How much does a 1.50 to 1.99ct I SI2 natural round diamond cost?

As of November 2026, 1.50 to 1.99ct I SI2 natural round diamonds typically cost €2,519 EUR to €8,543 EUR, with a median price of €4,657 EUR. There are currently 1,650 diamonds matching this specification available across retailers.

Where can I find the best price on a I SI2 round diamond?

About 46% of these diamonds are available at multiple retailers, with an average price spread of 54%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct I SI2 Natural Round

Quick answer

As of November 2026, there are 1,650 natural round diamonds with I color and SI2 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run €2,519 EUR to €8,543 EUR, with a median of €4,657 EUR. At least 60 retailers stock this exact specification, and 46% of the stones appear at more than one of them, with an average price spread of 54%. Half of all listings fall between €2,502 EUR and €4,302 EUR per carat. The same specification in lab grown form lists at a median of about €850 EUR per carat. Over the last 30 days the median price moved -1.5% and the number of listings moved +15.2%.

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

1,650

Lowest Price

€1,215 EUR

Highest Price

€18,976 EUR

Average Price

€5,191 EUR