How much does a 0.20 to 0.49ct D SI1 natural marquise diamond cost?

As of October 2026, 0.20 to 0.49ct D SI1 natural marquise diamonds typically cost $444 AUD to $1,008 AUD, with a median price of $686 AUD. There are currently 1,410 diamonds matching this specification available across retailers.

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

About 43% 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.

0.20 to 0.49ct D SI1 Natural Marquise

Quick answer

As of October 2026, there are 1,410 natural marquise diamonds with D colour and SI1 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run $444 AUD to $1,008 AUD, with a median of $686 AUD. At least 27 retailers stock this exact specification, and 43% of the stones appear at more than one of them, with an average price spread of 38%. Half of all listings fall between $1,972 AUD and $2,837 AUD per carat. The same specification in lab grown form lists at a median of about $1,251 AUD per carat. Over the last 30 days the median price moved -5.2% and the number of listings moved -8.7%.

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

1,410

Lowest Price

$265 AUD

Highest Price

$2,133 AUD

Average Price

$723 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

42.8%

Price Spread

38.4%

30-Day Price Trend

-5.2%

30-Day Supply Change

-8.7%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$1,582/ct

10th Percentile

$1,063

Median

$1,582

90th Percentile

$2,533

Score Distribution

2.6K diamonds scored across 4 quality tiers

Excellent

220 (8.6%)

Very Good

579 (22.6%)

Good

843 (32.9%)

Average

923 (36.0%)

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Consider Instead

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

Lab-Grown D SI1Same 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