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 HK$126,441 HKD to HK$448,225 HKD, with a median price of HK$253,328 HKD. There are currently 92 diamonds matching this specification available across retailers.

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

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3.00 to 4.99ct I SI2 Natural Marquise

Quick answer

As of September 2026, there are 92 natural marquise diamonds with I colour and SI2 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run HK$126,441 HKD to HK$448,225 HKD, with a median of HK$253,328 HKD. At least 44 retailers stock this exact specification. Half of all listings fall between HK$67,834 HKD and HK$106,246 HKD per carat. The same specification in lab grown form lists at a median of about HK$54,431 HKD 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

HK$112,065 HKD

Highest Price

HK$965,644 HKD

Average Price

HK$274,385 HKD

Market Intelligence

Retailers Selling

Price Spread

42.4%

Price Range

Price per carat distribution across retailers

$11,538/ct

10th Percentile

$6,825

Median

$11,538

90th Percentile

$15,225

Score Distribution

92 diamonds scored across 4 quality tiers

Excellent

15 (16.3%)

Very Good

34 (37.0%)

Good

21 (22.8%)

Average

22 (23.9%)

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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 44%

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