How much does a 1.50 to 1.99ct G SI1 lab grown marquise diamond cost?

As of October 2026, 1.50 to 1.99ct G SI1 lab grown marquise diamonds typically cost $278 USD to $1,331 USD, with a median price of $671 USD. There are currently 7 diamonds matching this specification available across retailers.

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

About 20% of these diamonds are available at multiple retailers, with an average price spread of 102%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct G SI1 Lab Grown Marquise

Quick answer

As of October 2026, there are 7 lab grown marquise diamonds with G color and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $278 USD to $1,331 USD, with a median of $671 USD. At least 29 retailers stock this exact specification, and 20% of the stones appear at more than one of them, with an average price spread of 102%. Half of all listings fall between $311 USD and $766 USD per carat. The same specification in natural form lists at a median of about $7,741 USD per carat. Over the last 30 days the median price moved +13.5% and the number of listings moved +28.8%.

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

$169 USD

Highest Price

$2,230 USD

Average Price

$829 USD

Market Intelligence

Retailers Selling

Cross Retailer %

20.5%

Price Spread

101.6%

30-Day Price Trend

+13.5%

30-Day Supply Change

+28.8%

Volatility (30d)

0.05

Price Range

Price per carat distribution across retailers

$448/ct

10th Percentile

$174

Median

$448

90th Percentile

$898

Score Distribution

27 diamonds scored across 4 quality tiers

Excellent

2 (7.4%)

Very Good

3 (11.1%)

Good

7 (25.9%)

Average

15 (55.6%)

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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