Price

€1,625 EUR