How much does a 0.75 to 0.99ct J SI1 natural marquise diamond cost?

As of November 2026, 0.75 to 0.99ct J SI1 natural marquise diamonds typically cost £599 GBP to £2,019 GBP, with a median price of £1,286 GBP. There are currently 72 diamonds matching this specification available across retailers.

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

About 32% of these diamonds are available at multiple retailers, with an average price spread of 60%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct J SI1 Natural Marquise

Quick answer

As of November 2026, there are 72 natural marquise diamonds with J colour and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run £599 GBP to £2,019 GBP, with a median of £1,286 GBP. At least 54 retailers stock this exact specification, and 32% of the stones appear at more than one of them, with an average price spread of 60%. Half of all listings fall between £975 GBP and £1,712 GBP per carat. Over the last 30 days the median price moved -1.9% and the number of listings moved +14.9%.

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: November 2026

Available

Lowest Price

£338 GBP

Highest Price

£3,285 GBP

Average Price

£1,328 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

31.5%

Price Spread

59.8%

30-Day Price Trend

-1.9%

30-Day Supply Change

+14.9%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,649/ct

10th Percentile

$1,047

Median

$1,649

90th Percentile

$3,103

Score Distribution

239 diamonds scored across 4 quality tiers

Excellent

25 (10.5%)

Very Good

38 (15.9%)

Good

54 (22.6%)

Average

122 (51.0%)

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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