How much does a 1.00 to 1.49ct H I1 lab grown marquise diamond cost?

As of September 2026, 1.00 to 1.49ct H I1 lab grown marquise diamonds typically cost £942 GBP to £2,888 GBP, with a median price of £1,304 GBP. There are currently 6 diamonds matching this specification available across retailers.

Where can I find the best price on a H I1 marquise diamond?

About 5% of these diamonds are available at multiple retailers, with an average price spread of 56%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct H I1 Lab Grown Marquise

Quick answer

As of September 2026, there are 6 lab grown marquise diamonds with H colour and I1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £942 GBP to £2,888 GBP, with a median of £1,304 GBP. At least 7 retailers stock this exact specification, and 5% of the stones appear at more than one of them, with an average price spread of 56%. Half of all listings fall between £1,150 GBP and £1,991 GBP per carat. The same specification in natural form lists at a median of about £2,826 GBP per carat.

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

1.00ct Marquise H I1, GIA, score 66 of 100, from £2,461 GBP

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Marquise lab grown stones in the index: 500 USD per carat, -14.7% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

Lowest Price

£766 GBP

Highest Price

£3,314 GBP

Average Price

£1,711 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

5.0%

Price Spread

56.5%

Price Range

Price per carat distribution across retailers

$1,892/ct

10th Percentile

$1,009

Median

$1,892

90th Percentile

$2,618

Score Distribution

6 diamonds scored across 2 quality tiers

Good

4 (66.7%)

Average

2 (33.3%)

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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