How much does a 0.75 to 0.99ct G SI1 lab grown marquise diamond cost?

As of October 2026, 0.75 to 0.99ct G SI1 lab grown marquise diamonds typically cost $287 USD to $663 USD, with a median price of $471 USD. There are currently 9 diamonds matching this specification available across retailers.

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

About 16% of these diamonds are available at multiple retailers, with an average price spread of 57%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct G SI1 Lab Grown Marquise

Quick answer

As of October 2026, there are 9 lab grown marquise diamonds with G color and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run $287 USD to $663 USD, with a median of $471 USD. At least 22 retailers stock this exact specification, and 16% of the stones appear at more than one of them, with an average price spread of 57%. Half of all listings fall between $369 USD and $639 USD per carat. The same specification in natural form lists at a median of about $2,893 USD per carat. Over the last 30 days the median price moved +0.2% and the number of listings moved +20.4%.

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

$277 USD

Highest Price

$1,184 USD

Average Price

$490 USD

Market Intelligence

Retailers Selling

Cross Retailer %

15.5%

Price Spread

56.9%

30-Day Price Trend

+0.2%

30-Day Supply Change

+20.4%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$475/ct

10th Percentile

$197

Median

$475

90th Percentile

$797

Score Distribution

19 diamonds scored across 3 quality tiers

Very Good

4 (21.1%)

Good

7 (36.8%)

Average

8 (42.1%)

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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