How much does a 3.00 to 4.99ct I SI1 natural marquise diamond cost?

As of November 2026, 3.00 to 4.99ct I SI1 natural marquise diamonds typically cost $33,233 SGD to $73,049 SGD, with a median price of $48,748 SGD. There are currently 25 diamonds matching this specification available across retailers.

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

About 41% of these diamonds are available at multiple retailers, with an average price spread of 38%. A comparison tool like Carat Hunter lets you see all the prices side by side.

3.00 to 4.99ct I SI1 Natural Marquise

Quick answer

As of November 2026, there are 25 natural marquise diamonds with I colour and SI1 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run $33,233 SGD to $73,049 SGD, with a median of $48,748 SGD. At least 52 retailers stock this exact specification, and 41% of the stones appear at more than one of them, with an average price spread of 38%. Half of all listings fall between $13,761 SGD and $20,389 SGD per carat. The same specification in lab grown form lists at a median of about $395 SGD per carat. Over the last 30 days the median price moved -3.8% and the number of listings moved +31.9%.

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

Caratlytics Diamond Price Index, October 2026: natural diamonds at 2,202 USD per carat and lab-grown at 462 USD per carat, a natural to lab ratio of 4.8 to 1. Marquise natural stones in the index: 2,177 USD per carat, -4.2% 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: November 2026

Available

Lowest Price

$25,634 SGD

Highest Price

$103,859 SGD

Average Price

$50,465 SGD

Market Intelligence

Retailers Selling

Cross Retailer %

40.8%

Price Spread

37.6%

30-Day Price Trend

-3.8%

30-Day Supply Change

+31.9%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$13,769/ct

10th Percentile

$9,094

Median

$13,769

90th Percentile

$17,867

Score Distribution

53 diamonds scored across 4 quality tiers

Excellent

9 (17.0%)

Very Good

18 (34.0%)

Good

12 (22.6%)

Average

14 (26.4%)

Find Your Diamond

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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