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

As of October 2026, 0.20 to 0.49ct H SI2 natural marquise diamonds typically cost £190 GBP to £434 GBP, with a median price of £276 GBP. There are currently 215 diamonds matching this specification available across retailers.

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

About 36% of these diamonds are available at multiple retailers, with an average price spread of 30%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.20 to 0.49ct H SI2 Natural Marquise

Quick answer

As of October 2026, there are 215 natural marquise diamonds with H colour and SI2 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run £190 GBP to £434 GBP, with a median of £276 GBP. At least 13 retailers stock this exact specification, and 36% of the stones appear at more than one of them, with an average price spread of 30%. Half of all listings fall between £722 GBP and £984 GBP per carat. The same specification in lab grown form lists at a median of about £549 GBP per carat. Over the last 30 days the median price moved -6.9% and the number of listings moved -2.4%.

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

215

Lowest Price

£141 GBP

Highest Price

£778 GBP

Average Price

£303 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

36.4%

Price Spread

30.0%

30-Day Price Trend

-6.9%

30-Day Supply Change

-2.4%

Volatility (30d)

0.03

Price Range

Price per carat distribution across retailers

$1,173/ct

10th Percentile

$851

Median

$1,173

90th Percentile

$1,668

Score Distribution

551 diamonds scored across 4 quality tiers

Excellent

17 (3.1%)

Very Good

206 (37.4%)

Good

67 (12.2%)

Average

261 (47.4%)

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Consider Instead

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

H I1I1 inclusions are not visible without magnification

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Lab-Grown H SI2Same specifications, lab-grown origin

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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