How much does a 0.75 to 0.99ct I SI2 natural marquise diamond cost?

As of October 2026, 0.75 to 0.99ct I SI2 natural marquise diamonds typically cost $944 USD to $2,645 USD, with a median price of $1,619 USD. There are currently 78 diamonds matching this specification available across retailers.

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

About 26% of these diamonds are available at multiple retailers, with an average price spread of 57%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct I SI2 Natural Marquise

Quick answer

As of October 2026, there are 78 natural marquise diamonds with I color and SI2 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run $944 USD to $2,645 USD, with a median of $1,619 USD. At least 48 retailers stock this exact specification, and 26% of the stones appear at more than one of them, with an average price spread of 57%. Half of all listings fall between $1,520 USD and $2,650 USD per carat. Over the last 30 days the median price moved -0.3% and the number of listings moved +12.0%.

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

$577 USD

Highest Price

$5,435 USD

Average Price

$1,740 USD

Market Intelligence

Retailers Selling

Cross Retailer %

25.9%

Price Spread

56.5%

30-Day Price Trend

-0.3%

30-Day Supply Change

+12.0%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$2,000/ct

10th Percentile

$1,248

Median

$2,000

90th Percentile

$3,398

Score Distribution

242 diamonds scored across 4 quality tiers

Excellent

31 (12.8%)

Very Good

51 (21.1%)

Good

53 (21.9%)

Average

107 (44.2%)

Find Your Diamond

Search 78 I SI2 marquise diamonds and compare prices.

Search Diamonds

Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

J SI2J colour is visually identical to I to the naked eye

Save 16%

Related Specifications

D IF D VVS1 D VVS2 D VS1 D VS2 D SI1 E IF E VVS1 E VVS2 E VS1 E VS2 E SI1 F IF F VVS1 F VVS2 F VS1 F VS2 F SI1 G IF G VVS1 G VVS2 G VS1 G VS2 G SI1 H IF H VVS1 H VVS2 H VS1 H VS2 H SI1 I IF I VVS1 I VVS2 I VS1 I VS2 I SI1