How much does a 1.50 to 1.99ct L SI1 natural marquise diamond cost?

As of November 7, 2026, 1.50 to 1.99ct L SI1 natural marquise diamonds typically cost £1,781 GBP to £3,828 GBP, with a median price of £2,509 GBP. There are currently 52 diamonds matching this specification available across retailers.

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

About 33% of these diamonds are available at multiple retailers, with an average price spread of 35%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct L SI1 Natural Marquise

Quick answer

As of November 7, 2026, there are 52 natural marquise diamonds with L colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run £1,781 GBP to £3,828 GBP, with a median of £2,509 GBP. Half of all listings fall between £1,441 GBP and £2,019 GBP per carat. Over the last 30 days the median price moved -0.4% and the number of listings moved +6.8%.

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 140 retailers. The index is a monthly release.

Last updated: November 7, 2026

Available

Lowest Price

£1,621 GBP

Highest Price

£7,195 GBP

Average Price

£2,756 GBP

Market Intelligence

Cross Retailer %

32.7%

Price Spread

35.1%

30-Day Price Trend

-0.4%

30-Day Supply Change

+6.8%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$2,204/ct

10th Percentile

$1,589

Median

$2,204

90th Percentile

$3,194

Score Distribution

52 diamonds scored across 4 quality tiers

Excellent

2 (3.8%)

Very Good

9 (17.3%)

Good

21 (40.4%)

Average

20 (38.5%)

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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