How much does a 1.50 to 1.99ct I SI1 natural marquise diamond cost?

As of October 2026, 1.50 to 1.99ct I SI1 natural marquise diamonds typically cost $7,492 CAD to $24,892 CAD, with a median price of $12,204 CAD. There are currently 74 diamonds matching this specification available across retailers.

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

About 33% of these diamonds are available at multiple retailers, with an average price spread of 39%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct I SI1 Natural Marquise

Quick answer

As of October 2026, there are 74 natural marquise diamonds with I color and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $7,492 CAD to $24,892 CAD, with a median of $12,204 CAD. At least 58 retailers stock this exact specification, and 33% of the stones appear at more than one of them, with an average price spread of 39%. Half of all listings fall between $7,414 CAD and $10,975 CAD per carat. The same specification in lab grown form lists at a median of about $1,351 CAD per carat. Over the last 30 days the median price moved -4.3% and the number of listings moved +18.4%.

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

$5,053 CAD

Highest Price

$39,376 CAD

Average Price

$14,618 CAD