How much does a 0.50 to 0.74ct F SI1 lab grown marquise diamond cost?

As of October 2026, 0.50 to 0.74ct F SI1 lab grown marquise diamonds typically cost £89 GBP to £314 GBP, with a median price of £166 GBP. There are currently 25 diamonds matching this specification available across retailers.

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

About 59% of these diamonds are available at multiple retailers, with an average price spread of 84%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.50 to 0.74ct F SI1 Lab Grown Marquise

Quick answer

As of October 2026, there are 25 lab grown marquise diamonds with F colour and SI1 clarity in the 0.50 to 0.74ct range available across retailers worldwide. Prices typically run £89 GBP to £314 GBP, with a median of £166 GBP. At least 24 retailers stock this exact specification, and 59% of the stones appear at more than one of them, with an average price spread of 84%. Half of all listings fall between £242 GBP and £547 GBP per carat. The same specification in natural form lists at a median of about £1,278 GBP per carat. Over the last 30 days the median price moved +21.7% and the number of listings moved +16.0%.

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 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: October 2026

Available

Lowest Price

£69 GBP

Highest Price

£902 GBP

Average Price

£188 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

58.9%

Price Spread

84.2%

30-Day Price Trend

+21.7%

30-Day Supply Change

+16.0%

Volatility (30d)

0.03

Price Range

Price per carat distribution across retailers

$485/ct

10th Percentile

$246

Median

$485

90th Percentile

$1,090

Score Distribution

45 diamonds scored across 4 quality tiers

Excellent

9 (20.0%)

Very Good

13 (28.9%)

Good

15 (33.3%)

Average

8 (17.8%)

Find Your Diamond

Search 25 F SI1 marquise diamonds and compare prices.

Search Diamonds

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