How much does a 5.00ct+ I VS1 lab grown marquise diamond cost?

As of October 2026, 5.00ct+ I VS1 lab grown marquise diamonds typically cost £649 GBP to £8,262 GBP, with a median price of £2,762 GBP. There are currently 18 diamonds matching this specification available across retailers.

Where can I find the best price on a I VS1 marquise diamond?

About 33% of these diamonds are available at multiple retailers, with an average price spread of 107%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ I VS1 Lab Grown Marquise

Quick answer

As of October 2026, there are 18 lab grown marquise diamonds with I colour and VS1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run £649 GBP to £8,262 GBP, with a median of £2,762 GBP. At least 22 retailers stock this exact specification, and 33% of the stones appear at more than one of them, with an average price spread of 107%. Half of all listings fall between £212 GBP and £650 GBP per carat. Over the last 30 days the median price moved -11.9% and the number of listings moved +35.5%.

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

£457 GBP

Highest Price

£19,031 GBP

Average Price

£3,669 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

32.6%

Price Spread

106.8%

30-Day Price Trend

-11.9%

30-Day Supply Change

+35.5%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$546/ct

10th Percentile

$221

Median

$546

90th Percentile

$1,298

Score Distribution

30 diamonds scored across 4 quality tiers

Excellent

11 (36.7%)

Very Good

4 (13.3%)

Good

7 (23.3%)

Average

8 (26.7%)

Find Your Diamond

Search 18 I VS1 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