How much does a 0.20 to 0.49ct F SI2 natural marquise diamond cost?

As of October 2026, 0.20 to 0.49ct F SI2 natural marquise diamonds typically cost £222 GBP to £439 GBP, with a median price of £324 GBP. There are currently 718 diamonds matching this specification available across retailers.

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

About 40% 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.

0.20 to 0.49ct F SI2 Natural Marquise

Quick answer

As of October 2026, there are 718 natural marquise diamonds with F colour and SI2 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run £222 GBP to £439 GBP, with a median of £324 GBP. At least 27 retailers stock this exact specification, and 40% of the stones appear at more than one of them, with an average price spread of 57%. Half of all listings fall between £842 GBP and £1,478 GBP per carat. The same specification in lab grown form lists at a median of about £429 GBP per carat. Over the last 30 days the median price moved -6.2% and the number of listings moved +0.8%.

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

718

Lowest Price

£125 GBP

Highest Price

£957 GBP

Average Price

£335 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

39.6%

Price Spread

56.7%

30-Day Price Trend

-6.2%

30-Day Supply Change

+0.8%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$1,496/ct

10th Percentile

$937

Median

$1,496

90th Percentile

$2,880

Score Distribution

1.8K diamonds scored across 4 quality tiers

Excellent

80 (4.4%)

Very Good

797 (43.8%)

Good

289 (15.9%)

Average

652 (35.9%)

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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