How much does a 0.20 to 0.49ct I SI1 lab grown marquise diamond cost?

As of November 2026, 0.20 to 0.49ct I SI1 lab grown marquise diamonds typically cost €100 EUR to €158 EUR, with a median price of €129 EUR. There are currently 1 diamonds matching this specification available across retailers.

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

About 86% of these diamonds are available at multiple retailers, with an average price spread of 93%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.20 to 0.49ct I SI1 Lab Grown Marquise

Quick answer

As of November 2026, there are 1 lab grown marquise diamonds with I colour and SI1 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run €100 EUR to €158 EUR, with a median of €129 EUR. At least 13 retailers stock this exact specification, and 86% of the stones appear at more than one of them, with an average price spread of 93%. Half of all listings fall between €404 EUR and €908 EUR per carat. The same specification in natural form lists at a median of about €1,118 EUR per carat. Over the last 30 days the median price moved -7.4% and the number of listings moved -0.9%.

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

0.40ct Marquise I SI1, IGI, grade A, from €93 EUR

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 lab grown stones in the index: 485 USD per carat, -3.2% 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

€93 EUR

Highest Price

€965 EUR

Average Price

€129 EUR

Market Intelligence

Retailers Selling

Cross Retailer %

85.7%

Price Spread

93.2%

30-Day Price Trend

-7.4%

30-Day Supply Change

-0.9%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$605/ct

10th Percentile

$312

Median

$605

90th Percentile

$1,876

Score Distribution

2 diamonds scored across 2 quality tiers

Excellent

1 (50.0%)

Very Good

1 (50.0%)

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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