How much does a 3.00 to 4.99ct I SI2 natural marquise diamond cost?

As of September 2026, 3.00 to 4.99ct I SI2 natural marquise diamonds typically cost $20,470 SGD to $73,812 SGD, with a median price of $42,150 SGD. There are currently 89 diamonds matching this specification available across retailers.

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

Compare prices across retailers on Carat Hunter to see all your options.

3.00 to 4.99ct I SI2 Natural Marquise

Quick answer

As of September 2026, there are 89 natural marquise diamonds with I colour and SI2 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run $20,470 SGD to $73,812 SGD, with a median of $42,150 SGD. At least 43 retailers stock this exact specification. Half of all listings fall between $11,070 SGD and $17,121 SGD per carat. The same specification in lab grown form lists at a median of about $8,849 SGD per carat.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Marquise natural stones in the index: 2,114 USD per carat, -8.8% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

Lowest Price

$18,202 SGD

Highest Price

$156,979 SGD

Average Price

$45,019 SGD

Market Intelligence

Retailers Selling

Price Spread

41.1%

Price Range

Price per carat distribution across retailers

$11,541/ct

10th Percentile

$6,752

Median

$11,541

90th Percentile

$15,015

Score Distribution

89 diamonds scored across 4 quality tiers

Excellent

13 (14.6%)

Very Good

37 (41.6%)

Good

18 (20.2%)

Average

21 (23.6%)

Find Your Diamond

Search 89 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 49%

Lab-Grown I SI2Same specifications, lab-grown origin

Save 40%

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