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

As of October 2026, 0.75 to 0.99ct I SI1 natural marquise diamonds typically cost $1,474 CAD to $4,555 CAD, with a median price of $2,833 CAD. There are currently 93 diamonds matching this specification available across retailers.

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

About 24% of these diamonds are available at multiple retailers, with an average price spread of 50%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct I SI1 Natural Marquise

Quick answer

As of October 2026, there are 93 natural marquise diamonds with I color and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run $1,474 CAD to $4,555 CAD, with a median of $2,833 CAD. At least 59 retailers stock this exact specification, and 24% of the stones appear at more than one of them, with an average price spread of 50%. Half of all listings fall between $2,673 CAD and $4,390 CAD per carat. The same specification in lab grown form lists at a median of about $797 CAD per carat. Over the last 30 days the median price moved +0.4% and the number of listings moved +10.6%.

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

$823 CAD

Highest Price

$8,586 CAD

Average Price

$2,950 CAD